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11 International Symposium on The 2001 Bhuj Earthquake and Advances in Earthquake Science (AES 2011) (22-27 January 2011) LOCAL ORGANIZING COMMITTEE: Chairman : Ravi Saxena,Add. Chief Secretary, DST, Government of Gujarat Secretary : B.K. Rastogi, Director General, ISR, Gandhinagar Members : T.P. Singh, Director, BISAG A.M. Prabhakar, Director, Gujcost, Ahmedabad Dilip Gadhvi, Executive Director, Science City, Ahmedabad Jwalant Trivedi, Deputy Secretary, DST, Government of Gujarat NATIONAL ADVISORY COMMITTEE: Harsh K.Gupta, Panikkar Professor, NGRI, Hyderabad Sudhir Jain, Director, Indian Institute of Technology, Gandhinagar V. P. Dimri, Distinguished Scientist, NGRI, Hyderabad B. Bhattacharjee, Member, National Disaster Management Authority, New Delh J. R. Kayal, CSIR Emeritus Scientist, Jadavpur University, Kolkata B. R. Arora, Former Director, Wadia Institute of Himalayan Geology, Dehradun A.K. Singhvi, Outstanding Scientist & Dean, PRL, Ahmedabad Ajit Tyagi, Director General, India Meteorological Department, New Delhi B. K. Bansal, Advisor and Head (Seismology), Ministry of Earth Science, New Delhi R. K. Chadha, Scientist, National Geophysical Research Institute, Hyderabad O.P. Mishra, Geophysicist, Geological Survey of India, Kolkata INTERNATIONAL ADVISORY COMMITTEE: Alik Ismail-Zadeh, Secretary General, IUGG Wu Zhongliang, President, IASPEI Roger Bilham, Colorado University, USA Mark Petersen, Head Federal Earthquake Hazard Mitigation Program. USGS, Colorado Satish Singh, Instituite de Physique de Globe de Paris, France Ramesh P Singh, Vice-President, IUGG Georisk Commission T. Yokoi, Senior Research Scientist, IISEE, BRI, Japan Arantza Ugalde, Geological Survey of Cataluniya, Spain Amod Mani Dixit, President, National Centre for Disaster Management, Nepal i

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13 AES-2011 PROGRAM 21 st January, 2011 Time Program 15:00 18:00 Registration 18:30 19:30 Light & Sound show at Akshar Dham 20:00 21:00 Icebreaker 22 nd January, :00 10:00 Registration 10:00 11:00 Inauguration 1:00 12:00 High Tea Time Session Subject Place 12:00 13:00 ISES Lecture & Special Lecture 1 Auditorium 13:00 14:00 Lunch 14:00-16:00 Special Lectures(2,3,4,5,6,7) Auditorium 16:00-18:00 S1-8 Papers Bhuj Earthquake and Aftershock Studies Conference Room No-2 15:00-18:30 S16-14 Papers IGCP Session on Archeoseismology 16:00-18:30 Poster session in Display Area 19:00 21:00 Gala Dinner 08:00 8 :30 Registration 23 rd January, :30 09:30 Special Lectures(8,9) Auditorium 09:30 10:30 S4-6 Papers Paleoseismology and Historical Seismology 10:30 11:00 Tea 11:00 13:00 S14-7 Papers Ground Response Studies for Nuclear Power Plants 13:00 14:00 Lunch S12-7 Papers Remote Sensing, GPS & InSAR S4-6 Papers(continued) Paleoseismology and Historical Seismology 14:00 17:00 S3-12 Papers Seismicity and Earthquake Source Processes 17:00 17:30 Tea/Snacks S9-17 Papers Seismic Hazard Assessment / Microzonation Conference Room No-1 Conference Room No-1 Auditorium Conference Room No-2 Conference Room No-1 Auditorium Conference Room No-1 S2-11 Papers Intraplate Seismicity Conference Room No-2 17:30 18:30 Special Lecture 10 Auditorium 18:30 19:30 Poster session in Display area 20:00 21:00 Dinner iii

14 24 th January, 2011 Time Session Subject Place 08:30 10:30 S11-7 Papers Earth s Interior, Structure & Dynamics 10:30 11:00 Tea S5-18 Papers Earthquake Precursors and Prediction Studies S8-8 Papers Earthquake Ground Motion and Damaging Earthquakes 11:00 13:00 S7-9 Papers Real Time Seismology, Early Warning & Loss Assessment 13:00 14:00 Lunch S5-18 Papers(continued) Earthquake Precursors and Prediction Studies Auditorium Conference Room No-1 Conference Room No-2 Auditorium Conference Room No-1 S15-4 Papers Tsunami Modeling Conference Room No-2 14:00 15:00 Special Lectures (11, 12, 13) Auditorium 15:00 17:00 S6-6 Papers Seismic Wave Propagation, Amplification and Basin Effect 17:00 17:30 Tea S10-7 Papers Tectonics and Crustal Movements S13-4 Papers Exploration for Oil and Crustal Structure 17:30 18:30 Concluding Session 20:00 21:00 Dinner Auditorium Conference Room No-1 Conference Room No-2 iv

15 ISES Lecture Special-1 Special-2 Special-3 Special-4 Special-5 Special-6 Special-7 Special-8 Special-9 Special-10 Special-11 Special-12 Special-13 Special Lectures Program on study of earthquake precursors in India Harsh Gupta, Panikkar Professor National Geophysical Research Institute,Hyderabad Shailesh Nayak Secretary, Ministry of Earth Sciences, New Delhi India s tsunami warning system: A success story Harsh Gupta, Panikkar Professor, National Geophysical Research Institute,Hyderabad Time-varying Tsunami Characteristics in Wavelet Domain V.P.Dimri, Distiguished Scientist, NGRI, Hydrabad Making of probabilistic seismic hazard map of India for the Bureau of Indian Standards B.K. Rastogi, Director General Institute of Seismological Research, Gandhinagar New probabilistic seismic hazard map of India R.N.Iyengar Center of Disaster Mitigation,Jain University, Baglaore-Kanakapura Road, Jakkasandra Recommendations for earthquake safety and retrofitting in Gujarat Padmashree Dr. Anand S. Arya (FNA, FNAE; Ex-National Seismic Advisor MHA, GoI-UNDP Professor Emeritus of Earthquake Engineering, IIT- Roorkee Nuclear power program of India and seismic safety of Nuclear Power Plants S K Jain CMD, NPCIL, Mumbai Structure, tectonics & active faults of Kutch rift basin, Gujarat, Western India S. K. Biswas Formerly: Director, KD Malviya Institute Petroleum Exploration,ONGC, Dehradun A testable model for intraplate earthquakes Pradeep Talwani(Retired) Dept. of Earth and Ocean Sciences, University of South Carolina, Columbia,USA Space inputs in disaster monitoring, mitigation and early warning. R.R.Navalgund Director, Space Application Center,ISRO,Ahmedabad Bhuj 2001 earthquake revisiting existing knowledge of structural behavior of traditional and new constructions, geological hazards of the Kutch region and the regime of seismic safety Alpa Sheth, Seismic Advisor,GSDMA,Gandhinagar The road to seismic safety Sudhir Jain Director, IIT Gandhinagar. Bhuj earthquake and role of CEPT University in post disaster scenario V. R. Shah (H.O.D Structural Design department, CEPT University, Ahmedabad Page No v

16 LIST OF PAPERS Kn: Keynote (20 min), I: Invited (15 min), C: Contributed (15min), P: Poster Page No. S1: Bhuj Earthquake and Aftershock Studies 1 Session Chairman: Mark Petersen Co-Chairman: Prabhas Pande Session Date: 22 nd January, 2011 Session Time: 16:00 18:00 S1_Kn1 S1_Kn2 S1_Kn3 S1_I1 S1_I2 S1_I3 S1_C1 S1_C2 S1_P1* S1_P2* Geoseismological investigation of 26 January 2001 Bhuj earthquake Prabhas Pande Geological Survey of India Delineation of crustal and lithospheric structures below the Kachchh.. Prantik Mandal National Geophysical Research Institute (CSIR), Hyderabad, India Seismic source of the 2001 Bhuj earthquake.. J R Kayal Indian School of Mines, Dhanbad. Impact of the 2001 M 7.7 Bhuj earthquake on hazard estimates in the US.. Mark Petersen U.S. Geological Survey, Golden, CO, USA Targeting the future great earthquakes : Global monitoring and the 26 January 2001 Bhuj, India case Vladimir G. Kossobokov et al. International Institute of Earthquake Prediction Theory and Mathematical Geophysics, Relocation of aftershocks of the 2001 Bhuj earthquake. Jim Mori et al Disaster Prevention Research Institute, Kyoto University, Japan. Probabilistic assessment of earthquake hazards using method of moments in the Kutch Jayant N. Tripathi Department of Earth and Planetary Sciences, University of Allahabad Detection complex networks of Bhuj earthquake (2001) and aftershocks. MostafaAllameh-Zadeh Seismology Department, IIEES Ground deformation and liquefaction structures formed due to 2001 Kachchh earthquake R.D. Shah et al. M.G. Science Institute, Navrangpura, Ahmedabad Seismicity monitoring of Bhuj aftershocks Santosh Kumar et al. Institute of Seismological Research, Gandhinagar S2:Intraplate Seismicity 7 Session Chairman: O. P. Mishra Co-Chairman:Bijendra Singh Session Date: 23 rd January, 2011 Session Time: 14:00 17:00 S2_Kn1 Seismotectonics of Bhuj earthquake of 2001 based on gravity and magnetic signatures.. D. C. Mishra National Geophysical Research Institute (CSIR), Hyderabad 7 vi

17 S2_I1 S2_C1 S2_C2 S2_C3 S2_C4 S2_C5 S2_C6 S2_C7 S2_C8 S2_C9 S2_P1* S2_P2* S2_P3* Geodynamics of the Kachchh Basin: Gravity- Magnetic Perspective D.V. Chandrasekhar and B. Singh National Geophysical Research Institute (CSIR), Hyderabad ) Geodetic crustal strain patterns over the Satpura mountain belt. S. Mohanty Department of Applied Geology, Indian School of Mines, Dhanbad, India Mafic crust and earthquake activity in the high velocity Indian shield. O.P. Pandey National Geophysical Research Institute,Uppal Road, Hyderabad An intraplate earthquake and the study of ground response analysis.. H.S.Mandal Earthquake Risk Evaluation Centre, India Meteorological Department, New Delhi Study of the shallow seismic activity of offshore southern and eastern Sri Lanka Shantha S.N. Gamage and S.A.D.L.K. Suraweera Department of Physics, University of Sri Jayewardenepura, Sri Lanka Assessing the intraplate origin for subduction zone mega-thrust earthquake Prosanta K. Khan Department of Applied Geophysics, Indian School of Mines, Dhanbad Crustal strain pattern over a part of southern India and its implication for seismotectonics ArijitBarik and S. Mohanty Department of Applied Geology, Indian School of Mines, Dhanbad, India Intermittent micro-seismic activity in the vicinity of Nanded city of west central India Md. Babar Shaikh,Maharashtra Structural controls on the intraplate seismicity of the Kachchh region, India. SushmitaSinha and S. Mohanty Department of Applied Geology, Indian School of Mines, Dhanbad, India Improved Seismicity Trends in the Koyna-Warna Region through Earthquake Relocation using hypodd. G. Srijayanthi et al. National Geophysical Research Institute, Hyderabad Unusually large number of earthquake sequences in Saurashtra since B.K. Rastogi et al. Institute of Seismological Research, Gandhinagar Spatiotemporal complexity of intraplate seismicity: a reverie and its multifarious ArjunTiwari Applied Geophysics, Indian School of Mines Dhanbad New insight into crustal heterogeneity beneath the 2001 Bhuj earthquake A. P. Singh et al. Institute of Seismological Research (ISR), Raisan, Gandhinagar, Gujarat S3: Seismicity and Earthquake Source Processes 16 Session Chairman: J R Kayal Co-Chairman: Prantik Mandal Session Date: 23 rd January, 2011 Session Time: 14:00 17:00 S3_I1 Seismic hazard assessment for Karachi, Pakistan MonaLisa and 2M.Qasim Jan Department of Earth Sciences, Quaid-i-Azam University, Islamabad, Pakistan. 16 vii

18 S3_I2 S3_C1 S3_C2 S3_C3 S3_C4 S3_C5 S3_C6 S3_C7 S3_C8 S3_C9 An overview of the seismic activity and associated hazards in South-America. Omar J. Pérez, Carlos Rodríguezand José L. Alonso Simon Bolivar University, Dpt. Earth Sciences, Caracas, Venezuela A study of source parameters, site amplification functions and attenuation parameter Manisha, Dinesh Kumar and S.S. Teotia Department of Geophysics, Kurukshetra University Kurukshetra, India Source parameters and scaling relations for small earthquakes in Kumaon Himalaya K. Sivaram et al. National Geophysical Research Institute, Hyderabad India Apatial statistics: a technique to constrain earthquake cluster.. Basab Mukhopadhyay Geological Survey of India Estimation of seismic source parameters in northeast (NE) India from body wave spectra Alok Kumar Mohapatra and William Kumar Mohanty Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur Analysis of the seismic activity of el asnam region F.Bellalem et al. Seismological Dept.Survey.CRAAG.BP 63 Bouzareah Algiers-Algeria Stress pattern in the Kangra-Chamba region of Northwest Himalaya. Dilip Kr Yadav et al.. Wadia Institute of Himalayan Geology, Dehradun , India. Estimation of earthquake source parameters and site response.. Prantik Mandal and Utpal Dutta National Geophysical Research Institute (CSIR), Hyderabad, India Earthquake interevent time clustering inferred from mixed models. Talbi A. et al. Centre de Recherche en AstronomieAstrophysiqueetGéophysique, CRAAG, Algeria. Triggering is fine but what causes earthquakes in Koyna-Warna region? V.K. Gahalaut and Kalpna Gahalaut National Geophysical Research Institute, Uppal Road, Hyderabad S3_C10 Source characteristics of Delhi earthquake (ML:4.3) of 25th Nov., 2007 Rajesh Prakash, A. K. Shukla and R. K. Singh India Meteorological Department, New Delhi 23 S3_P1* S3_P2* S3_P3* S3_P4* Waveform inversion of local earthquakes using broadband data of Koyna. D. Shashidhar et al. National Geophysical Research Institute, Uppal Road, Hyderabad Remotely triggered seismicity due to the 2001 Bhuj earthquake G. Surve and G. Mohan Dr. K. S. Krishnan Geomagnetic Research Laboratory (I.I.G), Leelapur Road, Chamanganj, Allahabad Evidence for transverse tectonics in Sikkim Himalaya from seismicity. Pinki Hazarika et al. National Geophysical Research Institute, Uppal Road, Hyderabad Evidence for right lateral strike slip environment in Kutch rift... Ch. Nagabhushana Rao et al. Institute of Seismological Research, Raisan, Gandhinagar, Gujarat , India viii

19 S4 : Paleoseismology and Historical Seismology 26 Session Chairman: V C Thakur Co-Chairman: Javed Malik Session Date: 23 rd January, 2011 Session Time: 09:30 10:30 & 11:00-13:00 S4_Kn1 S4_I1 S4_C1 S4_C2 S4_C3 S4_C4 S4_P1* Luminescence dating in paleoseismology and neotectonics: an overview A.K. Singhvi et al. Physical Research Laboratory, Ahmedabad, India Active faults in Kachchh region and issue on the seismic hazard assessment M. Morino et al. OYO International Corporation; Partitioning of convergence in Northwest sub Himalaya... V.C. Thakur et al. Wadia Institute of Himalayan Geology, Dehradun , India. Paleoseismic investigations in the Kopili Lineament Zone, Northeast India. Devender Kumar et al. National Geophysical Research Institute, Uppal Road, Hyderabad Paleoseismology along an intraplate fault: Talas-Fergana, Tien-Shan mountains, central Asia. Derek Rust et al. School of Earth and Environmental Sciences, University of Portsmouth, UK. Active fault mapping using high resolution geophysical field investigation in Kachchh A. K. Gupta et al. Institute of Seismological Research, Gandhinagar, Gujarat, India Morphotectonic control on drainage network evolution in the Upper Narmada Valley Girish Ch. Kothyari and B. K. Rastogi Institute of Seismological Research, Raisan, Gandhinagar, Gujarat India S5: Earthquake Precursors and Prediction Studies 30 Session Chairman: B R Arora Co-Chairman: R K Chadha Session Date: 24 th January, 2011 Session Time: 08:30 10:30 &11:00-13:00 S5_I1 S5_I2 S5_C1 Changing Scenario of earthquake precursory research B. R. Arora Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun, India Monitoring well water level changes what did we learn from our experiences in India R K Chadha National Geophysical Research Institute, Hyderabad Soil-gas geochemistry for earthquake monitoring and fault studies in Taiwan. Vivek Walia et al. 1National Center for Research on Earthquake Engineering,Taiwan, S5_C2 Fractal correlation dimension analysis to identify precursory pattern prior to 15th July 2009 S.K. Mondal, R. Meena and and P. N. S. Roy Department of Applied Geophysics, Indian School of Mines, Dhanbad , Jharkhand, 32 S5_C3 S5_C4 Investigations of anomalous signals prior to large earthquakes. WenBin Shen et al. Department of Geophysics, School of Geodesy and Geomatics, Wuhan University, Chin Changes observed prior and after the Gujarat earthquake of 26 January.. Ramesh P. Singh and Waseem Mehdi School of Earth and Environmental Sciences,Chapman University,USA ix

20 S5_C5 S5_C6 S5_C7 S5_C8 S5_C9 S5_C10 S5_C11 S5_C12 S5_C13 S5_C14 S5_C15 S5_C16 Application of acoustic sounding in earthquake precursor detection lessons from Bhuj. H.N. Dutta and B.S. Gera Roorkee Engineering & Management Technology Institute, Shamli. Anomalous changes in groundwater and soil-gas radon concentrations.. R.C. Ramola and Sushil Kumar Wadia Institute of Himalaya Geology, Dehra,India Anomalous variations of fof2 during Bhuj earthquake of 26 January, 2001 O.P. Singh et al. Department of Physics, Faculty of Engineering & Technology, R.B.S. College, Signature of seismo-electromagnetic signals (ses) in prediction of earthquakes Vinod Kumar Kushwah Department of Physics, Hindustan College of Science & Technology, Farah, Mathura Precursory Earthquake Studies in Maharashtra, especially in Koyna Region Arun Bapat¹ and M.A.Ghatpande 2 1 1/11, Tara Residency, 20/2, Kothrud, Pune , 2 Formerly from MERI, Nashik Earthquake pre-cursory studies in Koyna-Warna region, India: some vital observations D.V. Reddy and P. Nagabhushanam National Geophysical Research Institute,Hyderabad Detection of possible precursors of the 2010 Chile earthquake using.. Jun Yi et al. Department of Geophysics, School of Geodesy and Geomatics, Wuhan University, China Seismic Acoustic Emission (SAE) as an earthquake precursor G. Suresh and R. S. Dattatrayam India Meteorological Department,, New Delhi Study of multi-parameter gas-geochemical precursor signals of a distant earthquake.. H. Chaudhuri et al. Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata, India. Predictability of valsad earthquake swarms Gujarat, India H.N.Srivastava, Formerly in India Meteorological Department Gujarat Engineering Research Institute,Vadodara The analysis of microseisms before the 2008 great Wenchuan earthquake. Xiao-GuangHao, Xiao-Gang Hu. Institute of Geodesy and Geophysics, ChineseAcademy of Sciences, China. Multi-parametric geophysical observations at Ghuttu, Garhwal Himalaya: Radon component V.M.Choubey Wadia Institute of Himalayan Geology S5_P1* Thermal and ionospheric anomalies associated with the Haiti earthquake of January 12, 2010 Suryanshu Choudhary, Shivalika Sarkar and A.K.Gwal Space Science Laboratory, Department of Physics 44 S5_P2* S5_P3* Earthquakes in UttranchalHimalaya, India Arun K Shandilya & AnuragShandilya Department of Applied Geology, Dr. Hari Singh Gour University, Sagar (M.P.) India Low field magnetic measurements: a modern tool for prediction of earthquake Dr Rajeev Vaghmare GRIIC, GERMI Gandhinagar x

21 S5_P4* S5_P5* Foreshock clustering as precursory pattern for the Kachchh earthquakes in Gujarat, India Sandeep Kumar Aggarwal et al Institute of Seismological Research, Village Raisan, Gandhinagar Status of superconducting gravimeter and MPGO network of Kachchh Arun Gupta, RashmiPradhan, M.S.B.S. Prasad and B.K.Rastogi Institute of Seismological Research, Raisan, Gandhinagar, Gujarat S6 : Seismic Wave propagation, Amplification and Basin Effect 47 Session Chairman: Praveen Malhotra Co-Chairman: MostafaAllameh-Zadeh Session Date: 24 th January, 2011 Session Time: 15:00 17:00 S6_C1 S6_C2 S6_C3 S6_C4 S6_C5 S6_C6 S6_P1* S6_P2* S6_P3* A possibility of site effects due to the past earthquakes at Anjar, Gujarat state, India. Fumio Kaneko et al. Oyo internation Corporation Determination of Site amplification in the Northern Iran from Inversion of Strong- Motion B. Hassani, H. Zafarani International Institute of Earthquake Engineering and Seismology, Iran. Estimation of dynamic properties of Lucknow soil T.G. Sitharam, S. M.Patil. Professor, Department of Civil Engineering, Indian Institute of Science, Bangalore, India Liquefaction susceptibility of lucknow soil T.G. Sitharam et al. Professor, Department of Civil Engineering, Indian Institute of Science, Bangalore, India. Site characterization: which dataset to use? Manish Shrikhande and SusantaBasu Department of Earthquake Engineering, Indian Institute of Technology Roorkee The ground effect of the Skopje 1963 earthquake. Apostol Poceski, R.Macedia Fac. of Civil Eng.Univ.Sent Cyril &Metodi, Skopje Attenuation of coda waves of local earthquakes in the Northeastern India Alok Kumar Mohapatra, William Kumar Mohanty Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur Spectral decay parameter (?) using the accelerograms of the earthquakes in Himalaya Renu Yadav, Kavita Rani, Gunjan Dhiman and Deepak Kumar Department of Geophysics, Kurukshetra University Kurukshetra,India Estimation of coda-q using a non-linear (Gauss-Newton) regression Savita Singh, Sumedha, Monika Wadhawan and Vandana Department of Geophysics, Kurukshetra University Kurukshetra, India S7 : Real Time Seismology, Loss Reduction and Early Warning 52 Session Chairman: R.S.Dattatrayam Co-Chairman: E. Hohnecker Session Date: 24 th January, 2011 Session Time: 11:00 13:00 S7_Kn1 Current trends in seismic instrumentation and earthquake monitoring in India R.S.Dattatrayam et al. India Meteorological Department, Ministry of Earth Sciences, Lodi Road, New Delhi 52 xi

22 S7_I1 S7_C1 S7_C2 S7_C3 S7_C4 S7_C5 S7_C6 S7_C7 EDIM earthquake disaster information system for the Marmara region, Turkey Wenzel F et al. Geophysical Institute, Karlsruher Institute of Technology (KIT), Seismic loss reduction/estimation technique for use in educational spaces Chandra Bhakuni QuakeSchool Consulting Pvt. Ltd., Navrangpura, Ahmedabad, Gujarat, India The seismic alert system of Mexico (SASMEX). Espinosa-Aranda J. M et al. Centro de Instrumentación y RegistroSímico, A. C., Mexico. Early warning system for transportation lines E. Hohnecker et al. Department of Railway Systems, Karlsruhe Institute of Technology, Germany. Seismo-tectonic interpretations for the Delhi region based on the data recorded at Delhi VivekMahadev and NeeluMathur Delhi Seismic Unit, Seismology Division, BARC, New Delhi Earthquake vulnerability assessment of Gujarat port sites viz-a-viz seismic disturbances Terala Srikanth et al. Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad, India. Performance analysis of mundra panipat pipeline crossing Kachhach mainland fault Vasudeo Govind Choudhary and Ramancharla Pradeep Kumar Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad, India. Rapid visual survey of existing buildings in Gandhidham and Adipur cities, Kachchh, Gujarat Terala Srikanth et al. Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad, India S8 : Earthquake Ground Motion and Damaging Earthquakes 58 Session Chairman: Kojiro Irikura Co-Chairman: Sumer Chopra Session Date: 24 th January, 2011 Session Time: 08:30 10:30 S8_I1 S8_C1 S8_C2 S8_C3 S8_C4 The great Sumatra earthquakes: Results from recent marine studies Satish C. Singh. Institut de Physique du Globe de Paris, France and University of Cambridge, UK Estimation of H/V ratio in different sites in northern Algeria with aftershock sequences. M.Mobarki et al. Seismological Dept,Algeria Ground motion parameters of Shillong plateau: One of the most seismically active zones... SaurabhBaruah et al. Geoscience Division, North-East Institute of Science and Technology (CSIR), Assam, India Characterization of seismic regime in NW Himalaya: Persistent and high seismicity in. Naresh Kumar et al. Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun, India Strong ground motion simulation of the 2001/01/26 Bhuj, India earthquake Tao-Ming Chang National Center for Earthquake Engineering Research, Taipei, Taiwan xii

23 S8_C5 S8_C6 S8_C7 S8_P1* S8_P2* Recipe for predicting strong ground motions for inland mega fault earthquakes Kojiro IRIKURA and Susumu KRAHASHI Aichi Institute of Technology & Kyoto University, Toyota, Aichi, Japan Estimation of damage to various types of buildings in Gujarat from a future large earthquake Sumer Chopra, Dinesh Kumar and B.K.Rastogi Institute of Seismological Research, Gandhinagar Strong motion simulation of great earthquake in the central seismic gap Kapil Mohan and A. Joshi Institute of Seismological Research, Gandhinagar, Gujarat(India) Attenuation relations for the Kumaon and Garhwal Himalaya, Uttarakhand, India A.Joshi et al. Department of Earth Science, Indian Institute of Technology Roorkee, Roorkee, India. Prediction of strong ground motion in the coastal and economically important regions... Kapil Mohan Institute of Seismological Research, Gandhinagar, Gujarat (India) S9: Seismic Hazard Assessment / Microzonation 64 Session Chairman: A. Peresan Co-Chairman 1: T G Sitharam Co-Chairman 2: Imtiyaz Parvez Session Date: 23 rd January, 2011 Session Time: 14:00 17:00 S9_I1 S9_I2 S9_I3 S9_I4 S9_I5 S9_I6 S9_I7 S9_C1 Seismic hazard assessment for Gandhidham; Kutch; Gujarat Fumio Kaneko et al. OYO International Corporation Seismic hazard assessment based on unified scaling law for earthquakes Anastasia K. Nekrasova and Vladimir G. Kossobokov International Institute of Earthquake Prediction Theory and Mathematical Geophysics Neo-deterministic seismic hazard techniques contributions to the alternative. Kouteva M et al. NIGGG-BAS, Sofia, Bulgaria Neo-deterministic seismic hazard and pattern recognition techniques Peresan et al. Department of Earth Sciences, University of Trieste,Triest., Ground motion at bedrock level in Delhi city from different earthquake scenarios Imtiyaz A Parvez et al. (CMMACS), NAL Belur Campus, Bangalore, India Probabilistic seismic hazard macrozonation of India Prof. T.G. Sitharam, Mr.SreevalsaKolathayar and Dr. K.S. Vipin Department of Civil Engineering, Indian Institute of Science, Bangalore Study of the local site effects on seismic hazard using deterministic and probabilistic approaches: A case. Prof. T.G. Sitharam, Mr. Naveen James, and Dr. K.S Vipin Department of Civil Engineering, Indian Institute of Science Seismic hazard deaggregation in terms of magnitude, distance and azimuth M. Hamdache et al. Departement Étudeset Surveillance Sismique, CRAAG, Algiers xiii

24 S9_C2 S9_C3 S9_C4 S9_C5 S9_C6 S9_C7 S9_C8 S9_C9 S9_C10 S9_P1* S9_P2* S9_P3* S9_P4* S9_P5* S9_P6* Determination site effect of Zarqa City-Jordan based on microtremors field measurements: A microzonation study Waleed Eid Olimat Natural Resources Authority (NRA), Jordan Seismological Observatory (JSO),Jordan. Probabilistic seismic hazard analysis for mitigating societal risk from earthquakes Dr. Praveen K. Malhotra, P.E. StrongMotions Inc., Sharon, MA, USA Influence of source and epicentral distance on local seismic response in Kolkata city, India. William K. Mohanty et al. Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur Neo-deterministic and probabilistic seismic hazard assessments E. Zuccolo et al. European Centre for Training and Research in Earthquake Engineering,Italy. Evaluation of site classification for soils in Lucknow urban centre Abhishek Kumar et al. Department of Civil Engineering, Indian Institute of Science, Bangalore,India. Site response studies in the Andaman and Nicobar islands K Sushini et al. National Geophysical Research Institute,Uppal Road, Hyderabad Analysis of embedded pipeline induced by earthquake excitation under. Goktepe F et al. Department of Civil Engineering, Sakarya University, Sakarya, Turkey Seismic hazard assessment of Gujarat. K. S. Vipin et al. Department of Civil Engineering, Indian Institute of Science (IISc), Bangalore Earthquake hazard assessment for public safety Lalliana Mualchin Retired Chief Seismologist, Office of Earthquake Engineering, California Dept. of Transportion, Sacramento, California and Seismic Consultant to the Govt. of Mizoram, India, Disaster Mangement & Rehabilitation Dept., Govt. of Mizoram, Aizawl) Geo-informatics based conceptualization of earthquake disaster management system Ajeet P. Pandey, R.K. Singh and A.K. Shukla Earthquake Risk Evaluation Center, India Meteorological Department, New Delhi Probability of occurrence of largest earthquakes in Jharkhand and nearby region.. AkashAdwani et al. Dept. of Applied Geophysics, Indian School of Mines, Dhanbad (India). Preliminary site characterization through integration of geophysical and geotechnical data at GIFT B.K. Rastogi et al. Institute of Seismological Research (ISR), Raisan, Gandhinagar, Gujarat, India Preliminary site characterization through integration of geophysical and geotechnical data at Dholera. B.K. Rastogi et al. Institute of Seismological Research (ISR), Raisan, Gandhinagar, Gujarat, India Estimation of liquefaction potential of Dholera region based on SPT N-values Sarda Maibam et al. Institute of Seismological Research, Raisan Village, Gandhinagar Vs30 and site amplification studies in Dholera SIR Region, Gujarat, India B. Sairam et al. Institute of Seismological Research, Raisan, Gandhinagar xiv

25 S10 : Tectonics and Crustal Movements 78 Session Chairman: H N Srivastava Co-Chairman: Y S Kim Session Date: 24 th January, 2011 Session Time: 15:00 17:00 S10_I1 S10_I2 S10_I3 S10_C1 S10_C2 S10_C3 S10_C4 S10_P1* Seismotectonics and velocity structure of the Kumaon - Garhwal Himalaya P. Mahesh et al. National Geophysical Research Institute (CSIR), Hyderabad, India New evidence of the involvement of the low density fluid phase in the deep crust seismicity M.V.Rodkin International Institute of Earthquake Prediction Theory and Mathematical Geophysics,Russia, Crustal configuration and seismo-tectonics of the Kutch rift basin from analysis Mita Rajaram and S.P.Anand Indian Institute of Geomagnetism, NewPanvel(W), Navi Mumbai. Seismotectonic studies of kachchh basin using gravity surveys after 2001 Bhuj earthquake Rashmi Pradhan et al. Institute of Seismological Research, Gandhinagar About the geophysical studies are being carryout by WIHG in the NW Himalaya. Sushil Kumar Wadia Institute of Himalaya Geology, Dehra Dun, India Fractal dimension and b-value mapping in NW Himalaya and adjoining regions. Sushil Kumar Wadia Institute of Himalaya Geology, Dehra Dun, India Stress pulse migration by viscoelastic process for long - distance delayed triggering of.. B.K. Rastogi Institute of Seismological Research, Gandhinagar, India Active deformation and lithotectonic model of Saurashtra Horst, Gujarat, India Girish Ch. Kothyari et al. Institute of Seismological Research, Gandhinagar, Gujarat, India S11 : Earth s interior, structure & dynamics 83 Session Chairman: M.Ravi Kumar Co-Chairman:WenBin Shen Session Date: 24 th January, 2011 Session Time: 08:30 10:30 S11_C1 S11_C2 S11_C3 Spatial distribution of scatterers in the crust of Kachchh region, Western India by inversion analysis of coda B. Sharma et al. Institute of Seismological Research, Raisan, Gandhinagar, India Moho depth variation in the Shillong-Mikir hills plateau in North Eastern region of India SaurabhBaruah and Dipok K. Bora Geoscience Division, CSIR North-East Institute of Science and Technology Seismic signatures of volcanism in the upper mantle beneath NW DVP G. Mohan Department of Earth Sciences, Indian Institute of Technology Bombay,Powai, Mumbai xv

26 S11_C4 S11_C5 S11_C6 S11_C7 Crustal structure and upper mantle deformation in eastern Himalayan syntaxis DevajitHazarika, B.R. Arora Wadia Institute of Himalayan Geology,Dehradun, India The signal of transition-zone anisotropy in the normal mode coupling. Xiao-gang HU, Xiao-guangHao Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics. Surface wave tomography across the Indian shield, Indo-Gangetic plains and the Himalayan. N. Purnachandra Rao et al. National Geophysical Research Institute, Uppal Road, Hyderabad Anisotropy of the Indian crust from splitting of Ps phases from the Moho Narendra Kumar et al. NGRI, Hyderabad S11_P1* A comparative study on seismic wave attenuation characteristics of Koyna, Chamoli And Gujarat regions Babita Sharma et al. Institute of Seismological Research, Raisan, Gandhinagar, India. S11_P2* Inversion of seismic intensity data for the determination of three-dimensional attenuation structures. Babita Sharma et al. Institute of Seismological Research, Gandhinagar S11_P3* S11_P4* Seismic evidences for underplating and uplifted crust beneath the Northwestern deccan volcanic province. K. Madhusudana Rao et al. Institute of Seismological Research, India. Shear wave splitting beneath the northwestern deccan volcanic province... K. Madhusudana Rao et al. Institute of Seismological Research, India S11_P5* Evaluation of the crustal structure of the Indus Block up to Saurashtra using GA inversion Vishwa Joshi et al. ISR, Gandhinagar. S11_P6* Shield like lithosphere of the lower Indus basin evaluated from observations of surface wave dispersion. Mukesh Chauhan et al. Institute of Seismological Research, Raisan, Gandhinagar, India S12: Remote Sensing, GPS & InSAR 91 Session Chairman: V.K.Gahalaut Co-Chairman: Mita Rajaram Session Date: 23 rd January, 2011 Session Time: 11:00 13:00 S12_I1 S12_C1 Weak mantle lithosphere in Kachchh, India probed by GPS... D. V. Chandrasekhar and Roland Bürgmann National Geophysical Research Institute (CSIR), Hyderabad, India SAR Interferometry detects post-seismic ground deformations related with 2001 Bhuj earthquake. Arun K. Saraf Department of Earth Sciences,Indian Institute of Technology Roorkee, ROORKEE, INDIA xvi

27 S12_C2 S12_C3 S12_C4 S12_C5 S12_C6 S12_P1* Ten years of GPS observations after 2001 Bhuj earthquake C.D. Reddy et al. Indian Institute of Geomagnetism, New Panvel, Navimumbai, India. Studies on seismic behaviour and associated topographic changes in NE India based. R. K. Sukhtankar et al. Department of Atmospheric and Space Sciences, Pune University, Pune Crustal deformation mapping in Kachchh, India using InSAR and GPS: Initial results K. M. Sreejith et al. Geosciences Division, Marine,Space Applications Centre (ISRO), Ahmedabad The Tehri Dam, Uttarakhand: crustal strain and implications in case of reservoir induced. Swapnamita C. Vaideswaran and Ajay Paul Wadia Institute of Himalayan Geology, Dehradun Satellite altimeter derived geoid / gravity and the lithospheric density anomaly Rajesh S et al. Geophysics Group, WadiaInsitute of Himalayan Geology, Dehradun Post-seismic deformation associated with the 2001 Bhuj earthquake Pallabee Choudhury et al. Institute of Seismological Research, Raisan, Gandhinagar S13: Exploration for Oil and Crustal Structure 96 Session Chairman: S.K.Biswas Co-Chairman: Satish Singh Session Date: 24 th January, 2011 Session Time: 15:00 17:00 S13_I1 S13_I2 S13_I3 S13_C1 S13_C2 S13_P1* S13_P2* S13_P3* On-land Kutch basin and its basement configuration from seismic refraction studies.. B. Rajendra Prasad Emeritus Scientist, (National Geophysical Research Institute, Uppal Road, Hyderabad, India.) Integration of geophysical data for exploration of hydrocarbons - GIS application T. Harinarayana et al. NGRI, Uppal Road, Hyderabad, India Impact of tectonics, sedimentation process and evolving trap style in Andaman island etc.. Sadip k Roy, IIT,Bombay Geophysical Investigations of the Gulf of Kachchh, Northwest India. D. Gopala Rao and N. Mahendar Geology Department, Osmania University, Hyderabad, India 2D-geoelectric subsurface structure in the surroundings of the epicenter zone of Kapil Mohan et al. Institute of Seismological Research, Raisan, Gandhinagar, Gujarat, India Identification of shallow geological features in the Wagad area (Kachchh) using 2D electrical survey Kapil Mohan et al. Institute of Seismological Research, Raisan, Gandhinagar, Gujarat (India) 2D electrical imaging survey to identify the shallow subsurface layer in the Gujarat international. Kapil Mohan et al. Institute of Seismological Research, Raisan, Gandhinagar, Gujarat (India) Passive Seismic Imaging of Petroleum Reservoir Mr.Sunjay, Exploration Geophysics,BHU, Varanasi,India xvii

28 S14: Ground Response Studies for Nuclear Power Plants 101 Session Chairman: A.G. Chhatre Co-Chairman: CVR Murty Session Date: 23 rd January, 2011 Session Time: 11:00-13:00 S14_I1 S14_I2 S14_I3 S14_I4 S14_I5 S14_C1 S14_C2 S14_P1* S14_P2* S14_P3* Near-field ground motion simulation for the 26th January 2001 Gujarat earthquake STG Raghukanth and B. Bhanu Teja Dept. of Civil Engineering, IIT Madras Displacement-based Design of Structures: a consistent framework of limiting-strain based design method C. V. R. Murty Department of Civil Engineering, Indian Institute of Technology Madras,Chennai Seismic Design of Bridges for Displacement Loading Rupen Goswami Department of Civil Engineering,Indian Institute of Technology Madras Earthquake Experience based performance of civil structures, piping systems, cable trays, ducting and mechanical, electrical, instrumentation & control equipment from industries in India Faisal Dastageer et. al NPCIL, Mumbai Seismic Analysis of a typical Nuclear Power Plant structure Apurba Mondal et. al Nuclear Power Corporation of India Ltd., Mumbai, India Design of distribution systems, viz., piping, cable trays and ducting. Faisal Dastageer et al. NPCIL, Mumbai Earthquake ground motion generation for nuclear power plant. Faisal Dastageer et al. NPCIL, Mumbai Estimation of spectral decay parameter kappa, seismic moment, stress drop, source dimension.. Santosh Kumar et al. Institute of Seismological Research, Gandhinagar Seismotectonic study to characterize the seismic sources in Gulf of Khambhat and prediction of strong Sandeep Kumar Aggarwal et al. Institute of Seismological Research, Gandhinagar. Site characterization using Vs30 and site amplification in Gujarat, India B. Sairam et al. Institute of Seismological Research, Raisan,Gandhinagar S15: Tsunami Modeling 108 Session Chairman: V.P.Dimri Co-Chairman: A. Buchmann Session Date: 24 th January, 2011 Session Time: 11:00 13:00 S15_C1 Hydrodynamic modelling of 2004 Indonesian and 1945 Macran Tsunamis. R. Rajaraman and S. Joseph Winston Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, INDIA. 108 xviii

29 S15_C2 Tsunami assessment of Indian nuclear coastal sites for Sumatra 2004 and Makran 1945 Tsunami events. R. K. Singh, P Sasidhar Reactor Safety Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India. 108 S15_C3 S15_C4 S15_P1* Development of paleo-tsunami database and hazard assessment for Indian subcontinent Akhilesh K. Verma and William K. Mohanty Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, India. Tsunami effect On Porbandar, Western Gujarat coast V. M. Patel et al. Ganpat University, GanpatVidyanagar, Mehsana , Gujarat, India. Numerical modeling of Arabian Sea tsunami propagation and its effect on the Gujarat A. P. Singh and B. K. Rastogi Institute of seismological research (ISR), Raisan, Gandhinagar, Gujarat (India) S16: IGCP Session on Archeoseismology 112 Session Chairman: Javed Malik Co-Chairman: M Kazmer Session Date: 22 nd January, 2011&23 rd January, 2011 Session Time: 14:00 17:00 &9:30-10:30 S16_Kn1 Archaeoseismology and the role of tectonics in the demise of the Indus Valley Civilization PradeepTalwani, Dept. of Earth and Ocean Sciences, University of South Carolina, Columbia, SC, USA. 112 S16_I1 S16_C1 S16_C2 S16_C3 S16_C4 S16_C5 S16_C6 Major Earthquake Occurrences in Archaeological Strata of Harappan Settlement at Dholavira (Kachchh, Gujarat) Ravindra Singh Bisht Former Joint Director General, Archaeological Survey of India, Ghaziabad Archaeological evidences for a 12th -14th century earthquake at Ahichhatra, Barreilly (U.P.), India Bhuvan Vikrama et al. Archaeologist, Archaeological Survey of India, Agra. Active fault influence on the evolution of landscape and drainage. Javed N. Malik Department of Civil Engineering, Indian Institute of Technology Kanpur,Uttar Pradesh, India. Signatures of active faulting in Southern peninsular India. Biju John et al. National Institute of Rock Mechanics, Kolar Gold Fields, India Macroseismic intensity assessment of 1885 AD historical earthquake of NW Kashmir Himalaya.. Bashir Ahmad et al. Department of Education, J&K, Srinagar, India Fault segmentation and propagation characteristics based on rupture patterns Jin-Hyuck Choi et al. GSGR, Dept. of Earth Environmental Sciences, Pukyong National University, Busan, Korea Preliminary study on active faults around Mandi region, NW Himalaya, India Javed N. Malik and Santiswarup Sahoo Department of Civil Engineering, Indian Institute of Technology, Kanpur, India xix

30 S16_C7 S16_C8 Archaeology of earthquakes at Mahasthanghar (Province of Bogra, Bangladesh) Bruno Helly et al. Directeur de recherche au CNRS (émérite), Maison de Archeoseismology of the A.D earthquake in Chiang Mai, northern Thailand. Miklos Kazmer and Kamol Sanittham Department of Palaeontology, Eotvos University, Hungary S16_C9 Paleoseismological analysis in north of Dushanbeh, Tajikistan (June 2010) H. Nazari et al. Geological survey of Iran, Seismotectonic group, Tehran, Iran S16_C10 Archaeo seismological approach based on stone heritages in Gyeongju, SE Korea. M. Lee and Y.-S. Kim Dept. of Geosciences, Pukyong National University, Busan, Korea S16_C11 S16_C12 Discover and the characteristic initially search of Gaixiaruins's nature distortion Vestige, Guzhen County et al. Seismological Administration of Anhui Province,Hefei,Anhui P.R.China Paleo-earthquake evidence from archaeological site in mesoseismal zone of 1819 Allah Bund event, Great Rann of Kachchh, Gujarat, Western India Malik J N et al. Department of Civil Engineering, Indian Institute of Technology Kanpur Miscellaneous 121 M_P1* M_P2* Specific yield-water level fluctuation method an effective tool for quantitative evaluation of groundwater resource a case study Syed Zaheer Hasan and M. Yusuf Farooqui GERMI, Gandhinagar and GSPC Gandhinagar Environmental studies using Electrical Resistivity Method Sunita Devi & Rupal Malik Institute of Seismological Research, Gandhinagar * Poster sessions have been scheduled at 17:00 hrs on 21 st January and at 18:30 hrs on 22 nd January. xx

31 S1: Bhuj Earthquake and Aftershocks Conveners : B.K. Rastogi, Prabhas Pande and Jim Mori THEME The 2001 M7.7 Bhuj earthquake is a rare great Stable Continental Region (SCR) earthquake studied through modern era seismographs. The well-determined mechanism indicated clear reverse faulting along a steep fault and inversion of tectonics from tensile stress (normal faulting) in the rift valley environment to compressive stress (thrusting) regime now. The rupture details have also been worked out. Over 10,000 aftershocks of M 1-5 have been precisely located and well-studied by modern era local seismograph network. Seismological studies include PS, Q and b-value tomography, Crustal structure, through travel time, surface-wave dispersion and Receiver Transfer Function, anisotropy study through shear-wave splitting, Geophysical surveys have established details of crustal structure besides sediment thickness and basement configuration. All these studies have given new insights to the understanding of seismogenesis of least understood SCR earthquakes. Papers are invited on the study of Bhuj earthquake and aftershocks and similar earthquake in other SCR regions as a comparative study. S1_Keynote-1 Geoseismological Investigation of 26 January 2001 Bhuj Earthquake Prabhas Pande (Geological Survey of India, JN Road, Kolkata, Of the intraplate seismic events, the 26 January 2001 Bhuj earthquake will be remembered as one of the deadliest, in which 13,805 human lives were lost, 1.77 lakh injured and a total of 1,205,198 houses fully or partly damaged in 16 districts of Gujarat state with an estimated overall loss of Rs. 28,423 crore. The brunt of the calamity was borne by five districts, namely Kachchh, Ahmadabad, Rajkot, Jamnagar and Surendranagar, where 99% of the total casualties and damage occurred. In the neighbouring parts of Sindhh Province of Pakistan, 40 human casualties were reported, whereas some buildings cracked in Karachi city as well. In the Kachchh District, the telecommunication links and power supply remained totally disrupted, road and rail links partially impaired and water supply snapped at many places. The Bhuj airbase had also to be closed for some time due to damage to the infrastructure. The macroseismic survey carried out by the Geological Survey of India in an area as large as 1.2 million sq km indicated the epicentral intensity as X on the MSK scale, that occupied an area of 780 sq km. Apart from damage to civil structures, the 26 January earthquake induced conspicuous terrain deformation January, 2011 in the form of liquefaction features, structural ground deformation and low order slope failures that were mainly prevalent within the higher intensity isoseists. Liquefaction occurred in an area of about 50,000 sq km. The extensive plains of Rann of Kachchh, the marshy tracts of Little Rann and the shallow groundwater table zones of Banni Land provided the most conducive geotechnical environments for the development of seismites. The liquefaction activity was profuse in seismic intensity zones X and IX, widespread in intensity VIII, subdued in intensity VII and stray in intensity VI. The common forms were sand blows/boils, ground fissures, craters, lateral spreading and slumping. Ground deformation of tectonic origin was witnessed within the epicentral tract. Such features, though much less subdued in comparison with the 1819 earthquake, occurred along the Kachchh Mainland fault (KMF) and a transverse lineament, referred to as Manfara-Kharoi fault. The manifestations were in the form of fractures, displacement of strata, linear subsidence, upheaval, formation of micro-basins/ micro ridges, ripping off of rock surface and, at places, violent forms of liquefaction. The localities, where the coseismic deformational features were studied by the author included Bodhormora, Sikra, Vondh, Chobari, Manfara and Kharoi. The studies and documentation of 2001 Bhuj earthquake has brought to light many significant aspects that may contribute to the understanding of 1

32 the seismotectonic behaviour and seismic hazard potential of the dynamic landmass of Kachchh apart from providing an insight into the science of earthquakes. The event has demonstrated in no uncertain terms the role of local geology in influencing the ground motion characteristics and, therefore, the hazard estimation. The devastation caused by the earthquake has sent a strong message across various sections of the stakeholders that there is an urgent need to comprehend the seismic behavior of various tectonic domains of India and formulate mitigation plans in accordance. S1_Keynote-2 Delineation of crustal and lithospheric structure below the Kachchh rift zone: A probable model for the generation of aftershock activity for last 10 years Prantik Mandal (National Geophysical Research Institute (CSIR), Hyderabad , India, Large intraplate continental earthquakes like the New Madrid (Mw 8.0) and the 2001 Bhuj (Mw7.7) were highly destructive because they occurred in strong crust, but the mechanisms underlying their seismogenesis are not understood. Here we show, using local earthquake velocity tomography, and inversion of P-receiver functions that the crust and uppermost mantle beneath the 2001 Bhuj earthquake region of western India is far more complex than hitherto known through previous studies. A new image of the crust and underlying mantle lithosphere indicates the presence of a 18- km thick high velocity (Vp: km/s) differentiated crustal and mantle magmatic layer above a hot and thin lithosphere (only 70 km) in the epicentral region of 2001 Bhuj earthquake. This magmatic layer begins at the depth of 24 km and continues down to 42 km depth. Below this region, brittle-ductile transition reaches as deep as the Moho (~34 km) due to the possible presence of olivine rich mafic magma. Our 1-D velocity structure reveals a basaltic magmatic eclogitic layer at sub-lithospheric levels. This study also delineates an updoming of Moho (~ 3-7 km) as well as asthenosphere (~ 6-12 km) below the Kachchh rift zone relative to surrounding areas, suggesting the presence of patches of partial melts below the lithosphereasthenosphere boundary. Restructuring of this warm and thin lithosphere may have been caused due to rifting (at 184 and 88 m.y. ago) and tholeiitic and alkalic volcanism related to the Deccan Traps K/T boundary event (at 65 m.y. ago). Recent study of isotopic ratios proposed that the alkalic basalts found in Kachchh are generated from a CO 2 rich lherzolite partial melts in the asthenosphere that ascended along deep lithospheric rift faults into the lithosphere. It appears that such kind of crust-mantle structure, deepening of brittle-ductile transition and a high input of volatiles containing CO 2 emanating from mantle control the generation of aftershock activity in the Kachchh rift zone for last 10 years. S1_Keynote-3 Seismic Source of the 2001 Bhuj Earthquake: A Review of Seismic Tomography, Fractal Dimension and b-value Mapping J R Kayal (Indian School of Mines, Dhanbad , More than 800 aftershocks (M > 2.0) were recorded during the first two months after the January 26, 2001 Bhuj earthquake (Mw 7.7) in western part of the peninsular Indian shield. About 500 aftershocks were relocated by simultaneous inversion using the Local Earthquake Tomography (LET) method (Kayal et al., 2002, GRL). Most of the aftershocks occurred in a V- shaped area of 70 x 35 sq km; the maximum activity was observed at a depth range of km. A bimodal distribution of aftershocks indicated that the main shock rupture propagated both in the upward and downward directions, but the rupture did not reach the surface. 3D-velocity velocity structures imaged two fault zones with lower velocity, and a high velocity structure with higher Vp/Vs at the fault ends, at the main shock source depth. Aftershock trends and fault plane solutions are comparable with these two fault/rupture zones at depth. Using the relocated events, b-value and fractal correlation dimension (Dc) mapping are studied (Das and Kayal, 2010, BSSA, submitted). The surface map of b-value as well as an E-W cross section reveals two distinct NE and NW trending tectonic arms of the V-shape aftershock zone. A N-S cross section, on the other hand, clearly imaged January, 2011

33 the b-values of the known fault zones at depth. The geologically mapped known South Wagad fault shows a distinct lower b-value ( ) zone compared to the much higher value ( ) at the Kutch Mainland fault at depth. The images indicate that the main shock and the aftershocks occurred at the lower b-value zone or highly stressed zone at depth. The fractal dimension Dc also differs (2.77 and 2.64) for the two arms of the aftershock zone. These values as well as the overall Dc value 2.28 for the entire aftershock zone are much higher than normally observed values ( ) in a seismically active area, which implies a fraction 3D structure of the Bhuj earthquake source zone. S1_I1 Impact of the 2001 M 7.7 Bhuj earthquake on hazard estimates in the United States Mark Petersen (U.S. Geological Survey, Golden, CO, USA, The U.S. Geological Survey develops seismic hazard maps for stable-craton and extended-margin regions of the central and eastern U.S. These maps form the basis for building design codes, risk assessments, and public policy decisions. Input parameters for these sources rely on best available science but are controversial due to lack of instrumentallyrecorded strong motion data and recurrence information. For example, the New Madrid region of the central U.S. has experienced historical and prehistorical large earthquakes but the seismic hazard is vigorously debated because the interpretations of the limited data incorporate large uncertainties. In 1811 and 1812 three large-magnitude earthquakes ruptured in the New Madrid zone and caused widespread damage and effects. However, few people lived in the region at this time and a limited number of accounts describe the effects of strong ground shaking. Paleo-liquefaction evidence shows that this region has experienced repeated similar sequences of large earthquakes over the past few thousands of years with a mean recurrence time of about 500 years. However, the rate of future earthquakes is questioned because GPS velocity data over the past decade indicate persistent low strain rates. Moreover, the estimated magnitude of these historical events ranges from 6.8 to 8.0, based primarily on interpretations of intensity data and January, 2011 liquefaction distributions. Hough et al. (2002) and Tuttle et al. (2002) suggest that liquefaction data from the largest earthquake of the sequence are consistent with the Bhuj liquefaction field suggesting a similar magnitude. The Bhuj earthquake is thought by some to be a reasonable analog to the New Madrid earthquakes since that event occurred about 400 km from the plate boundary in an intraplate area characterized by low background seismicity. The Bhuj aftershock distribution extended over an area about 40 km 40 km below the surface (Gahalaut and Burgmann, 2004), a much smaller area than that for typical M 7.7 plate-boundary earthquake. This observation demonstrates that large earthquakes can occur on a relatively short fault segment, similar to previous interpretations of the New Madrid sources. Bhuj aftershocks extend down to 45 km (Mandal et al., 2004), which is deeper than most aftershocks recorded in interplate regions. This observation provides evidence for significant rupture areas required to cause large earthquakes with large stress drop (Singh et al., 2003). In addition, strong ground motions for the Bhuj earthquake from seismoscope data indicate that the seismic waves attenuate slower than those from similar-size plateboundary earthquakes near plate boundaries. This is consistent with intensity data in the central U.S. Hypothesized ground motions are also consistent with ground-motion models developed from synthetic ground motions for cratonic regions. Without the Bhuj earthquake, it would be difficult to predict the characteristics of intraplate earthquakes where large earthquakes are rarely observed. Studies of this event are critical for estimating seismic hazard in low seismicity intraplate regions. S1_I2 Targeting the Future Great Earthquakes: Global Monitoring and the 26 January 2001 Bhuj, India Case. Vladimir G. Kossobokov 1,2 ( Leontina L. Romashkova 1, and Anastasia K. Nekrasova 1 ( 1 International Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, 84/32 Profsoyuznaya Street, Moscow , Russian Federation, 2 Institut de Physique du Globe de Paris, Paris, France.) 3

34 Our understanding of seismic process in terms of non-linear dynamics of a hierarchical system of blocks-and-faults and deterministic chaos, has already led to reproducible intermediate-term middle-range earthquake prediction technique confirmed by statistical testing in the on-going regular forward application started in The analysis of seismic sequences within space-time of long-, intermediate-, and short-term scales evidence consecutive stages of inverse cascading of seismic activity to the great shock and direct cascading of aftershocks. The first may reflect coalescence of instabilities at the approach of a catastrophe, while the second indicates a certain state of readjustments in the system after it. The 26 January 2001 Bhuj (Gujarat, India) great earthquake happened just outside the territories considered in the Global Test of the algorithm M8 (Healy, J. H., V. G. Kossobokov, and J. W. Dewey, A test to evaluate the earthquake prediction algorithm, M8,U.S.Geol.Surv.Open-FileReport92-401;URL /2001am8.html), next to the edge of the circle of investigation, which was in Time of Increased Probability, TIP, for a magnitude M8.0+ event before 2003 diagnosed in the regular 2001a Update (dated January 09, 2001) using the USGS/NEIC Global Hypocenter Database through We present characteristics of spatially distributed seismic flux dynamics within long-, intermediate-, and shortterm scales in advance and after the 26 January 2001 Bhuj earthquake, in particular those measures, which were used for the M8 algorithm diagnosis. S1_I3 Relocation of Aftershocks of the 2001 Bhuj Earthquake Using Temporary Array Data. Jim Mori 1 ( Hiroaki Negishi 2, and Tamao Sato 3 ( 1 Disaster Prevention Research Institute, Kyoto University, 2 National Research Institute for Earth Science and Disaster Prevention., 3 Faculty of Science and Technology, Hirosaki University) We use the aftershock arrival time data that were recorded during February 28 to March 6, 2001, on a temporary array of short-period seismographs, to recalculate aftershock hypocenters. There are a total of over 1400 events (M0.5 to 3.5) with recorded P and S waves on 5 to 6 stations. We try using different techniques, including a three-dimensional velocity inversion and hypodd to investigate the pattern of the aftershock distribution. We also use cross correlation of waveforms to try and improve the accuracy of the arrival times. Since the aftershock distribution is relatively deep (10 to 35 km), it is important to use both P and S waves to obtain an accurate estimate of the hypocenters. The aftershocks are distributed over a relatively small area for an Mw 7.7 earthquake. The inferred small fault area implies a relative high static stress drop of 10 to 20 MPa. The results of the relocations show a clearer image of the fault plane compared to the previous locations that used only a one-dimensional velocity structure. The aftershocks show a plane that dips toward the south, similar to previous results, which is inferred to be the mainshock fault plane. There is still a rather complex pattern to the aftershock distribution that shows a large number of off-fault events. S1_C1 Probabilistic assessment of earthquake hazards using method of moments in the Kuchchh (Gujrat), India region of January 26, 2001 earthquake Jayant N. Tripathi (Department of Earth and Planetary Sciences, University of Allahabad, Allahabad , India, The Kuchchh region of Gujrat is one of the most seismic prone areas of India, which has experienced two large catastrophic intraplate, stable continental earthquakes of magnitude Mw 7.8 & 7.7 in 1819 & 2001, respectively. Several moderate and large earthquakes also occurred in the region during last two centuries. The observed recurrence time between the large earthquakes (magnitude e 6.0), which occurred during last 200 years have been used to estimate the probabilities of occurrence of next earthquake in a specified interval of time for different elapsed times using three probabilistic models, namely, Weibull, Gamma and Lognormal. The parameters of the statistical models have been January, 2011

35 estimated using method of moments (MOM). The estimated cumulative probability reaches 0.8 after about 47 years for all the models while it reaches 0.9 after about 53, 54 and 55 years for Weibull, Gamma and Lognormal model, respectively. The conditional probability reaches 0.5, is in the years , and for the Weibull, Gamma and Lognormal models, respectively, however, it reaches about 0.8 to 0.9 for the time period of 50 to 60 years for all the models. S1_C2 Detection Complex Networks of BHUJ Earthquake (2001) and Aftershocks by Using Self Organizing Neural Networks Mostafa Allameh-Zadeh (Seismology Department, The International Institute of Earthquake Engineering and Seismology, IIEES, 27 Arghavan St. N. Dibajie, Farmanieh, 19531, Tehran, I.R.Iran. This paper focuses on the shapes of clusters of BHUJ earthquake that can be visualized in their network based on distance between two events (the pairs of linked neighbors). The knowledge can be extracted from the number of aftershocks and links in their networks.we find that there is strong correlation in Iranian plate region, and that small earthquakes (Ms>4.5) are very important to the stress transfers. It is demonstrated that the synthetic clustering in space and time of earthquakes is useful for seismic hazard assessment and intermediaterange earthquake forecasting by using Self- Organizing Neural networks. The method has been tested for different cases as training phase. In this mode, the actual output of a neural network is compared to the desired output. The network then adjusts weights, which are usually randomly set to begin with, so that the next iteration, or cycle, will produce a closer match between the desired and the actual output. The learning method tries to minimize the current errors of all processing elements. This global error reduction is created over time by continuously modifying the input weights until acceptable network accuracy is reached. With supervised learning, the artificial neural network must be trained before it becomes useful. Training consists January, 2011 of presenting input and output data to the network. This data is often referred to as the training set. That is, for each input set provided to the system, the corresponding desired output set is provided as well. In most applications, actual data must be used. This training phase can consume a lot of time. In prototype systems, with inadequate processing power, learning can take weeks. This training is considered complete when the neural network reaches a user defined performance level. This level signifies that the network has achieved the desired statistical accuracy as it produces the required outputs for a given sequence of inputs. S1_P1 Ground Deformation and Liquefaction Structures formed due to 2001 Kachchh Earthquake on the Sabarmati River bed near village Motiboru, Ta. Dhandhuka, Dist. Ahmedabad, Gujarat, India. R.D. Shah, N.Y. Bhatt and P.M. Solanki (M.G. Science Institute, Navrangpura, Ahmedabad Sabarmati River is one of the major rivers of Gujarat, originating from the Aravalli mountains and debouching in the Gulf of Khambhat. Motiboru village is situated on the banks of Sabarmati river about 80 km in SSW of Ahmedabad near the Gulf of Khambhat. Earthquake of 6.7 magnitude intensity on Richter scale having epicenter near Bhachau which devastated the entire state and adjacent states also left its effects in form of deformation and liquefaction. These seismic features have occurred along the Sabarmati river bed south of Ahmedabad which have became more distinct near Motiboru village. Here on the river bed and on the bank region in the fields, liquefaction structures were formed during 2001 Kachchh earthquake. The structures were covering an area of about 0.5 km width and 2.5 km length within the riverbed and on the left bank region on east side, near Motiboru village. Ground deformation was observed in form of wide open and displaced elongate ground fissures (lurching) indicating lateral spreading. 5

36 The liquefaction structures formed during the 2001 Kachchh earthquake event were in form of sand blows, sand holes, sand domes, sand and mud dykes and dish structures. The structures are 0.3 m to 1.5 m in diameter and dykes extend up to a distance of >15 m and discontinuously found up to 1.5 km. The structures indicate liquefaction of unconsolidated sediments at comparatively shallow depth. The liquefaction had occurred due to earthquake shocks. Consequent to the earthquake very prominent ground features were produced even at a distance of more than 250 km away from the epicenter. This clearly indicates seismic wave tapping and seismic wave amplification in the southern part of Cambay basin. S1_P2 Seismicity Monitoring of Bhuj Aftershocks Santosh Kumar, Sandeep Aggarwal, Vandana Patel, Kishan Zala and B.K. Rastogi (Institute of Seismological Research, Gandhinagar) Bhuj aftershocks are being monitored by ISR from Aug 2006 with Gujarat State Seismic Network of 50 broadband seismographs (19 connected with VSAT) and 50 strong motion Accelerographs. The detectibility is M1.0 in Kachchh, M2.0 in Saurashtra and M2.5 in other areas. In Kachchh 2401 shocks of M3-3.9, 357 shocks of M4-4.9 and 20 shocks of Me 5.0 have occurred during In this region M5.7 level seismicity continued until mid From mid 2006 there is no shock of Me 5.0, however shocks of M<5.0 are continuously occurring. ISR located 52 shocks of M , 714 shocks of M3-3.9 and 5298 shocks of M<3.0 during Presently more than 2000 shocks per year of Me 0.5 are being recorded from Kachchh and 80% are precisely located. Initially hypocenters are located using Seisan program and local velocity model of Mandal (2004) determined by tomography and then refined with HypoDD. With Seisan horizontal error is less than 1-2 km and vertically less than 2-3 km. With HypoDD accuracy is within few hundred meters. Most of the aftershocks are confined to rupture zone (along the North Wagad Fault) of 2001 Mw7.7 earthquake. In 2001 the earthquakes were confined in an area of 20 km x 20 km. Though seismicity reduced from 2002, there was a spurt of increased activity for the two years period of During this period activity migrated to the Wagad area towards east and Gedi fault to the northeast. The seismicity area increased to roughly 60 km x 70 km during In 2008 Banni Fault, north of KMF become active with Mmax earthquakes. On Banni Fault M4.5 occurred on 28 th October In 2010 shock of Mmax4.1 was located on 11 th August 2010 along North Wagad Fault. All other shocks are of M<4.0. Also in 2006 on Island Belt Fault earthquake of M5.0 occurred on 3 rd Feb January, 2011

37 S2: Intraplate Seismicity Convener : O. P. Mishra THEME The Earth s most seismically active regions and sites of its largest earthquakes coincide with the boundaries between the tectonic plates. However, the vast majority of the earth s surface and continents lie within the interiors of these tectonic plates, and intraplate regions can also exhibit significant earthquake activity. Despite advent of modern seismological research, the seismogenesis in the intraplate regions of the world, including Stable Continental Region (SCR) of India is still a great puzzle for geoscientists to explore the plausible mechanism involved into intraplate seismicity. The identity and characteristics of their seismic sources remain unknown. The explanation for the intraplate seismicity necessitates understanding of the evolution, structures and processes of the shield area. Several sets of hypotheses and theories without common consensus on genesis of inpraplate seismicity have been developed and put forth by different researchers for different intraplate regions of the globe (e.g., Africa, Asia, Australia, Europe North America and South America). Moreover, the frequent occurrences of the 1993 Latur Killari (Mw 6.3), the 1997 Jablapur (Mw 6.0), and the 2001 Bhuj (Mw 7.6), Indian earthquakes beneath the intraplate stable continental regions of the Peninsular India ushered a new era of integrated seismological research coupled with multi-disciplinary geo-scientific observations to address the physics of intraplate seismicity. The focus of this session on Intraplate Seismicity is to understand the nature of intraplate seismicity and the forces driving it in the stable continental regions of the world in general, and in peninsular India in particular. Considering significant advances on intraplate seismicity research in recent years, the session on intraplate seismicity invites case studies on recent significance earthquakes and swarm activity in the peninsular India and the regions of analogous geotectonic settings, elsewhere in the world. Presentations on seismotectonic processes, crustal 1-D and 2-D velocity and attenuation models, and studies of regional and local stress patterns with integrated seismo-geophysical interpretation frame work derived from multi parametric seismo-geophysical observatories are also invited. In addition, contributions on ground motion observations from intraplate earthquakes and efforts to model sub-surface seismogenic layers using local and regional 3-D velocity and attenuation tomography are also welcome. S2_Keynote-1 Seismotectonics of Bhuj Earthquake of 2001 based on Gravity and Magnetic signatures- A Near Plate Boundary Earthquake and its Comparison to New Madrid Seismic Zone, USA and Shillong Plateau, India D.C. Mishra (National Geophysical Research Institute (CSIR), Hyderabad Phone: ; Fax: ) Kutch is a Mesozoic rift basin where Jurassic and Cretaceous sediments are exposed. The two major tectonic events that have affected this section is the January, 2011 break up of Africa and Seychelles due to Karoo and Deccan trap volcanic, respectively. Though, there are no exposures of Karoo volcanics in India but it might be overlain by Deccan trap that was quite wide spread. However, in Lodhika parametric well for oil exploration in Saurastra, a second level of volcanic rock below Deccan trap has been reported. Jurassic rift basin of Kutch might have formed due to extension caused by Karoo volcanics as both are contemporary. Subsequently, it was uplifted during closing phase of the basin that resulted into various uplifted blocks such as Kutch Mainland Uplift (KMU), Wagad Uplift (WU) etc. These uplifts might have been accentuated due to Karoo intrusive in the basement during closing phase of the basin that gives 7

38 rise gravity highs over them in spite of thick sediments of low density in these sections. The gravity field of the Kutch suggests an over compensated crust causing present day uplift of the KMU and WU. Coupled with the plate tectonic forces in direction of the plate motion, it has resulted in to consistently rising basement towards north along reverse faults that are seismogenic. Airborne magnetic map of this region shows two sets of long linear magnetic anomalies indicating mafic intrusive that intersect in the epicentral area of the Bhuj earthquake. Circular/ semicircular gravity anomalies of Pachham, Khadir and Bela uplifts indicate plug type intrusive for them. Lineament map of Pakistan suggest that some of them extend from Kutch to the western boundary of the Indian plate. These observations suggest following factors for enhanced and large magnitude earthquakes in this region inspite of being in stable continental regions. i. Over compensated crust causing uplift coupled with present day plate tectonic forces causing northwards uplift of the basement along various reverse faults ii. Large scale magmatism weakening the crustal fabric. iii. Lineaments/structural trends extending to the western boundary of the Indian plate that is a transform fault known as Chamman fault. The last point indicates that the Bhuj earthquake can not be considered purely Stable Continental Region (SCR) earthquake and can be termed as Near Plate Boundary or Diffused Plate Boundary earthquake. Other sections in stable continental region that have experienced large number and magnitude of seismic activity are New Madrid Seismic Zone in USA and Shillong Plateau, India. Similarities between them are presented in course of the presentation during the workshop. S2_I1 Geodynamics of the Kachchh Basin: Gravity- Magnetic Perspective D.V. Chandrasekhar and B. Singh ( National Geophysical Research Institute (CSIR), Hyderabad ) Gravity and magnetic data of the Kachchh basin and adjoining regions have delineated major E-W and NW-SE trending lineaments and faults, some of that even extend up to plate boundaries at north Arabian Sea and western boundary of the Indian plate. The imbricate fault system due to Bhuj 2001 earthquake was clearly deciphered by the detailed gravity and magnetic anomaly map of Kachchh which is different than the Kachchh Mainland Fault (KMF). Bouguer anomaly map depicts that the epicentral zone of Bhuj earthquake is located over the junction of Rann of Kachchh and median uplifts viz. Kachchh mainland and Wagad uplifts, which are separated by thrust faults. Modeling of gravity and magnetic data with constraints from seismic studies suggest that the basement is uplifted towards the north across thrust faults dipping o south. A south dipping (50-60 o ) basement contact separates blocks of high susceptibility / high density under the northern part of the Wagad uplift ( E-W oriented North Wagad thrust fault (NWF) ) exactly coincides with the fault plane of the Bhuj earthquake as inferred from seismological studies. A circular gravity high over the Wagad uplift suggests a plug type mafic intrusive in this region and several such gravity anomalies are observed over the island belt which is analogous to the gabboric intrusion along the Commerce geophysical lineament of the New Madrid seismic zone. The contacts of these intrusive with the country rock demarcate shallow crustal inhomogeneities, a region of possible stress concentrator and excellent site for the accumulation of regional stresses. A regional gravity anomaly map based on the concept of isostasy presents large wavelength gravity lows of about -13 mgal in the epicentral region. Their best-fit model suggest the presence of two centers of mass deficiency representing thick crustal root of 7-8 km (deep crustal inhomogeneity) for a standard density contrast of -400 kg/m 3 which could be intimately related to seismicity in Kachchh similar to Missori gravity low in the case of New Madrid seismic zone. Soon after the Bhuj earthquake repeat gravity and elevation measurement were carried out to find any crustal deformation. Height and gravity measurements observed along a profile across the epicentral area before and after the January 26, 2001, M w 7.6 Bhuj earthquake show a maximum uplift of ± 0.46 m and a gravity decrease of 393 ± January, 2011

39 μgal. A best-fit, single dislocation model of the Bhuj earthquake rupture inverted from the height-change observations using non-linear optimization methods indicates that the high-slip rupture was well contained in the aftershock zone and likely did not break to depths shallower than ~10 km. The earthquake source parameters arrived in the present study agrees well with those provided by fault plane solutions, teleseismic finite-slip inversions and the distribution of aftershocks. The gravity data over the epicentral area are well modeled by the preferred model; however, a strong influence of shallow hydrological processes on the observed changes is inferred for three sites located on the Banni plains to the west, wherein the mean gravity change of +275 μgal suggests a total mass redistribution of as much as 2.9 Mt. In view of above it is inferred that significant amount of stresses gets accumulated in this region due to presence of (a) thick crustal root (b) stresses at the periphery of mafic intrusive, and (c) regional stresses due to plate tectonic forces. S2_C1 Geodetic crustal strain patterns over the Satpura Mountain Belt: Implications for the tectonic controls of stable continental interior seismicity S. Mohanty (Department of Applied Geology, Indian School of Mines, Dhanbad , India The Satpura Mountain Belt forms an ENE WSW trending zone in the central part of India. This Mountain belt located in the Indian plate interior is an ancient orogenic belt of Precambrian age. It has high seismicity in the present time. The crustal strain rates were determined from the changes in positions of geodetic triangulation points in selected areas of the Satpura Mountains during last 87 years and 130 years. A maximum extension rate of +600 X 10-9 year -1 towards N152 -N332 and maximum shortening rate of -317 X 10-9 year -1 along N028 -N208 were determined from the studied areas. The strain rates are comparable to the average strain rates of the continental rift-systems. Detailed analysis of the spatial variations of the strain rates establishes the relationship between the high-strain areas with the regional movement patterns across the Satpura Mountains. The crustal strain determined from the GPS data of the sites in Peninsular India corroborates the strain rates from the GTS monuments. The long distance sites located across the Satpura Mountains show very low amount of NS shortening ( 1.1 X 10-9 year - 1 ), and moderate amount of EW extension (+4.9 X 10-9 year -1 ). However, a detailed analysis brings out local details. The regions south of the Satpura Mountains show very low amount of NS shortening ( 1.7 X 10-9 year -1 ) and moderate EW extension (+3.7 X 10-9 year -1 ). The Satpura Mountain belt has moderate shortening rate in NS direction ( 2.0 X 10-9 year -1 ) and moderate extension rate in EW direction (+3.2 X 10-9 year -1 ). The region north of the Satpura Mountains shows moderate extension rate along NS direction (+6.6 X 10-9 year -1 ) and high EW extension (+10 X 10-9 year -1 ). Moderate shear strain rates are determined from all the sectors of the analyzed region (3.7 to 6.0 X 10-9 year -1 ). The regional variations in the pattern of the crustal strains across the Satpura Mountains is interpreted to be the result of obliquity of the ancient mountain belt with respect to the plate motion of the Indian plate. This obliquity is responsible for partitioning of strain regime to normal and shear stresses across the Satpura Mountains. The curvilinear trend of the belt is expected to give rise to local transpression and transtension for regional seismicity of the central India. Similar mechanisms may be in operation in other zones of high seismicity in stable continental interiors. S2_C2 Mafic Crust and Earthquake Activity in the High Velocity Indian Shield O.P. Pandey (National Geophysical Research Institute, Uppal Road, Hyderabad , India. Dynamic Indian subcontinent with active history of rifting and multiple plume interactions is considered unique among stable areas of the Earth. It contains several rift valleys and mega lineaments which have been repeatedly rejuvenated since at least 1.5 Ga. Continued reactivation / rifting over such a long period of time is hardly seen elsewhere. It is therefore, not surprising that the Indian stable continental region has been frequently experiencing January,

40 moderate seismic activity since a long time, which includes 14 events of magnitude 5 or more in the last 50 years. Many of these earthquakes were destructive in nature leading to heavy loss of human life and property, like Anjar (Mw 6,1956), Koyna (Mw 6.3,1967), Latur (Mw 6.3,1993) and Bhuj (Mw 7.7,2001) etc. The last two events alone claimed more than 30,000 human lives. Inspite of large number of studies, cause of recurring seismic activity still remains a subject of considerable debate. Our detailed study of important earthquake localities indicates quite high P- and S- wave velocities ( km/s and km/s respectively) at a shallow depth of almost surface to six kilometers. These seismogenic regions appear to be in a state of continuous uplift and erosion since geological times, which led to shallow surfacing of mafic (amphibolitic-granulitic) crust in which stresses tend to accumulate due to ongoing local upliftment and a high input of heat flow from the mantle. These stresses are apparently acting over and above to the regional compressive stresses generated by India- Eurasia collision. S2_C3 An Intraplate Earthquake and the study of Ground Response Analysis using Equivalent Linear Method -a case study of NCT Delhi. H.S.Mandal (Earthquake Risk Evaluation Centre, India Meteorological Department, New Delhi, E- Amplitude of earthquake ground motion is affected by both the properties and configuration of the near surface material through which seismic waves propagate. The study of earthquake responses i.e. evaluation of peak frequency and frequency dependent amplification of a site is very important parameter from engineering aspect to formulate seismic code to construct earthquake resistance structures. The peak frequency and amplification varies from place to place due to the variable soil properties and thickness, which reveals in the special variation of damage pattern observed in a city during the big earthquake. This is basically non linearity of the soil underlining below the structure. The study of non linear behavior of the soil deals the way of the stress-strain changes of the material due to certain initial exerted stresses. The characteristic of normalized shear modulus (G/G 0 ) and damping (h) also changes accordingly with increase of strain. The numerous studies reveal that the non-linear behaviors occurred only the alluvium deposit sites. The Silt, Sand, silt-sand, Sandy-silt, Clay material are example of earthquake hazardous type of soils. The archeological survey reveals that the Yamuna has changed its course during last several hundred years and migrated eastward keeping flood plains in the left. The Delhi, National Capital of India now extends over swamps and recent fluvial deposits on the banks of the River Yamuna. Apart from the flood plain area a vertical ridge which is passing along the SSW to NNE direction in the center part of the NCT Delhi. The ridge is exposed at some places with characteristics of weathered rock at the surface. The identification of this complex geological variation and bed rock depth is essential for precise determination of soil responses. In this paper an attempt has been made to find out the soil response parameters over few places of NCT Delhi. The prerequisite of the study are (i) the input earthquake motion at the rock level and (ii) the soil column information just above the rock level at different sites. An intraplate earthquake of magnitude 4.3 in Richter scale, occurred on November 25, 2007 at Delhi- Haryana Broader region (lat N, long E and focal depth 20.3km) and Acceleration time history recorded at Ridge observatory of India Meteorological department which is about 20km far from the earthquake source has been considered for this study. This observed acceleration time history taken as a key input for soil response studies. The exploratory drilling undertaken by various agencies has brought out the subsurface configuration of rock formation and depth to bedrock in different parts of Delhi region. The nature of bedrock topography is rendered uneven due to the existence of subsurface ridges. Thickness of alluvium overlying the quartzites increases away from the outcrops. In the city block, west of the ridge, the alluvium thickness increases away from the ridge to 300 m or more. East of the ridge, in the area up to River Yamuna, the alluvium thickness is comparatively less to about 165 m. East of the River Yamuna covering parts of the city and Shahdara blocks, the thickness ranges January, 2011

41 from 48 to 240 m. This information has been used to determine soil column information up to different depth as a second parameter of the study. The soil column is demarcated by few layers with depth depending upon the thickness of the soil. The each layer material properties are defined as density, shear wave velocity (V s ), shear modulus (G) and damping (h) as input parameter. The soil responses are evaluated at every one km interval along two profiles (i) north-south direction i.e. from ISBT (Inter State Bus terminal) to Sewanagar and (ii) east-west direction from Tilak Bridge to Punjabi Bagh. The close intervals are taken to check the soil amplification or de-amplification criteria along the profile with variable soil depth. The Equivalent Linear Method (ELM) is applied to find the earthquake response at the level ground surface. The yielded peak frequency from the amplification spectra at the ground surface and the Fourier response spectra of the input signal are compared and agreed well with each other. The peak amplification varies from 4.2 to 5.9 and corresponding peak resonance frequency varies from1.2 to 5.3Hz. The more value of peak amplification factor is found at thicker alluvium deposit site with less frequency contains ground motion and vice versa. Key words: Equivalent Linear Method, amplification, peak frequency, base rock, soil model, SMA, Intraplate earthquake. S2_C4 Study of the Shallow Seismic Activity Offshore Southern and Eastern Sri Lanka Shantha S.N. Gamage and S.A.D.L.K. Suraweera (Department of Physics, University of Sri Jayewardenepura, Sri Lanka) Sri Lanka is considered to be in an aseismic zone away from major plate boundaries or any active faults. However during the last century, there have been several hundreds of earthquakes and earth tremors reported in and around Sri Lanka. Some of these events are described in historical records and more recent events have been identified by institutions such as United States Geological Survey (USGS), and other global seismic networks. These earthquakes have been categorized as shallow and intermediate depth earthquakes. Although this type January, 2011 of earthquakes have been occurring specially in the offshore region of Sri Lanka, detailed investigation of their activity in this region has not been carried out. We therefore made an attempt to investigate earthquake activity of offshore region of the eastern and southern Sri Lanka which is seismically active. We analyzed the shallow seismic activity of offshore of eastern and southern parts of Sri Lanka and identified their focal mechanisms. We obtained hypocentral data from the Data Management Center (DMC) at the Incorporated Research Institutions for Seismology (IRIS). The earthquake list distributed by the IRIS DMC made clear that there are sometimes multiple epicenter estimates for a single earthquake. We identified those errors and calculated them relative to the NEIC catalog epicenter. Since there are mislocations of events, we tried to identify the magnitude of those errors. Then we analyzed the seismic activity region by region. Our finding shows that large number of earthquakes takes place at a belt lie in southern part of offshore Sri Lanka although some events are scattered due to location errors mentioned above. The focal mechanism data obtained from Harvard CMT moment tensor catalogue were also analyzed for the events occurring in the region. Although different types of focal mechanism solutions exist in earthquakes of near coast events, we clearly noted that earthquake belt in the southern part of Sri Lanka have mechanical solutions which is similar to that of strike slip fault mechanisms. It seems that this seismically active region may belong to the boundary of Indo-Australia plate. S2_C5 Assessing the intraplate type generation of subduction zone mega-thrust earthquake with special reference to 2004 Sumatra event M W 9.3 Prosanta K. Khan (Department of Applied Geophysics, Indian School of Mines, Dhanbad , India, Subduction zone mega-earthquakes are traditionally thought to be caused by sudden stress-relieving displacements at the contact zone locked asperities (topographic highs/seamounts) between the descending oceanic lithosphere and the overriding continental plate. Assessment of such six 11

42 earthquakes viz off Sumatra, 1965 Rat Islands, 1964 Alaska, 1960 Chile, 1957 Aleutians, 1952 Kamchatka, however, reveals that the relationship between interplate coupling and seamount subduction is rather ambiguous as estimated χ values vary widely. Further, the best ever recorded 2004 Sumatra event argues the stationary model of asperity subduction along the Sunda margin. With this background the 2004 Sumatra mega-event was studied considering rheology and geometry as well as the penetration of the slab through the mantle. The present study proposes an intraplate model for mega-thrust earthquakes with failure of the subducting oceanic slab, and suggests the flexing zone of the descending lithosphere as the nodal area for major stress accumulation. We believe that at high confining pressure and elevated temperature, unidirectional cyclic compressive stress (arises due to unbalanced component of slab resistive force) loading in the flexing zone results an increase of material yield strength through strain hardening, which transforms the rheology of the layer from semi-brittle to near-brittle state. The increased compressive stress field coupled with upward migration of the neutral surface under non-coaxial deformation triggered shear crack on 26 th December 2004 preferably at the rheological interface between strain-hardened near-brittle layer and deformed ductile layer within the sub-oceanic mantle. The subsequent growth of the shear crack was initially confined in the near-brittle domain, and propagated later through the more brittle crustal part of the descending oceanic lithosphere in form of cataclastic failure. This study warrants for an assessment of failure during large earthquakes within the continent, normally originated at depths between 10 and 25 km, and likely associated with the shallower strong elastic core of the lithosphere. S2_C6 Crustal Strain Pattern over a part of Southern India and its implication for Seismotectonics. Arijit Barik and S. Mohanty (Department of Applied Geology, Indian School of Mines, Dhanbad , India) The Indian Peninsula, in general and its southern part in particular, is considered to be a stable shield area. There is growing evidence that the Indian peninsular shield is no longer a continental interior of low seismic activity. The present study was carried out to determine the relation between the strain rates over a part of South India and to identify possible vulnerable areas to earthquake devastation. Computation of the lithospheric plate velocity field data for the South Indian Block has shown that there is a significant amount of extensional strain along the EW direction whereas the NS direction has negligible amount of shortening strain. The comparative results of strain data for a number of computation models and reference frames used in the analysis show that the shear strain values in all the models are high and are comparable to those of the continental rift system. These analyses suggest that the deformation of the Indian plate is presently achieved by rotational deformation in anticlockwise direction. Such a strain regime together with the movement of the Indian plate towards NNE to NE is likely to activate the regional faults aligned E-W, NE-SW and NW-SE. So this significant amount of extensional strain component along EW direction is stretching the crust of the Indian Peninsula along EW direction and making the crust weak and earthquake prone. The focal mechanism solutions of some of the recent earthquakes in the region corroborate the computed strain patterns, and the Neotectonic activity expected in this model study. S2_C7 Intermittent Micro-seismic Activity in the Vicinity of Nanded city West Central India Md. Babar Shaikh (Associate Professor, Department of Geology, Gyanopabok College, Parbhani P. O. Box No. 54, Maharashtrta, India. Among the earthquakes of the Deccan Basaltic Province, the Koyna earthquake of 1967 (M 6.3) and Killari earthquake in 1993 (M 6.2) were disastrous in West Central India. Significant Earthquakes followed at Latur-Killari in 2005 and several times at Koyna. The present study area in the vicinity of Nanded City (Maharashtra state) has experienced a series of minor tremors that have been felt since 13 November Based on media reports and on felt reports, activities in this sequence increased notably on 31 March 2007 and reduced by May, picking up once again at the end of October continuing up to January The January, 2011

43 strongest events were felt on 31 March 2007, then on 12 November 2007 and 14 December 2007 causing widespread panic. The micro-seismic activity ended by January Over 500 events have been felt since late 2006 to January Again the microseismic activity started in the month of October 2010 with maximum felt event on 21 st November 2010 at pm (M W 2.4). The tremors are associated with subterranean explosive sounds. The residents in northern parts of Nanded town that has been hit by the tremors moved to safer areas or were staying outdoors in temporarily erected shacks in front of their houses during the activity periods. The max.-magnitude earthquake made widespread minor cracks of houses around the epicentral area in the Nanded city. The shocks are mostly confined to North and Northwest of Godavari River. The spatial distribution of the local micro-seismicity of events suggests that the NW-SE structure may be a potential seismogenic structure. About 69 tremors that occurred during the months of November and December 2007 have been located by 4 Broadband seismic stations in the epicentral region and their locations coincide with the reported region of maximum ground shaking. Majority of the epicentres lie in an area of 12.5 sq. km (5kmX2.5 km) between the Asna and Godavari Rivers and the depth extent of this activity is limited to the top 3 km. The NW-SE trend of the Asna River coincides with the trend of the seismic activity indicating that the river course is being guided by a NW-SE trending lineament. More over there is report of historical 1942 earthquake of Mw 4.2 north of Nanded city. S2_C8 Structural controls on the intraplate seismicity of the Kachchh region, India Sushmita Sinha ( and S. Mohanty (Department of Applied Geology, Indian School of Mines, Dhanbad , India.) The Kachchh province of Western India is a major seismic domain in an intraplate setup. The seismic zone is located in a rift basin, which developed during the early Jurassic break-up of the Gondwanaland. The neotectonic activity of the region is attributed to January, 2011 the basin inversion phase. Detailed analysis of the fault patterns and crustal strain were carried out to determine the tectonic controls on the seismicity of the Kachchh region. The regional faults of the study area have EW strikes, giving rise to highlands extending in EW direction. These high areas are affected by several transverse faults with NE-SW and NW-SE strikes. Crustal strain determined from the GPS velocity data of post-seismic time period following 2001 Bhuj earthquake, indicates a maximum strain rate of 300 X 10-9 /yr along N013. Focal mechanism solutions of the main event of 26 January 2001 and post-seismic events show the maximum principal stress axis close to this direction. Maximum shear strain rate determined from the GPS data of the area has similar orientation. The unusually high strain rate is comparable in magnitude to the continental rift systems. The model velocity data for the region corroborates the high strain regime of the study area (17.24 x /yr). However, the model strain rate is relatively of low magnitude because of very long duration value taken for plate rotation parameters. The orientation of the principal stress axes of focal mechanism solution data and the strain determined from the GPS velocity field do not match with the plate velocity vectors of the Indian plate (46 towards N047 ). This is interpreted to be the result of partitioning of deformation into the strike slip components parallel to the regional EW faults and the normal component perpendicular to the regional faults. The transverse faults parallel to the anti-riedel shear planes have become critical under these conditions. These anti-riedel planes are interpreted to be critical for the seismicity of the Kachchh region. S2_C9 Improved Seismicity Trends in the Koyna- Warna Region through Earthquake Relocation using hypodd. G. Srijayanthi Pinki Hazarika, M. Ravi kumar, D. Srinagesh and N. Purnachandra Rao (National Geophysical Research Institute (Council of Scientific and Industrial Research), Uppal Road, Hyderabad ) The earthquake of M6.3 in 1967 near Koyna tops the list of earthquakes triggered by reservoir, for the 13

44 largest and most damaging earthquake. This area located on the South Western part of Deccan Volcanic Province called Koyna-Warna seismic zone is prominently known for its sustained seismic activity since four decades. A network of 12 stations spanning a 20y!30 km area in the Koyna-Warna Region (KWR) is operated by National Geophysical Research Institute, to monitor the activity. Hypocentres of earthquakes recorded from February 2006 to December 2009 were located, using HYPOCENTRE program. To understand tectonic processes, earthquake recurrence, and earthquake interaction, a thorough analysis of seismicity and a very good understanding of the spatial trends is essential. Especially the active faults can be readily identified using microseismic distribution. Thus, to refine hypocentral locations, hypodd, a double-difference approach for hypocentre locations is used, by which the rms (root mean square) error has been brought to an optimum level of 0.01 and errors in location, depth are limited to < 100 m. The new improved locations show clear trends of seismicity with focused clustering, as compared to single event locations. Especially, the focal depth accuracies are improved, with minimum dependence on velocity models resulting in better constrained fault geometries. S2_P1 Spatiotemporal Complexity of Intraplate Seismicity: a Reverie and its Multifarious Implications Arjun Tiwari (Final Year, M.Sc.Tech (Applied Geophysics) Indian School of Mines Dhanbad, E- mail Unlike at plate boundaries, where plate motions give insight into why and how often earthquakes occur, we have little idea of what causes intraplate earthquakes, and no direct way to estimate how often they should occur. As a result, progress in understandings these earthquakes is much slower than for earthquakes on plate boundaries, and key issues may not be resolved for very long time. Hence, the distribution of earthquakes in space and time within continental interiors is far more complex than on major plate boundary faults. Here situation is quite different within continental plate interiors, where earthquakes appear to be clustered, episodic, and migrating in space. Continental intraplate seismicity provides one of our few ways of studying the limits of plate rigidity and intraplate stresses, and poses the challenge of deciding the appropriate level of earthquake preparedness for rare, but potentially destructive, earthquakes. Moreover, we analyze the spatiotemporal exemplar of intraplate seismicity using a finite element model. The model assumes tectonic loading, crustal failure and stress evolution. Here, we start with a simple model with horizontally homogeneous crust and then we consider timescaledependent spatiotemporal exemplar of seismicity, effects of weak zones and fault weakening. The complex variation of seismicity in space and time poses a major challenge for seismic hazard estimation. These exemplars of intraplate seismicity indicate that earthquake hazard assessment based on few historic records may be inclined towards overestimation as well as underestimation. S2_P2 Unusually large number of earthquake sequences in Saurashtra since 2006 due to stress pulse of 2001 M7.7 Bhuj earthquake. B.K. Rastogi, Santosh Kumar and Sandeep Aggarwal (Institute of Seismological Research, Gandhinagar ) After 2006, earthquakes of M3.0 to 5.0 with long sequences of foreshocks and aftershocks have started occurring in Saurashtra region of Gujarat state at a number of places along small faults. These places are Sayla in Surendernagar district, Talala in Junagadh district, Adwana in Porbandhar and Khankotda, Kalavad, Sanala and Moti Khavdi area in Jamnagar districts. Shocks have recurred every year since 2006 in Jamnagar district, since 2007 in Talala, Junagarh district and since 2008 in Surendernagar district. These sequences occurred mostly during September to November after heavy rains. These shocks are felt with subterranean sounds and have depths of near surface to 8.0 km. Earthquakes of M4.8 and M5.0 which occurred in Nov 2007 in Talala and M4.0 in Kalavad in September 2006 caused damaged to number of houses. The activity of these areas was monitored by deploying January, 2011

45 local Broadband seismograph (BBS) networks. The areal extent of the epicenters is 2 to 30 km. In 2000, Bhavnagar experienced damaging earthquake of M4.2 and several earthquakes associated with long sequence. The seismicity in Saurashtra, during the current decade is higher than as compared to last 20 decades (barring the year 1938 when damaging earthquake of M> 5.0 occurred in Paliad, south of current activity in Sayla). The unusual seismicity in Saurashtra since 2006 is suggested to be due to stress increase by delayed stress pulse transmitted by viscoelastic process from 2001 Bhuj M7.7 hypocenter up to 200km distance in the south. The sudden rise of water table by 30 m from pre to post monsoon is inferred to cause 3 bars stress change which triggers small to moderate earthquakes. S2_P3 New insight into crustal heterogeneity beneath the 2001 Bhuj earthquake region of Northwest India and its implications for rupture initiations. A.P.Singh 1 O.P.Mishra 2 B.K. Rastogi 1 ( 1 Institute of Seismological Research (ISR), Raisan, Gandhinagar , Gujarat. 2 Geological Survey of India, 27, J. L. Nehru Road, Kolkata and SAARC Disaster Management Centre, New Delhi The seismic characteristics of the 2001 Bhuj earthquake (Mw 7.6) has been examined from the proxy indicators, relative size distribution (3D b-value mapping) and seismic tomography using a new data set to understand the role of crustal heterogeneities in rupture initiations of the 2001 Bhuj earthquake of the Kachchh, Gujarat (India), one of the disastrous Indian earthquakes of the new millennium. The aftershocks sequence of 2001 earthquake recorded by 22 seismograph stations of Gujarat Seismic Network (GSNet) during the period from 2006 to 2009, encompassing approximately 80 km X 70 km rupture area had revealed clustering of aftershocks at depth of 5 35 km, which is seismogenic layer responsible for the occurrence of continued aftershocks activity in the study region. The 3D b- value mapping estimated from a total of 3,850 precisely located aftershocks with magnitude of completeness Mc e 2.7 which shows that a high b- value region is sandwiched within the main shock hypocenter at the depth of km and low b-value region at above and below of the 2001 Bhuj main shock hypocenter. Estimates of 3-D seismic velocity (Vp; Vs) and Poisson s ratio (á) structure beneath the region demonstrated a very close correspondence with the b-value mapping that supports the similar physio-chemical processes of retaining fluids within the fractured rock matrix beneath the 2001 Bhuj mainshock hypocenter. The overall b-value is estimated close to 1.0 which reveals that seismogenesis is related to crustal heterogeneity, which is supported by low-vs and high- á structures. The high b-value and high-á anomaly at the depth of km indicate the presence of highly fractured heterogeneous rock matrix with fluid intrusions into it at deeper depth beneath the main shock hypocenter region. Low b-value and high-vp in the region is observed towards the north-east and north-west of the main shock which might be an indication of the existence of relatively competent rock masses with the fractured, overpressure gas-bearing formation and excludes the presence of the molten rocks January,

46 S3: Seismicity and Earthquake Parameters Conveners : J. R. Kayal and Prantik Mandal THEME The essence of seismology lies in the observation and interpretation of earthquakes in terms of seismicity, seismological characteristics, source parameters and the source processes. There is a continuing need to improve knowledge on the intra-plate as well as on the inter-plate seismicity. The information that are extracted from seismograms need to be reviewed and expanded so as to provide the best possible analysis and interpretation. Thus methods for seismological interpretation need to make an account of the Earth complexities, development of seismic modeling and intensive computation that has benefited greatly from advances in computer technology. Most earthquakes in continental areas require an understanding of the distribution of seismicity and faults beyond; how the structural and tectonic setting condition earthquakes of various kinds of geologic, geophysical and seismologic phenomena. Contributions are invited for all aspects of the collection, analysis and interpretation of seismological data in intra-plate and inter-plate seismic environments including: 1. Developments in seismic networks and data centers-including land, ocean-bottom and planetary networks, international data exchange, management of massive data sets. 2. Comprehensive seismogram analysis at single stations, seismic networks and arrays, potentials and future developments. 3. Rapid and routine determination of earthquake parameters including location and source parameters, fault-plane solutions, seismic characteristics like b-value, p- value, fractal dimension etc. 4. Advances in wave propagation in heterogeneous media, including synthetic seismograms and waveform modeling in realistic Earth structures, theory and observations of scattering, attenuation and anisotropy. 5. Developments in seismological interpretation, including development of inversion techniques and seismic tomography. S3_I1 Seismic Hazard Assessment for Karachi, Pakistan 1 MonaLisa ( and 2 M. Qasim Jan ( 1 Department of Earth Sciences, Quaid-i-Azam University, Islamabad, Pakistan. 2 National Centre of Excellence in Geology, University of Peshawar, Peshawar, Pakistan.) National Centre of Excellence in Geology, University of Peshawar, Peshawar, Pakistan Seismic Hazard Assessment (SHA) for the site of Karachi, using deterministic approach, has been carried out. Additional information in the form of earthquake catalogue, delineation of active faults within 50 km of Karachi, their relationship to the seismicity and focal mechanisms and the establishment of seismotectonics zones have been undertaken. Due to the incomplete and short history of both documented and instrumental earthquake distribution, no clear pattern of seismicity has been observed. A distinct clustering of events, however, has been noted in the west of Karachi, in the Makran subduction zone. Majority of the earthquakes range in magnitude from M w 4.0 to 5.0, but the 1945 Makran earthquake that occurred about 250 km west of Karachi measured M w 8.1. Prominent seismic activity is concentrated in the north and NW of the Karachi city January, 2011

47 Delineation of active faults through geological field studies and focal mechanism studies (M w ³ 4 earthquakes) indicate three active seismotectnics zones around Karachi. These are: Zone 1 in the south of Karachi, with transtensional features comprising strike-slip and normal faults, Zone 2 in the north of Karachi, with pure strike-slip faults system, and Zone 3 with blind thrusts in the east and west of Karachi. The b-value and maximum potential magnitude have been assigned to these zones. SHA incorporating deterministic approach has been undertaken using two attenuation relationships adopted for Iran and India. The SHA shows higher values for the zone 2 (0.3 g) and 3 (0.32 g). The seismic design parameters, i.e. Operational Basis Earthquake and Maximum Credible Earthquake accelerations, have also been determined. S3_I2 An Overview of the Seismic Activity and Associated Hazards in South-America and the Caribbean: Socio-Economic Impact of Severe Earthquakes in These Regions Omar J. Pérez( Carlos Rodríguez and José L. Alonso (Simon Bolivar University, Dpt. Earth Sciences, Caracas, Venezuela.) Most of the population of western South-American and the Caribbean countries are selectively concentrated along seismic belts that have been the locus of frequent destructive earthquakes in historical and recent times, occasionally accompanied by tsunamis, great landslides and other earthquakeinduced natural phenomena. The ~70 mm/a to ~80 mm/a east-northeast subduction of the Nazca plate beneath the South-American continent has resulted in several of the largest earthquakes with a cumulative death toll exceeding 100,000, hundreds of thousands of people injured and homeless, billions of US dollars in economic losses, and rather commonly wide-spread damage, impacting big cities and towns, industries, public buildings, the educational and health sectors, electrical and power lifelines, commerce and infrastructures of communications, the most recent disaster being that generated by the giant (Mw 8.8) Chilean quake of February The Caribbean plate, slipping easterly at a rate of ~20 mm/a relative to North- and South-America, January, 2011 shows a relatively low seismic productivity with plate boundaries characterized by the occurrence of relatively small (Mw < 8) seismic events. Yet it has generated several lethal earthquakes in historical and recent times, including the 1812 Venezuelan quake during which 8% of the country s population was killed, and more recently the Haiti event of January 2010 that resulted in an estimated death toll of around people and a country practically destroyed by a fairly small (Mw 7.0) seismic event. Most of the population in South-America and the Caribbean is urban, with belts of misery and poverty characterized by poor constructions and facilities surrounding the rich portions of large cities and towns. This increases dramatically the seismic vulnerability of the population and clearly indicates the need of research not only in seismology, tectonics, earthquake engineering and other branches of science including social and economical sciences, but also the need to define and implement responsible Policies of State in each country, including an inter- American system of mutual assistance, designed to mitigate the effects of earthquakes and other natural disasters in society. S3_C1 A study of Source Parameters, Site Amplification Functions and Attenuation Parameter from the Accelerograms of an Earthquake in Delhi Region Manisha, Dinesh Kumar and S.S. Teotia (Department of Geophysics, Kurukshetra University Kurukshetra India.) The Delhi region lies in the geological realm of the Peninsular India (PI) and is about 200 km away from the Himalayan collision zone. However, a great or large earthquake in the Central Seismic Gap (CSG) of Himalaya may cause severe damages in the Delhi region. Further, it has been suggested that within Delhi region, there is a deficit in released seismic strain energy, capable of generating a damaging earthquake (Verma et. al.(1995), J. of Himalayan Geology). The occurrence of such an event in a densely populated city with several old and weak structures such as Delhi can be devastating. The locally recorded accelerograms carry rich information about the source parameters, which may be used for testing models of sources, which in turn may be used for the evaluation of seismic hazard in the region. Such 17

48 data set is, however, limited in the Delhi region. The accelerograms of the 25 th Nov., 2007 earthquake occurred in Delhi (28.6 N, 77.0 E, depth 20 km, magnitude 4.7) recorded at nine sites provide an opportunity to do the source analysis. These accelerograms have been used to estimate the source parameters, site amplification and attenuation parameter. The SH waves are minimally affected by the crustal heterogeneities and correction for mode conversion at the free surface is not required. The source spectra obtained from the accelerograms have been modeled in the terms of Brune Spectra to estimate source parameters (moment, magnitude, stress drop, source dimension) and attenuation parameter Q. The site amplification characteristics have been estimated using the ratios of horizontal and vertical component spectra at various sites. The frequency bands where there was a significant amplification were identified. These amplification bands are related to the ones where a departure of the observed source spectral data from the best-fit Brune source model is observed. We note a significant site amplification (3-4 times) at the site of Maharaja Aggarsain College (MAC) situated on younger alluvium in the trans Yamuna region. For the sites situated in older alluvium (like Guargaon, Rewari, Ballabhgarh) the site amplification levels are lower than MAC. S3_C2 Source Parameters and Scaling Relations for Small Earthquakes in Kumaon Himalaya K. Sivaram and S.S. Rai (National Geophysical Research Institute, Hyderabad India); Dinesh Kumar and S.S. Teotia (Department of Geophysics, Kurukshetra University Kurukshetra India.) The interdependence of various earthquake source parameters like magnitude, moment, fault dimension, stress drop, corner frequency, seismic energy are termed as scaling relations. These scaling relations are required to understand the physics of earthquakes and fault dynamics in a region. These relations also provide the sound basis for estimating the seismic hazard potential in a region. The simulation of earthquake ground motions is required for the proper evaluation of seismic hazard in a region. The amplitudes of simulated time histories are governed by the values of source parameters like stress drop and fault dimensions in addition to other parameters. The scaling relations provide the estimates of these parameters. The use of global scaling relations may not be useful in some regions as the ambient stress conditions and ranges of stress drop may differ from region to region. Therefore the regional scaling laws are required to determine the values of stress drop and fault dimensions. The purpose of the present study is to estimate source parameters and to develop the scaling relations for small earthquakes in the region of Kumaon Himalaya. The study is based on the spectral analysis of 30 earthquakes with magnitude range recorded at broad band instruments in the region. The displacement spectra of P- and S-waves have been analyzed with Brune s ω -2 model. A two step search procedure for determining the optimum values of the parameters is used while estimating the corner frequency using Andrews approach. A misfit function between the fitted Brune spectra and observed spectra has been used in the procedure. The average ratio of the seismic moment from S to P wave is found to be The agreement between the seismic moments estimated from P and S waves shows that the results obtained are reliable. A shift in the corner frequency estimated from P-wave and S-wave has been observed. The scaling relation between seismic moment and stress drop suggests decreasing stress drop with decreasing seismic moment. The results of the present study are expected to be useful for the proper evaluation of seismic hazard in the region. S3_C3 Spatial statistics: A Technique to constrain Earthquake Cluster to Prognosticate Potential Seismic source zones Basab Mukhopadhyay ( Sujit Dasgupta (Deputy Director General (Retd.), Anshuman Acharyya and A. K. Malaviya (Geological Survey of India, 27 J. L. Nehru Road, Kolkata , India) One of the key issues in seismic hazard assessment is to identify earthquake source zones in a socially useful platform with reasonably acceptable spatial attributes, particularly in regions of diffused seismicity January, 2011

49 like those in the Himalayas. Innumerable moderate size earthquakes pop-up all along the length and breadth of the Himalaya along with some damaging large and great earthquakes interspersed both in space and time. From this apparent chaotic spatiotemporal distribution of earthquakes can we bring out some semblance to tag them as segments for strain concentration and subsequent release as earthquakes? And can we then short-list them as past is the key to the future? Implicitly we are vouching for a characteristic earthquake source model but that is what crops out from our study. Identification of earthquake source zones is one of the prime research areas for the earth-scientists and can be approached through different disciplines including geology, seismology, geodesy and statistics. Our discourse is on tackling the issue wherein a simple spatial statistical procedure has been attempted through which the spatial extents of visually identified clusters of epicentral plot can further be constrained. The procedure is a combination of two spatial statistical techniques; near- and point density analysis. Point density is a statistical tool used to identify areas where data points are concentrated more or vice versa. To calculate point density, the distance between the adjacent earthquakes is measured by near analysis and statistically a mean distance is calculated. This radius is used as search radius to calculate area of the circular neighbourhood. Point density is derived as the total number of earthquakes that locate within the circle divided by the area of the neighbourhood. A factor resulting from the size of earthquake is also taken into consideration for deriving the point density value, e.g., 5 points are counted instead of one count for an earthquake of magnitude 5 in the selected neighbourhood. This is done to offer more weight to larger earthquakes. The measurement is then carried out in an overlapping grid pattern both along latitude and longitude of the map area by a sliding distance equivalent to the search radius and calculated value stored at the center of the circle. The resulting grid value has a mean (m) and standard deviation (sd). Areas with higher point density [value > (m + 1sd)] are marked as zones of spatial clusters. Result of this statistical exercise has recently been published (Mukhopadhyay et al., 2010) where 22 spatial seismicity clusters have been demonstrated from the entire Himalaya and adjacent areas utilizing January, 2011 data from 1964 to Additionally the same earthquake catalogue was subjected to temporal analysis through time-distance window technique to bring out 53 temporal clusters consisting of foreshockmainshock-aftershock (FMA), foreshock-mainshock (FM) or mainshock-aftershock (FA) sequence. Curiously enough, these 53 temporal clusters locate within the 22 spatial clusters but at the same time each of these spatial clusters contains more standalone events than the temporal cluster events. Proceeding further as detailed in our recent publication, eight such spatial clusters (A to H: from Kashmir in the west to eastern syntaxis in the east) located within the Lesser Himalaya involving either or both MBT and MCT were short-listed for detailed seismotectonic and seismic hazard studies. Assuming the length of these clusters as possible maximum rupture length, maximum capable magnitudes, Mw varying from 7.7 to 8.4 have been projected. Inducting into the analysis of historical earthquake records, recurrence pattern and other seismogeological attributes it has been prognosticated that Kangra (cluster B), East Nepal (clusters E & F), Garhwal (cluster C) and Kumaun-West Nepal (cluster D), in decreasing order of earthquake threat, are potential source zones for large earthquakes ( Mw 7.7). As a follow up to the above study which was based on earthquake data up to June 2006 we present two add-ons in this paper. Within the area of study during the period July 2006 to May 2010, a total of 49 teleseismic events of magnitude mb 5.0 are recorded by NEIC out of which four are larger with mb earthquakes out of 49 events (85.71%) locate within 12 of the 22 spatial clusters; and out of these 12 clusters, six are among the eight for which detail study have already been presented. The damaging Bhutan earthquake of September 2009 locates within the Bhutan- Bomdila (G) cluster. The other three events locate within spatial clusters in southern Tibet. This significantly adds to the credibility of the mapped spatial clusters. As further refinement, we have probed the dataset through extreme value statistics [Gumbel probability plot], with earthquake data from 1960 to 2010 for some of the clusters. The study is still in progress but preliminary analysis indicates that the expected Mmax for a return period of 50 and 100 years with 19

50 the following results: Kangra cluster (5.7 & 6.0); Garhwal cluster (6.4 & 6.8); Kumaun-West Nepal cluster (6.4 & 6.6); East Nepal clusters: Cluster E (6.4 & 6.8) & Cluster F (6.1 & 6.5); and Bomdila cluster (6.0 & 6.2). These probabilistic estimates based purely on statistics underestimates the earthquake magnitudes derived on the basis of rupture lengths. References: S3_C4 Mukhopadhyay Basab, Acharyya Anshuman and Dasgupta Sujit, (2010), Potential source zones for Himalayan earthquakes: constraints from spatial temporal clusters. Natural Hazards, DOI /s , published online 26 th September Estimation of Seismic Source Parameters in Northeast (NE) India from body wave spectra Alok Kumar Mohapatra ( and William Kumar Mohanty (Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, ) Source parameters are estimated for ten local earthquakes (M ) recorded by a three-station broadband network during April November 2002 in Northeast (NE) India. The source parameters like seismic moment (M 0 ), stress drop (Φ), source radius (r), radiant energy (W o ), and strain drop (Σ) are estimated using displacement amplitude spectrum of body wave using Brune s model. The amplitude spectra of transverse component of the S-waves are corrected for instrument response, path propagation effects (attenuation correction) and effects of the radiation pattern. The estimated seismic moments (M 0 ), range from to dyne-cm. The source radii (r) are confined between 152 to and 1750 meter, the stress drop (Δσ) ranges between bar to and bar, the average radiant energy is ergs and the strain drop for the earthquake ranges from to respectively. The estimated stress drop values for NE India depicts scattered nature of the larger seismic moment value whereas, they show a more systematic nature for smaller seismic moment values. The estimated source parameters are in agreement with previous works. S3_C5 Analysis of The Seismic Activity of El Asnam Region F.Bellalem, M.Mobarki and A. Talbi (Seismological Dept.Survey. CRAAG. BP 63 Bouzareah Algiers-Algeria, The scope of this study is to analyze the seismic activity of El Asnam Region between 1980 and The regional seismicity analysis is based on reliable compilation of earthquake catalogs obtained from different agencies. All intensities and magnitudes were converted to Ms Magnitude using appropriate relationships. Dependent events were removed using adapted time and space windows. In addition, the completeness of the catalogue as a function of magnitude was determined from the standard deviation of occurrence rate plots, using the Stepp(1972) methodology. The remaining 320 independent earthquakes with Ms e 2.8 were used to obtain various parameters (b-value, z- value) to characterize the temporal and spatial seismic activity for El Asnam region. Finally, the obtained results are discussed to explain parameters variability. S3_C6 Stress Pattern in the Kangra-Chamba region of Northwest Himalaya from Focal Mechanism Solution. Dilip Kr Yadav Naresh Kumar and Chandan Bora. (Wadia Institute of Himalayan Geology, Dehradun , India) The Kangra-Chamba region of northwest Himalaya is seismically very active. The microseismicity recorded by a network of 36 stations for a period of about 5 years (January March 2009) shows that the activity is concentrated to the north of Main Boundary Thrust (MBT), in the Panjal Thrust (PT) and in the Chamba Nappe area. The maximum activity is confined down to 40 km depth. 47 fault plane solutions (FPS) of earthquakes, magnitudes 2.5<M<5.0, are used to for stress inversion. The FPS at shallower depth (<10 km) shows predominantly thrust to strike-slip with a NE-SW directed compression, and at deeper depth ( January, 2011

51 km) it shows normal faulting with small strike-slip component with a SW-NE directed extension. The low angle dipping inferred nodal plane of the shallower earthquakes is compatible with the under thrusting Indian plate. The FPS at the deeper depth, on the other hand, are interpreted with the local seismogenic faults. The stress tensor inversion results obtained from the FPS for the shallower events (depth <10 km) show that the maximum compressional stress (ó1) trends at 29º and plunges 6º degree, and the minimum stress axis (ó3) trends at 134º and plunges at 67º. Below 10 km the compressional stress (ó1) trends at 244º and plunges at 59º with tensional stress (ó3) trending at 9º with plunge of 20º. S3_C7 Estimation of Earthquake Source Parameters and Site Response fromgeneralized Inversion of Strong Motion Network Data in Kachchh Seismic Zone, Gujarat, India Prantik Mandal (National Geophysical Research Institute (CSIR), Hyderabad, India.); Utpal Dutta (University of Alaska Anchorage, Anchorage, AK, United States.) Inversion of horizontal components of S-wave spectral data in the frequency range Hz has been carried out to estimate simultaneously the source spectra of 38 aftershocks (Mw ) of the 2001 Bhuj earthquake (Mw 7.7) and site response at 18 strong motion sites in the Kachchh Seismic Zone, Gujarat, India. The spatial variation of site response (SR) in the region has been studied by averaging the SR values obtained from the inversion in two frequency bands; Hz and Hz, respectively. In Hz frequency band, the high SR values are observed in the southern part of the Kachchh Mainland Fault that had suffered extensively during the 2001 Bhuj Earthquake. However, for Hz band, the area of Jurassic and Quaternary Formations show predominantly high SR. It is apparent that in both and 3 7 Hz frequency bands, the presence of geological contacts and sediment thicknesses controls the site responses in the Kachchh seismic zone. It is also inferred that larger site response (>1:2) values in the Hz January, 2011 frequency band could be indicating the probable presence of soil class C (360 < Vs d 760 m=sec) and D (180 < Vs d 360 m=sec) in the Kachchh basin (according to 1997 National Earthquake Hazards Reduction Program [NEHRP] provisions). The source spectral data obtained from the inversion were used to estimate various source parameters namely, the seismic moment, stress drop, corner frequency and radius of source rupture by using an iterative least squares inversion approach based on the Marquardt-Levenberg algorithm. It has been observed that the seismic moment and radius of rupture from 38 aftershocks vary between 3.1x10 13 to 2.0x10 17 N-m and 226 to 889 m, respectively. The stress drop values from these aftershocks are found to vary from 0.11 to 7.44 MPa. A significant scatter of stress drop values has been noticed in case of larger aftershocks while for smaller magnitude events, it varies proportionally with the seismic moment. The regression analysis between seismic moment and radius of rupture indicates a break in linear scaling around N-m. The seismic moment of these aftershocks found to be proportional to the corner frequency, which is consistent for earthquakes with such short rupture length. S3_C8 Earthquake Interevent Time Clustering Inferred from Mixed Models Talbi A. ( M. Hamdache and M. Mobarki (Centre de Recherche en Astronomie Astrophysique et Géophysique CRAAG Département Etude et Surveillance Sismique.BP. 63 Bouzareah 16340, Algiers. Algeria) A simple mixed model is presented and fitted to earthquake interevent time distribution. The model uses power law and Weibull distributions at short and long interevent time ranges respectively. The corresponding proportions of dependent and background seismicity components are estimated based on the deviation between the empirical data distribution and our model. The proposed model is discussed and its parameters inferred to objectively separate the two seismicity components. 21

52 Subsequently, the seismicity catalog can be declustered without the subjective consideration of space time windowing. The procedure uses a correlation distance which is defined as a measure of clustering degree. Specifically, given a pair of events with interevent time τ, the probability that τ separate a correlated (clustered) pair is quantified using the deviation between τ and the mean interevent time τ. The simplest interpolation of the obtained percentage of clustered pair of events, suggest a V-shaped interpolation using two linear tendencies at short and long interevent times. The results show that a potential measure of the proportion of main events in the whole catalog background fraction can be obtained using the probability that interevent times deviate significantly from their mean. In this perspective, more interevent times deviate from their mean, more the corresponding events tend to be clustered. These findings are intended to help the construction of an objective stochastic declustering algorithm. Keywords. Interevent times, Mixed model, Declustering, Background seismicity S3_C19 Triggering is fine but what causes earthquakes in Koyna-Warna region? V.K. Gahalaut and Kalpna Gahalaut (National Geophysical Research Institute, Uppal Road, Hyderabad ) The Koyna-Warna region of relatively stable peninsular India is a unique site in the world where the seismicity that reportedly began soon after the impoundment of the Koyna reservoir in 1961 has continued for over 40 years. The main Koyna earthquake of December 10, 1967 (M 6.3) the largest earthquake near a reservoir, ever recorded globally, and the ongoing earthquake occurrences in the Koyna-Warna region have been considered as the reservoir triggered earthquakes. Our knowledge about the seismicity of the region prior to 1962 is very limited due to the absence of seismic stations in the area. Since 1963, more than 100,000 earthquakes, including about 200 of M>4, about 20 of M>5, have been reported from the Koyna- Warna region and frequency of the earthquakes of past 40 years is almost steady. All these earthquakes are considered to be triggered by the Koyna and Warna reservoir operations. Simulations of stresses and pore pressure due to the reservoir operation, visual inspection and statistical analyses of data support this view; however, what causes these earthquakes is still an enigma. The triggering mechanism requires that the faults should be critically stressed so that earthquakes with sense of motion commensurable with ambient stress direction may be triggered on those faults. This condition raises questions on the occurrence of earthquakes with normal motion in the Warna region in a predominantly compressive environment of the peninsular India. We propose that there are at least two predominant mechanisms operating in the region which may be responsible for such and all other earthquakes in the Koyna Warna region. We suggest that the sustained high seismicity in this region may be influenced by the geometry of the fault zones and their interactions through stress transfer. These distinct fault zones, inferred from the earthquake distribution and their focal mechanisms, are favourably oriented to each other in such a way that earthquake occurrences in one of the fault zones increase static stress on the other, facilitating frequent and continuing occurrence of earthquakes in the region. Stress triggering appears to be an important cause for continuing high seismicity as it brings some of the stabilized faults closer to failure in the manner consistent with the inferred sense of motion. Another important mechanism which seems to operate in the region is the effects of elastic plate flexure. The height of the Western Ghat escarpment is usually considered to be maintained by flexure in the east west direction. Intense erosion and sediment loading further control its evolution. We propose that this promotes failure at shallow depth by a reduction of the normal stress on escarpmentparallel sub-vertical planes in the region. We suggest that there could be some additional mechanisms controlled by the subsurface structures which may lead to continuous and renewable strain accumulation. Probably an accurate and dense subsurface imaging and crustal deformation monitoring may help in further exploring this aspect January, 2011

53 S3_C10 Source characteristics of Delhi earthquake (M L: 4.3 ) of 25 th Nov., 2007 Rajesh Prakash, A. K. Shukla and R. K. Singh (India Meteorological Department, New Delhi) The Delhi Sargodha Ridge (DSR) which traverse through NCT Delhi forms an important tectonic element in seismic hazard assessment of this region. The past study based on seismicity data generated by seismic telemetry network of Delhi region shows that the DSR is active and dominant mechanism in nucleation of seismicity is thrust with minor strike slip. Recently, a moderate magnitude earthquake (M L : 4.3) with epicenter at N / E occurred in Delhi (about 21Km south west of Delhi University) on 25 th Nov. 2007, was widely felt in Delhi and its adjoining areas. The fault plane solution using P-wave polarity data of Delhi seismic telemetry network shows a thrust with a minor strike slip component. The strike of one of the nodal plane dipping southerly conforms to the trend of DSR. The intensity map of this earthquake shows meisoseismal area elongated elliptically along NW-SE direction in the vicinity of DSR, which also implies that the source of this earthquake is due to the reactivation of tectonic activity along this. Another past earthquake (M L : 3.8) of date 28 April 2001, with epicenter in NCT Delhi exhibits fault plane solution in conformity to the trend of DSR S3_P1 Waveform inversion of local earthquakes using broadband data of Koyna - Warna region, western India D. Shashidhar N. Purnachandra Rao, D. Srinagesh, H.V.S. Satyanarayana and Harsh Gupta (National Geophysical Research Institute, Uppal Road, Hyderabad , India.) The Koyna-Warna region in western India is the best example of reservoir triggered seismicity. The world s largest triggered earthquake of magnitude 6.3 occurred on 10 December 1967 at Koyna, followed by several moderate to small earthquakes ever since. Recent seismicity studies based on deployment of a digital seismic network of 11 stations during August 2005 to December 2009 have indicated a concentration of seismicity towards south in the Warna region including a new zone of seismic activity to the south-west. Also, during the observation period, 18 earthquakes of magnitude 4 and larger have occurred out of which 16 occurred near the Warna region while only 2 occurred in Koyna. In the present study we model broadband waveform data of above earthquakes using waveform inversion approach. Several velocity models were tested to select the best one based on the criterion of maximum waveform match between observed and synthetic seismograms. In general, focal mechanisms of normal type with NS to NNW-SSE oriented fault planes are obtained for the Warna events which are correlated with probable faults indicated by LANDSAT images and aeromagnetic anomalies. Focal depths of the earthquakes in the Koyna-Warna region have been precisely determined based on the sensitivity of whole waveform inversion at local distances. The focal depths obtained near the Warna region are consistently in the range of 4-6 km, while two earthquakes near Koyna have focal depths of 8 and 9 km respectively. Joint modeling of hypocentral locations and velocity structure has provided a velocity model that produced lowest travel time residuals. S3_P2 Remotely Triggered Seismicity due to the 2001 Bhuj Earthquake G. Surve (Dr. K. S. Krishnan Geomagnetic Research Laboratory (I.I.G), Leelapur Road, Chamanganj, Allahabad , G. Mohan (Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai ) Evidence of remotely triggered seismicity at large distances due to strong earthquakes has been reported by several workers. We explore the evidence of one such episode of triggered seismicity in the Deccan volcanic province (DVP) of India, due to the Mw 7.7 Bhuj earthquake that occurred on 26 th January The seismic network January,

54 established by IIT Bombay, around Dalvat, 50 km northeast of Nasik, in south central DVP in Maharashtra, about 500 km south east of Bhuj, recorded an abrupt increase in the local seismicity following the devastating Bhuj earthquake. A swarm of about 55 microearthquakes, magnitude < 2.2, were recorded at Dalvat in a span of a few hours to three days immediately after the main Bhuj event. The network, which initially comprised of 4 short period stations at the time of occurrence of Bhuj earthquake was expanded to include a broadband (100s) station. The overall background seismicity for the area is quiet low as compared to the triggered seismicity, which contributed to nearly 70% of the total catalog of recorded events. Overall about 200 microearthquakes with magnitudes (Ml) ranging from 1.5 to 3.5 were recorded within the network during The triggered seismicity following a NW-SE trend and confined to shallow depth of < 2km within the basaltic cover, may have been triggered by the change in local stress field due to the Bhuj earthquake. The composite fault plane solution computed indicates strike-slip mechanism for the triggered events. These observations are significant as it is the first instance of triggered seismicity observed due to a large distant earthquake within the intrapale region. S3_P3 Evidence for Transverse Tectonics in Sikkim Himalaya from Seismicity and Source Parameter study Pinki Hazarika ( M. Ravi Kumar, G. Srijayanthi, P. Solomon Raju, N. Purnachandra Rao and D. Srinagesh, National Geophysical Research Institute Uppal Road, Hyderabad In the present study, over 700 local earthquakes in the region of the Sikkim Himalaya have been accurately located and analyzed using P and S travel times from a network of 11 broadband seismic stations operated by the National Geophysical Research Institute, Hyderabad. Further refinement of the hypocentral parameters using the hypodd relocation program resulted in well constrained hypocentral locations. 468 earthquakes having local magnitude (Ml) greater than or equal to 2 were used to determine source parameters like seismic moment (M 0 ), source radius (r), corner frequency (f c ) and stress drop (Äó). The estimated seismic moment ranges 1.9X10 12 Nm to 3.1X10 16 Nm with average value 2.1X10 13 ± Nm, corner frequencies 1.25 Hz to 7.06 Hz while the average is 2.62 ± 0.58, stress drop 0.56 bar to 131 bar with average 2.75 ± 10.4 bar and the source radius 0.2 to 1.12 Km with average value 0.55 ± 0.16 Km. Interestingly, this study reveals several characteristic features that distinguish Sikkim from the rest of the Himalaya. The seismicity distribution is found to be confined mostly between the main boundary thrust (MBT) and the main central thrust (MCT) but not quite associated with either. While the entire Himalayan front is generally characterized by shallow-angle thrust faulting, focal mechanisms in this region are predominantly of strike-slip type in conformity with a right-lateral strike-slip mechanism along the northwest-trending Tista and Gangtok lineaments. The P-axis trends of earthquake focal mechanisms are clearly oriented north-northwest, marking a clear transition from the ambient north-northeast trending direction of Indian plate motion with respect to the Eurasian plate all along the Himalayan front. Moderate-sized earthquakes occur down to 70 km depth in this region, compared to an average focal depth of km in the rest of the Himalaya. Also, a high average crustal P velocity of 6.66 km/sec and a fairly low b value of 0.83 ± 0.04 are obtained indicating the probability of occurrence of a higher magnitude earthquake in the future. Using least square approach found the relation between the logarithm of seismic moment (M 0 ) and local magnitude (Ml) as LogM 0 = 0.64Ml and relation between moment magnitude (M w ) and local magnitude (Ml) as LogM w = 0.73Ml which are little different from the standard relations. A north south section in the Sikkim region shows a relatively flat topography, unlike in the rest of the Himalayan mountain chain and suggestive of lower rates of convergence in the recent geologic past. It is proposed that crustal shortening in the Sikkim Himalaya has been substantially accommodated by transverse tectonics rather than underthrusting in recent times January, 2011

55 S3_P4 Right Lateral Strike Slip Environment in Kutch Rift, Northwestern India: Moment Tensor Inversion Studies. Ch. Nagabhushana Rao 1, N. Purnachandra Rao 2 and B.K. Rastogi 1 ( 1 Institute of Seismological Research, Raisan, Gandhinagar, Gujarat , India. 2 National Geophysical Research Institute (Council of Scientific and Industrial Research), Hyderabad, , India.) The Kutch region in northwestern India, close to the India-Arabia and the India-Eurasia plate boundaries, is a paleo-rift that has experienced devastating intraplate earthquakes in the past, namely the 1819 Allah Bund earthquake (M 7.8), the 1956 Anjar earthquake (M 6.0) and the 2001 Bhuj earthquake (M 7.7). Inversion of seismic waveform data of nine earthquakes in the magnitude range of 4 to 4.6 in this region recorded by the Institute of Seismological Research (ISR) during yields reverse faulting and strike slip faulting solutions in the depth range of 8.5 to 35 km. The inferred fault planes correlate well with the local trends of the tectonic faults, while the principal compressive stress direction derived from stress inversion trends agreeably with the ambient stress field direction of NNE-SSW. It is inferred that in the Kutch region a right lateral strike slip environment prevails along predominantly NW-SE oriented deep-seated preexisting faults in an otherwise reverse fault regime governed by the Indian plate collision with respect to the Eurasian landmass January,

56 S4_Keynote-1 Luminescence Dating in Paleoseismology and Neotectonics: An Overview The 2001 Bhuj Earthquake and Advances in Earthquake Science (AES-2011) S4: Paleoseismology and Historical Seismology Conveners : Susan Hough, Roger Bilham and Javed N. Malik A.K. Singhvi 1 ( R.N. Singh 2 ( and M.K. Murari 1* ( 1 Physical Research Laboratory, Ahmedabad , India. 2 INSA Senior Scientist, NGRI, Hyderabad , 1* Present Address: Department of Geology, University of Cincinnati, Cincinnati OH USA) Luminescence dating relies on the use of natural minerals as dosimeters of natural radiation field arising due to the decay of U, Th and K in the rocks/ sediments, along with the cosmic rays. The method enables the dating of the most recent heating (to 400 C) or the most recent exposure a few seconds, to clear day light. This fact makes it possible to date a variety of seismic/tectonic events. These include, 1) the dating of fault-gouge (heating during faulting), 2) the dating of fault scarp (daylight exposure during scarp formation), dating of sand dykes (thermal resetting during dyke formation), 3) dating of seismeites (day light exposure of the sediment at the sediment -water interface) and, 4) via the dating of sediments above and below the deformed strata. These open new possibilities in quantitative paleoseismology. THEME Historical earthquake studies, which typically involve development of modern methods to analyse macroseismic data from archival sources, can provide invaluable information about earthquake processes and earthquake hazard in Asia, which boasts both wealthy ancient cultures and significant earthquake hazard. However, the historical catalogue of earthquakes is still substantially incomplete in several countries which are under the threat of earthquake hazard. Paleoseismological studies, including traditional trenching as well as other methods, provide a complimentary approach to identify and investigate the historical and pre-historical earthquakes signature preserved in the geological record. Such investigations have also been carried out in some countries, although many targets remain to be explored to better quantify fault slip and earthquake rates. We invite papers that present the results of historical and paleoseismological investigations of earthquakes and faults in Asia, including contributions that explore the implications of results for basic questions involving fault and earthquake processes, and seismotectonics. We also invite contributions that explore the implications of results for improvements in hazard assessment. Modeling efforts indicate that the even minor slips can generate sufficient heat to thermally reset the geological luminescence of the rocks in the fault zones, (Murari et al, 2009). In sand dykes, the observed resetting of the luminescence has been enigmatic but the modeling efforts indicate thermal resetting, during dyke injection at high velocities with associated grain friction (Singh et al., 2009). In this presentation, we shall outline som e of the basic elements of luminescence dating in the context of dating past seismic events and present some case studies to elucidate the methodological aspects of the method in dating such events. Flash heating of faults and resetting of TL clock in shallow earthquakes, M.K. Murari, R.N. Singh and A.K. Singhvi. Abstract O31, Second Asia Pacific Seminar on Luminescence and ESR dating, Nov , 2009, Physical Research Laboratory, Ahmedabad, , India, p. 81. Flash Heating in Sand Dykes: A possible zeroing mechanism for OSL dating, R.N. Singh, M.K. Murari and A.K.Singhvi. Abstract O30, Second Asia Pacific Seminar on Luminescence and ESR dating, Nov , 2009, Physical Research Laboratory, Ahmedabad, , India, p January, 2011

57 S4_I1 Active Faults in Kachchh Region and Issue on the Seismic Hazard Assessment M. Morino ( J. N. Malik ( and F. Kaneko ( The 2001 Bhuj earthquake (Mw 7.6) was firstly estimated to be generated by the Kachchh Mainland Fault (KMF), due to the serious damages at Bachau and Bhuj Towns. However, the aftershock distribution revealed it has been generated by a blind fault located on the north of the KMF. Our trench investigation across the KMF and the Katrol Hill Fault (KHF), carried out as part of the Seismic Microzonation of Gandhidham project, confirmed they are active for the first time. The results showed that the KMF is a reverse fault inclined to the south and the amount of the netslip for a single seismic event is around 5m. The KMF displaced all layers except top soil, inferring it might rupture during historic age. For the KHF, there is a branched fault which may cross beneath the Bhuj Town. There are no historic documents on the paleo-earthquakes along the KMF and KHF. This may suggest the possibility of their rupture in near future with a long elapsed time since the last earthquake. If the KMF and/or the KHF rupture in near future, Bachau, Bhuj, and Gandhidham must suffer severer damages than the 2001 earthquake. S4_C1 Partitioning of convergence in Northwest Sub Himalaya: indication from convergence and slip rates estimated across Kangra Reentrant, North India V.C. Thakur ( D.Sahoo, Ajit Singh, N. Suresh, M. Joshi and R. Jayangondapermal (Wadia Institute of Himalayan Geology, Dehradun , India) During Holocene, 21 mm/yr and 13 mm/yr northsouth shortening on the Himalayan Frontal Thrust was reported in the Central Nepal and the Garhwal Sub Himalayas respectively. These rates were interpreted as representing the shortening accommodated on the Main Himalayan Thrust (MHT) decollement. In the Kangra reentrant of Himachal Pradesh in northwest Sub Himalaya, the long term shortening rate of 14 ± 1 mm/yr between the Main Boundary Thrust and the Himalayan Frontal Thrust has been estimated earlier based on balanced cross-section. On the short term, the GPS measurements have indicated 14 ± 2 mm/yr interseismic slip on the MHT. Using uplifted strath terraces and fan surfaces on the hanging walls of thrust faults, the uplift, convergence and slip rates due to faulting are computed. Shortening rates calculated on the Jawalamukhi Thrust (JT) is 3.49 mm/yr during 32 ka and 4.86 mm/yr during 17 ka. The Soan Thrust (ST) yields shortening and slip rates of 2.98 mm/yr and 3.44 mm/yr respectively during 29 ka. The shortening and slip rates on the HFT are estimated as mm/yr and mm/yr respectively during 42 ka. These rates represent convergence accommodated along the Main Himalayan Thrust (MHT) by fault segments HFT- MHT, ST-MHT and JT-MHT during different periods of time. This may have implication for seismic hazard assessment in the Kangra reentrant which was affected by the 1905 Kangra earthquake Mw> January,

58 Balanced cross-section across Kangra reentrant showing shortening/ slip rates on thrust faults computed in our study. Long and short terms total shortening/slip rates between the HFT and MBT (After Powers et al, 1998, Banerjee, P., Burgmann, R., 2002). S4_C2 Paleoseismic investigations in the Kopili Lineament Zone, Northeast India. Devender Kumar ( D.V. Reddy and P.Nagabhushanam (National Geophysical Research Institute (Council of Scientific and Industrial Research), Uppal Road, Hyderabad (India)) Paleoseismological investigations are used to constrain the historic/pre-historic earthquakes specially that occurred during pre-instrumental period. NE India is one of the active seismic zones frequented by large to great earthquakes in the recent and distant past. Being located between the meizoseismal areas of the 1897 Great Assam earthquake and the 1950 Upper Assam Earthquake, the Kopili Lineament Zone (KLZ) has high potential for large to great earthquake in future even though the stress is being released through several tremors of the order of M 4.5, apart from the major earthquakes of 23 rd October 1943 (M 7.2) and the Cachar earthquake of 1869 (M 7.5). The recently increased seismicity along the Kopili lineament warrants the importance of looking into the past seismic history of the area. The present paleo-seismic studies in this region mainly concentrate on locating, documenting and constraining the timing of seismogenic liquefaction features. The 14 C and optically stimulated luminescence (OSL) chronology of the organic material and sediments associated with these features provide a seismic history of approximately last 1000 years. During this period, the region is inferred to have experienced at least three major seismic events occurring at (i) 1000 yr BP, (ii) between yr BP, and the latest one (iii) between yr BP. Missing are the age components which could constrain the October 23, 1943 earthquake, and feeble evidence obtained for the 1869 Cachar earthquake. S4_C3 Paleoseismology along an intraplate fault: Talas-Fergana, Tien-Shan mountains, central Asia Derek Rust (School of Earth and Environmental Sciences, University of Portsmouth, UK, Andrey Korjenkov, Alexander Bobrovskii and Ernes Mamyrov (Institute of Communication and Information Technologies, Kyrgyz-Russian Slavic University, Bishkek, Kyrgyzstan), The Talas Fergana fault bisects the Tien Shan Mountains, the northernmost expression of Himalayan deformation, and displays classic features of recent activity. Historical and instrumental records indicate that no ground rupturing earthquakes have taken place in the last 250 years, despite many large earthquakes occurring elsewhere in this actively deforming region, suggesting the Talas-Fergana may represent a seismic gap. Our field study has concentrated on three reaches of the fault zone that display multiple indicators of recent offset. In the first, radiocarbon dating of organic-rich fill collected from one in a series of en echelon faulting-generated fissures gives an age of 480+/-35 BP, while a dissected peat blanket on the upthrown side of a scarp interpreted to have been produced by the last faulting event yields dates of 405+/ -100 BP and 460+/-40 BP. Farther southeast the second and third sites display perched channels recently abandoned by drainage, now entrenched in more direct courses, which were previously deflected along the fault. The entrenched channels have both been offset by similar amounts (55-60 and ~70 m) of post-entrenchment fault movement. Exploratory pits dug in the perched channels provided samples for OSL and 14C dating and, although further dating results are awaited, suggest the entrenchment event took place 5-6 Ka ago, indicating a slip rate since of mm a -1. Dates from the upper part of one perched channel fill, and from a small terrace deposit upstream on the related entrenched drainage, are respectively 505+/-80 BP and 440+/-45 BP. The statistically indistinguishable recent 14 C dates, which coincide with archaeoseismic dating from a ruined Silk Road caravansary in the region, and with published lichonometry results from a nearby large and probably seismically-triggered landslide deposit, suggest that faulting last occurred between 400 and 500 BP, and indicate a major event rupturing >100 km of the fault January, 2011

59 The authors acknowledge the support of NATO Science for Peace, Project S4_C4 Active fault mapping using high resolution geophysical field investigation in Kachchh: Implication to Quaternary rejuvenation A.K.Gupta Girish Ch. Kothyari, Rashmi Pradhan, Mukesh Chauhan,R. K. Dumka, R. K. Singh and B.K. Rastogi(Institute of Seismological Research, Gandhinagar , Gujarat, India) The landscape of Kachchh has been shaped by multiple step tectonic movements along various faults. These faults originated due to the break-up and northward drift of the Indian plate. In the northern margin of Kachchh region significant features related to active deformation have been observed. On the basis of field observations, it seems that the area is under influence by NE-SW trending oblique slip tectonic movement with reverse component over the E-W major faults. Ground deformation has been observed in the fault zones as uplift and subsidence of ground. The E-W compressive force in the region has resulted in the development of folding of Quaternary sediments in Great Rann of Kachchh (GRK). Some micro-earthquake activities have also been noticed along the NE-SW tectonic trend. High resolution geophysical GPR survey with a 200 MHz receiver has been conducted in the area to verify the active deformation. A total of 1 km long N-S GPR records were collected across the IBF zone. 2D GPR Image clearly indicates development of major fracture at a depth of 6m, which may be formed due to compressional tectonic environment. These observed faulted features were validated and cross checked by conducting gravity survey using CG-5 auto gravitymeter at 1 km station interval (approx.) for better understanding of deformation within NE-SW tectonic trend. The topographic feature in the region, showing sudden changes in relief, is reflected by low bouguer gravity. Steep gradient in Bouguer and free air gravity anomalies between Amarapar and Lodrani reflects faulted basement in the area. Towards the Balasar sudden drop in gravity seen in gravity profile and also reflected in the topography in the form of sudden changes in gradient, this could be due to differential uplift in IBF and NE-SW trending fault. Similar situation has been observed in Chitrod - Balasar section of Wagad region. The topographical expression in Chitrod region shows high relief whereas towards Balasar the gradient is decreasing. Negative gravity response in high relief areas might be due to rejuvenation and upliftment of sedimentary structures. S4_P1 Morphotectonic control on drainage network evolution in the Upper Narmada Valley: Implication to Neotectonic Girish Ch. Kothyari ( and B. K. Rastogi (Institute of Seismological Research, Raisan, Gandhinagar, , Gujarat India); The intra-continental convergence of the Indian plate towards Eurasia is being reflected in the recurrent fault movement in the form of neotectonics. Neotectonic features have been observed using geomorphometric analysis of small catchments area of upper Narmada basin using high resolution ASTER and SRTM-DEM data. Parameters like topographic cross-sections, longitudinal river profiles, stream length gradient index (SL) and asymmetric factor were studied to understand tectonic movement. The stream length gradient index (SL) suggests differential uplift along the Narmada valley. Sudden changes in slope of Narmada river floor is seen as knick points along South Narmada Fault (SNF) and along Jabalpur Fault. Drainage basin asymmetry of upper Narmada basin has been used as a quantitative parameter to understand tectonic deformation. The cross topographic profile has been generated using DEM data to understand the landscape evolution pattern of upper Narmada basin. Various tectonically induced geomorphic signatures have been identified using satellite Google Image in the region such as fluvial incision in bedrocks, formation of gorges with vertical walls and shifting of river channel towards NNW direction. All the above features indicate neotectonic activity January,

60 S5: Earthquake Precursors and Prediction Studies Conveners : B.R. Arora and R. K. Chadha THEME Recognizing that earthquake precursory research hold key to earthquake prediction, search for precursors and their documentation has continued in different parts of the globe. Accumulated evidences bring forth variety of precursory signals including seismological, atmospheric/ionospheric, geodetic/geomagnetic, electrical resistivity/ hydrological as well as geochemical anomalies. Despite certain definite success cases, skepticism prevails as noted changes are not observed at all earthquakes sites or even for different earthquakes in the same region. The dilatancy-diffusion model based on behavior of rocks under stresses in laboratory conditions has some success in explaining some of the noted precursory signals. Induction of con-current multi-sensor measurements and availability of satellite data have begun to demonstrate the promising role of nonseismological parameters in earthquake forecasting programs. The present session shall review the advances in earthquake precursory programs to devise road map for future planning and practical application of earthquake precursory research. Papers dealing with any aspect of earthquake precursory research are welcome. Papers focusing on modern mathematical tools to isolate precursory signature in real time, establishing their space-time relation to earthquake cycle and highlighting strategies for integrating multisensor data are especially invited. S5_I1 Changing Scenario of Earthquake precursory Research B. R. Arora (Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun , India. Fax ) The space-time pattern in micro-seismicity, seismic swarms, seismic wave velocity change, b value, RTL algorithm in a given seismic zone show promise in identifying precursors to impending earthquakes. Despite some success stories, pessimism prevailed as noted changes were not observed at all earthquake sites or even for different earthquakes in the same region. The lack of sound physical hypothesis that could explain and validate precursory behaviors further added to the skepticism. The dilatancy-diffusion model based on behavior of rocks under stresses in laboratory conditions has some success not only in explaining the noted seismological precursors but also suggested presence of small-scale changes in gravity, resistivity, magnetic field intensity, electromagnetic and radon gas emission as well as fluctuations in hydrological parameters. Given that the numbers of parameters are expected to show characteristic space-time variation during the earthquake preparatory cycles, task force constituted by Ministry of Earth Sciences, Govt of India has recommended simultaneous measurements of interdisciplinary parameters. Given this realization, Wadia Institute of Himalayan Geology (WIHG) has established the first Indian Multi-Parameter Geophysical Observatory (MPGO) at Ghuttu, Central Himalaya to study earthquake precursors in integrated manner. Located in a narrow belt of high seismicity, just south of the Main Central Thrust of the Himalaya, has been the seat of recent Uttarkashi and 1999-Chamoli earthquakes, both M> 6. The MPGO became fully operational in April 2007 and is equipped with super conducting gravimeter, overhauser magnetometer, tri-axial fluxgate magnetometer, ULF band search coil magnetometer, radon data logger, water level recorders and is backed up by the dense network of Broad Band Seismometers (BBS) and GPS. The critical analysis of various geophysical time series indicates that the time-variability of gravity field is influenced by soil moisture and water table fluctuations, geomagnetic field changes are sensitive to solar-terrestrial dynamics, flux of radon emission is strongly dependent on environmental factors like temperature and hydrology. These influences are the major deterrent in the isolation of weak precursory signals. The presentation shall focus on the data adoptive January, 2011

61 techniques to estimate and eliminate effects of solarterrestrial, hydrological/environmental factors on different geophysical time series. Some examples will be presented to demonstrate if effects of environmental and hydrology are not recognized and corrected, some anomalies will be falsely viewed as earthquake precursors. On the other extreme, some precursory signals are masked by factors other than stress-induced changes. Choice of session: Earthquake precursor and Prediction of Earthquakes Status of paper: Invited Key note talk Fax: S5_I2 Monitoring Well water level changes What did we learn from our experiences in India? R K Chadha (National Geophysical Research Institute, Hyderabad The human quest for predicting earthquakes in the last few decades has led to several claims of successful predictions ranging from geophysical to geochemical precursors to abnormal animal behavior. Except for a few cases, most of these claims have been post earthquake occurrence. While some of the studies are based on well documented measurements several of them are isolated measurements based on single instrument leading to high uncertainties related to earthquake prediction research. Well water level changes associated with earthquakes is one of the precursors recognized by the IASPEI sub-commission on earthquake prediction. In the Koyna region in Maharashtra, well water levels are being monitored since 1995 in 21 bore wells drilled around the seismically active region. Fourteen of the observation wells act as volume strain meters as their water levels show earth tidal signals. The analysis of more than a decade data show three types of response of the well water levels to seismotectonic effects, i) one to local earthquakes, ii) to regional and teleseismic events, and iii) to local fluctuations in rock strain on regional scale. Five cases of co-seismic step-like well water level changes, of the order of few centimeters in amplitude, related to earthquakes in the magnitude range January, d Md 5.2 are observed. All these earthquakes occurred within the network of wells drilled for the study and within 25 km distance of the recording wells. In three cases, drop in well levels preceded co-seismic step-like increases, which may be of premonitory nature. The second type of response is observed to be due to the passing of seismic waves from regional and teleseismic earthquakes like the M 7.7 Bhuj event on January 26, 2001 and the M 9.3 December 26, 2004 Sumatra earthquake. The third type is a well level anomaly of centimeter amplitude coherently occurring in several wells. The anomalies are similar in shape and last for several hours to days. From our studies we conclude that the wells in the network appear to respond to regional strain variations and transient changes due to distant earthquakes. The two factors which are important to co-seismic steps due to local earthquakes are the magnitude and epicentral distance. From the limited number of events we found that all local earthquakes exceeding Me 4.3 have produced co-seismic changes. No such changes were observed for earthquakes below this magnitude threshold. No simple model exists to connect pre- or co-seismic fluctuation of ground water levels. The sensitivity of deep wells to seismic activity is remarkably varied. In China, several successful earthquake related anomalies have been reported for earthquakes occurring halfway round the world. This may be due to the fact that these wells are very deep. Over 100 research wells in excess of 1000 m deep have been drilled solely for earthquake prediction purposes in China. Similarly, in Japan and other countries well water levels are being monitoring in very deep bore wells. In my presentation, results from Indian experiment in Koyna and other worldwide cases will be discussed. S5_C1 Soil-gas Geochemistry for Earthquake Monitoring and Fault Studies in Taiwan Vivek Walia 1*, T.F.Yang2 C-C. Fu 2, S-J. Lin 1, K. L. Wen 1 and C-H Chen 1 ( 1 National Center for Research on Earthquake Engineering, NARL, Taipei-106, Taiwan, * 2 Department of Geosciences, National Taiwan University, Taipei- 106, Taiwan ) 31

62 The study of active faults and earthquake precursory signals provides a basis for anticipating the future earthquakes and related phenomena such as surface failure, faulting, and other geological/tectonic features. The Island of Taiwan is a product of the collision between Philippine Sea plate and Eurasian plate which makes it a region of high seismicity. In the southern part of the island the Eurasian plate is subducting under the Philippine Sea plate while in the northern area of the island the Philippine Sea plate bounded by the Ryukyu trench is subducting beneath the Eurasian plate. Behind the Ryukyu trench, the spreading Okinawa trough has developed. The northern part of Taiwan Island is located at the western extrapolation of the Okinawa trough. The present study is proposed to investigate geochemical variations of soil-gas composition in the vicinity of the geological fault zones and to determine the influence of such formations on the enhanced concentrations of different gases in soil to monitor the tectonic activity in the region. To carry out the present investigations, variations in temporal soilgases compositions were measured at continuous earthquake monitoring stations established along different faults. Before selecting a monitoring site, the occurrence of deeper gas emanation was investigated by the soil-gas surveys and followed by continuous monitoring of some selected sites with respect to tectonic activity to check the sensitivity of the sites. From the results of long term geochemical monitoring at the established monitoring stations we can divide the studied area in two different tectonic zones. We proposed tectonic based model for earthquake forecasting in Taiwan and tested it for some big earthquakes occurred in recent past. Based on the anomalous signatures from particular monitoring stations we are in a state to identify the area for impending earthquakes of magnitude e 5 and we have tested it for some earthquakes which rocked the country in last six months. Most of the earthquakes having magnitude e 5 with local intensity e 2 at the monitoring stations, epicentral distance < 100 kms with focal depth < 40 kms have shown precursory signals and fitted very well according to the proposed model. S5_C2 Fractal Correlation Dimension Analysis to identify precursory pattern prior to 15th July 2009 New Zealand earthquake (Mw-7.8). S.K. Mondal, R. Meena and and P. N. S. Roy of Applied Geophysics, Indian School of Mines, Dhanbad , Jharkhand, INDIA; Phone : ; FAX: ) New Zealand is located along a zone of contact between pacific and Australia plates. The motion of these plates leads to the major seismicity in this country. The area of study with latitude 42 S to 50 S and longitude 162 E to 178 E experience frequent intermediate earthquakes and also some strong earthquakes. Seismically-active fault zones are complex natural systems exhibiting scaleinvariant or fractal deformation leading to earthquakes fractally distributed in space. Temporal variations of spatial fractal (correlation) dimension Dc have been related to the preparation process for natural earthquakes and rock fracture in the laboratory experiment by the scientific community. We investigate the temporal variation of spatial Dc for seismicity in the study area for earthquakes of magnitude > 3.9 occurring in the period between 1973 to2009. The analysis of fractal correlation dimension of earthquakes provides some low Dc value before the mainshock. The three consecutive windows of hundred events were observed to have low value having mean time 3/3/2007, 12/9/2007 and 22/2/2008.The mainshock was observed to have occurred after three low Dc windows. The low Dc (0.664) has been observed prior to main shock. These statistical scaling properties of seismicity may therefore have the potential at least to be sensitive for intermediate-term warning of major earthquakes. As the low Dc is an indicator of clustering and it shows how intermediate size events correlate with each other. Hence low Dc value may be high stress indicator along the fault of the study region which is responsible for strong earthquake, and one can say about the impending large earthquake. Thus this study may be applied for well constrained catalogue of a region for assessing the hazard of that region spatio-temporarily and which may be very useful information for hazard mitigation January, 2011

63 Key Words: Fractal Correlation Dimension, Seismicity and Clustering. S5_C3 Investigations of anomalous signals prior to large earthquakes based on 1-Hz superconducting gravimeter records and broadband seismometers data WenBin Shen 1,2, Dijin Wang 1, Cheinway Hwang 3, Jun Yi 1 ( 1 Department of Geophysics, School of Geodesy and Geomatics, Wuhan University, China. 2 Key Laboratory of Geospace Environment and geodesy, Wuhan University, China, 3 Department of Civil Engineering, National Chiao Tung University, Taiwan) We investigate the anomalous signals prior to about 30 large earthquakes (with seismic moments larger than7.0) occurred in the period ranging from 1 Jan and 31 June 2010 using 1-Hz data recorded by a superconducting gravimeter (SG) at Hsinchu station, Taiwan and by more than 10 broadband seismometers (BSs) distributed over the globe. We compute the power density spectra (PDS) of the records both in the non-seismic period and seismic period (the period just one or several days prior to large earthquakes), and compare the non-seismic PDS with the seismic PDS to see whether there are anomalous signals prior to large earthquakes. In another aspect, we apply Hilbert-Huang transformation (HHT) technique to the SG and BSs records to establish the time-frequency-energy paradigms to examine whether there are anomalous signals prior to large earthquakes. Both the results of the PDS comparisons and the examinations of HHT timefrequency-energy paradigms suggest that before more than 50% large earthquakes there appear anomalous signals. Our investigations also suggest that the anomalous signals prior to large earthquakes may be related to the magnitude, focal depth, fault orientation and distance between the observation station and the epicenter. Further investigations in more details are still in progress. This study is supported by Natural Science Foundation China (Grant No ; ) January, 2011 S5_C4 Changes Observed Prior and After the Gujarat Earthquake of 26 January, 2001Using Multi Sensor Satellite Data Ramesh P. Singh 1, 2 and Waseem Mehdi 2 ( 1 School of Earth and Environmental Sciences, Schmid College of Science, Chapman University, One University Drive, Orange, CA 92866, USA, 2 Research and Technology Development Centre, Sharda University, Greater Noida , India) Soon after the Gujarat earthquake (Ms 7.6) of 26 January, 2001, detailed analysis of multi sensor satellite data (IRS P4 OCM, MSMR, MODIS, SSM/ I, TOMS, MOPITT) together with meteorological data have been carried out. Pronounced changes in surface, ocean, atmosphere and meteorological parameters have been observed prior and after the earthquake. The changes observed in surface, ocean, atmosphere, meteorological parameters show complementary behavior. Such complementary nature is also observed in total electron content. The total ozone column observed from TOMS data show pronounced increase after the earthquake. All these changes show an evidence of the existence of a string coupling between Lithosphere-Atmosphere- Ionosphere and associated with Gujarat earthquake. A simple model will be presented that show that the observed changes could be related to the earthquake processes depending upon the subsurface configuration of the epicentral region. S5_C5 Application of acoustic sounding in earthquake precursor detection: lessons from Bhuj, India earthquake H.N. Dutta ( and B.S. Gera (Roorkee Engineering & Management Technology Institute, Shamli ) The death and destruction caused by the Bhuj, India earthquake led to many scientific postmortems of the coincidentally available geophysical data. One such observation was that of an acoustic sounder operating at Vapi (Gujrat) in which an anomalous atmospheric gravity wave was recorded propagating in the lowest part of the atmosphere on January 25, 2001, a day prior to the occurrence of earthquake 33

64 on January 26, This wave was the first signature of a wave with an amplitude of about 480m and a wave period of 4 hours ever recorded in India /Antarctica in the past 30 years. The investigators have been operating acoustic sounders as part of the planetary boundary layer program to monitor the atmospheric thermal structure right from surface up to a height of 1km on continuous basis. On the basis of this single observation, the investigators have been able to take an international patent and have established that acoustic sounders should be part of all earthquake precursor investigations, where, the coupling mechanism between geosphere-atmosphereionosphere coupling has to be understood. It may be pointed out that acoustic sounding offers a unique photographic display of all atmospheric processes in the atmosphere, therefore, the impact of any escape or leakage of energy, mass or momentum would be ideally mapped / photographed in real terms, the only part that has to be emphasized at the moment is that couple of acoustic sounders must be deployed at suitable sites in India or collocated with other earthquake precursor monitoring techniques so that a firm conclusion is drawn and a branch of science, where India has taken a lead, the lead remains maintained. The details shall be presented about the capability of the technology and its real time application in earthquake precursor technology. S5_C6 Anomalous Changes in Groundwater and Soilgas Radon concentrations in Relation to Earthquake Activities in Garhwal Himalaya, India: understanding this phenomenon as an earthquake precursor R.C. Ramola(Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal , India.), Sushil Kumar(Wadia Institute of Himalaya Geology, 33 GMS Road, P.B.No.74, Dehra Dun (UA), India, Phone: , ) During the last three decades, research on earthquake related radon monitoring has received enormous attention. It has found to have a great potential as a reliable precursor for an impending earthquake. This paper presents some results of continuous monitoring of radon levels in soil-gas and spring water at Tehri (Garhwal Himalaya), India. Efforts have made to correlate the variation of radon concentration in spring water with seismic events in the study area. Sudden increases in radon concentration in soil-gas and spring water were observed before, during and after the earthquakes occurred in the area. The variations in radon concentrations in soil-gas and spring water have found to be correlated with the seismic activities in the Garhwal Himalaya. The significant correlation between radon anomalies and earthquake activities in Garhwal Himalaya shows that this noble technique may be exploited as an additional tool in earthquake prediction program in Himalayan region. To be useful as a precursor in an earthquake prediction program, the continuous measurements of radon along with other precursors at several sites in a grid pattern is necessary. The role and usefulness of radon in soilgas and spring water as an earthquake precursor are discussed in this paper. S5_C7 Anomalous variations of fof 2 during Bhuj earthquake of 26 January2001 and association of GPS based total electron content with different seismic events O.P. Singh and Vishal Chauhan (Department of Physics, Faculty of Engineering & Technology, R.B.S. College,Bichpuri, Agra , India); Birbal Singh(Department of Electronics & Communication Engineering, Faculty of Engineering & Technology, R.B.S. College, Bichpuri, Agra , India.) The Bhuj earthquake of 26 January, 2001 (M=7.6) was the most severe earthquake in respect of wide spread damage to life and property ever seen in India during the last 50 years. The effect of this earthquake is examined on the nighttime ( h LT) ionospheric parameter fof 2 by employing the digital ionosonde data obtained from Ahmedabad (Geographic latitude, N, longitude, E). The percent deviation of fof 2 from monthly median for pre-midnight ( h LT) and post-midnight January, 2011

65 ( h LT) sectors are examined critically. The results show that fof 2 are reduced in both the time sectors prior to the occurrence of main shock. The effects of magnetic storms in reducing the fof 2 are identified clearly and they do not vitiate the effects of earthquakes. To investigate the effect of earthquakes on the ionosphere we have also carried out the GPS based total electron content (TEC) observations at our Agra station (Geographic latitude, 27 0 N, longitude, 78 0 E). For this purpose a dual frequency GPS receiver has been in continuous operations since 24 June, Since then the morphological features of TEC data have been studied and the TEC variations during the various seismic events also have been examined. It has been found in different cases that during the quiet geomagnetic conditions TEC data show perturbed behavior prior and after the occurrence of earthquakes. S5_C8 Signature of Seismo-Electromagnetic Signals (SES) in prediction of earthquakes Vinod Kumar Kushwah ( M.S.Gaur ( R.K.Tiwari ( and Rudraksh Tiwari ( Worldwide, medium to short-term earthquake prediction is becoming ever more essential for safe guarding man due to an un-abating population increase, but hitherto, there have no verifiable method of reliable earthquake prediction developed-except for a few examples of such in China and in Greece. The occurrence of earthquake is a global phenomenon. Earthquakes occur due to movements along the faults that have evolved through geological and tectonic processes. These are most disastrous of all the natural calamities as they affect large areas causing death, injuries and destruction of physical resources on a massive scale. No any country in this time which escape the disaster of earthquake. We have analysed the data of HF to ULF (Ultra Low Frequency) are found very interesting results to confirm the precursory nature of seismoelectromagnetic emission which are generated before during and after the seismic activities. Now, we are trying to develop a new technique of detection the seismic singles by live sensors (i.e. Tree Biopotential). This technique will play a very crucial role in the field of prediction techniques. Firstly of all, we analysed the data of tree bio-potential (off line) and try to correlate the drastically change of concentration of internal contents (Xylem and phloem) due to generate of electromagnetic emissions which produce the precursory nature of seismic activities. Keywords: Earthquake, ULF (Ultra Low frequency), Bio-potential, etc., S5_C9 Precursory Earthquake Studies in Maharashtra, especially in Koyna Region Arun Bapat¹ and M.A.Ghatpande² ( 1 1/11, Tara Residency, 20/2, Kothrud, Pune , 2 Formerly from MERI, Nashik, 1. Introduction: During last 400 years, there are three earthquakes of magnitude more than six in the State of Maharashtra (1). The last two earthquakes, i.e. Koyna earthquake of Magnitude 6.5 on 11 th December 1967 and Killari (Latur) earthquake of Magnitude 6.3 on 30 th September 1993 were devastating and have occurred within a span of 26 years. The belief that Deccan Trap region of Maharashtra is seismically stable was shattered by the Koyna earthquake and confirmed by the Killari earthquake. After observing the seismic activity in the Koyna region in , the monitoring of seismic activity in the State was initiated. At present there are about 53 seismological observatories in the state of monitoring seismicity. Various National Organizations like India Meteorological Department (IMD) New Delhi, National Geophysical Research Institute (NGRI) Hyderabad, Geological Survey of India (GSI) Nagpur, Indian Institute of Technology (IITB) Powai and Maharashtra Engineering Research Institute (MERI) Nashik are engaged in this activity. The numbers of seismological observatories by these organizations are as follows: January,

66 1) IMD : 7 2) NGRI : 7 to10 3) MERI : 35 4) IITB : 3 5) GSI : 1 Total : 53 MERI acts as a Nodal Agency appointed by Government of Maharashtra for earthquake studies in the State. The seismic data from the observatories of different Institutes are analyzed and interpreted separately. There is a need to combine all the available data for better evaluation and co-ordination of observed results. 2. Seismicity of Maharashtra: The Historical seismicity of Maharashtra reveals that the coastal Maharashtra has been seismically active since historical period. Based on seismicity, Maharashtra can be divided into six regions. These are: Koyna-Warna Region (Dist.Satara): Seismically this is the most active region in the State. Highest magnitude recorded is 6.5 in Dec Killari Region (Dist.Osmanabad & Latur): The area has also seismic potential, but apparently the seismicity has died down considerably after the devastating earthquake of magnitude 6.3 in Sep Bhatsa Region (Dist.Thane): The above area was seismically active in At present, seismicity has almost petered off. The highest recorded magnitude happens to be 4.9 in Sep Surya Region (Dist.Thane): The Surya area was seismically active in At present the seismicity has been almost died down. The highest recorded magnitude in this region is 3.8. It was in Aug Kalvan-Peth Region (Dist.Nashik): The spurt of micro-seismic activity has been recorded near Dalvat area of Kalvan tashil and Kohar-Bhaigaon area of Peth Tahsil.The maximum recorded magnitude earthquake has been 3.3 in Rest of Area : Spurt of Microseismic activity and individual earthquake events have been recorded at Ramtek (Nagpur), Nandurbar, Bhandara, Nanded, Bote(Ahmednagar), Dapoli (Ratnagiri),Yeotmal, Wasim, Sironcha (Chandrapur), Palghar (Thane), Akole and Pune. 3. Precursory Earthquake Studies: A Global Scenario Earthquake prediction has always been the subject of challenge to the earthquake scientists the worldover. It is an old and elusive goal of seismologists. In India, Ballala Sena (10 th -11 th century A.D.) in his Adbhuta Sagara has written about causes of earthquake. Varah Mihir (5 th 6 th century A.D.) (2, 3) has tried to establish atmospheric phenomena as a possible precursor for earthquake prediction. He proposed that the four elements viz. Wind, Fire, Water, and Indra cause the earth to shake. Harry Reid, a geologist in 1910 proposed that it may be possible to predict the Time and Place of earthquakes by monitoring stress along faults. In seismically vulnerable areas like Japan, China, Russia, Mexico and USA comprehensive research programmes have been carried out, so that earthquakes could be predicted in terms of Location, Time and Magnitude. The study of precursors using earthquake instrumental data began in In 1949 Garm region of Siberia in Russia was devastated by an earthquake. The Russian scientists tried to investigate geological changes preceeding an earthquake. This study lasted for two decades. In 1971, the Russian scientists announced that the monitoring of the seismicity gives the important clues about the anomalous behaviour which will help to predict earthquakes. They found that the velocity of P and S seismic waves undergo change when rock in the potential Epicentral area is under stress. These changes were attributed to an effect called Dilatancy. They found premonitory changes in the ratio of seismic compressional velocity to the seismic shear velocity (Vp/Vs) prior to series of earthquakes of moderate size in Garm region Lynn Sykes and Yash Agarwal, Columbia University predicted an earthquake in 1973 using Dilatancy. Soviet seismologist S.A.Fedotov (5) put forth Seismic Gap theory as a precursor to predict impending earthquake. Kiyo Mogi from Japan ( 5) forecast few earthquakes in Japan using Seismic Gap theory. Studies have been carried out hoping that Patterns of seismicity exist which are characteristic of earthquakes. It is noted that micro January, 2011

67 earthquake activity preceeds some earthquakes usually as foreshocks. The patterns are of three basic types i) Activation ii) Quiescence iii) Migration of epicenters. Activation is almost identical to foreshocks; quiescence corresponds to expecting quiet before the storm. Wyss and Baer (1981) predicted a major earthquake on the basis of quiescence period. Migration of epicenters may be expressed as that of seismic gap in a seismically active region. A doughnut shaped pattern has been identified preceeding the Shimane earthquake of 1978 (. 6). The Chinese approach to earthquake prediction was more massive. In 1966, they launched war against earthquakes. In this attempt they engaged 10,000 trained earthquake specialists, 17 nodal centres, 250 seismic stations and 5000 observation points. They monitored well water level fluctuations, Radon content in water, changes in earth s magnetic field, tilt in the terrain and also behaviour of animals. Using all these precursors, Chinese could predict Heicheng earthquake of Feb.1975 and saved many lives. Rikitake has compiled several dozen possible precursors, both macroscopic and microscopic, identified from the analysis of large volume of observational data. He classified those precursors as i) Long term prediction ii) Medium term prediction iii) Short term prediction and iv) Imminent Prediction tools. Sub commission on Earthquake Prediction by International Association of Seismology and Physics of the interior has proposed forty precursors. Only five were judged as significant and of these five, two were of hydrochemical in nature and important to Reservoir Triggered Seismicity (RTS). H.K.Gupta classified 32 various precursors into six classes. These are:- i) Seismological Precursors: ii) Geomagnetic and Geoelectric Precursors:... 4 iii) Atmospheric/ Ionospheric Precursors:... 3 iv) Geodetic Precursors:...4 v) Geochemical Precursors:...6 vi) Biophysical Precursors:...2 A lot of research has been done in Triggered Seismicity especially in RTS. Observations suggest that Pore Pressure Diffusion, Quasi-Static and Quasi-Dynamic Nucleation process before the dynamic rupture of the main shock and Kaiser effect can be considered as an immediate earthquake precursor for small to moderate sized earthquakes. (7, 8). Methods of prediction based merely on precursory phenomena are purely empirical and involve many difficulties. The two important factors i) The state of the stress ii) Rock strength at Epicentral depths cannot be measured directly. This is the reason why prediction of earthquakes is normally unsuccessful. 4. Earthquake Precursory Studies in the State of Maharashtra, especially in Koyna area: The State of Maharashtra was seismically stable for many centuries. Therefore no attempts were made earlier as far as earthquake precursory studies are concerned. In Maharashtra, earthquake studies started in 1963 after the initiation of seismicity in Koyna project area. Central Water & Power Research Station (CWPRS), Pune was the main organization undertaking these studies. CWPRS instrumented the Koyna area with the help of Irrigation Department, Government of Maharashtra and tried to understand the causes of seismic activity. This study continued for two decades i.e. from 1963 to During these studies various precursory studies have been undertaken (9). These studies include i) Tilt of the Dam body and also terrain ii) Displacement of the body of the Dam. iii) Strain measurements iv) Telluric current studies iv) Seismomagnetic changes v) Seismic velocities Vp, Vs and ratio Vp/Vs vi) b values vii) Well levels in hot springs and their discharge There have been instances of premonitory variations in the above mentioned precursors preceding large and moderate earthquakes. Tilts, strain in deep underground rock, crustal displacements have been observed in Koyna earthquake region over a decade covering pre & post earthquake periods and their observations confirm their reliability for qualitative and quantitative premonitory indices. Tilt: Tilt in the Foundation of the Dam was observed significantly one or two years before the Koyna earthquake of Dec Ground tilt measurements using water tube tiltmeter located in the Dam gallery January,

68 showed sudden changes in ground tilt preceeding a moderate earthquake of Mag. 5.2 on 17 th oct.1973.few smaller earthquakes of M~ 4 have also shown similar premonitory changes in ground tilt. In the absence of continuity of the monitoring, this precursor was not used for further studies. Strain Measurements: Changes in Strain using Carlson type Strain meter in deep underground rock were observed for small earthquakes of Mag. 4.0 and above. The observed stress drop was 12 bars.but such strain meters can not adequately register earth stresses significantly for earthquakes at deeper levels. Telluric Studies: Telluric observations did not reveal any changes with seismic energy in the Koyna area. Seismomagnetic Changes: To detect premonitory changes in the piezo-magnetic field associated with Koyna seismic area, Proton precession Magnetometer observations were undertaken. Magnetometer located at Koyna did not show any premonitory changes related to the moderate size earthquakes. Seismic Velocities Vp, Vs, and ratio Vp/Vs: Premonitory changes in Vp/Vs were observed for few occasions for the aftershocks in the Koyna area. One of the significant premonitory changes in Vp/ Vs is observed for Koyna earthquake of 27 th June 1969, Magnitude 4.7. During subsequent periods, similar observations could not be observed for many other earthquakes of similar magnitude. As such it is difficult to draw any confirmatory inferences. Another interesting study is (10) P wave residual observations. About 800 earthquake events that occurred during Jan.1966 to June 1969 were studied. The study of the P wave residual at Koyna reveals that an increase of about 0.4 sec. in P residuals occurred in the source region of the Koyna earthquake. This anomalous change appears to have set in at least a year before the occurrence of the Main shock. The P residual studies appear to be equally well applicable for the analysis of earthquakes associated with strike slip faulting. The routine monitoring of P residuals can be regarded as an important tool for predicting earthquakes. b Values: The detail Koyna seismic data are available for the period Here, yearly b values i.e. Gutenberg-Richter relationships were studied. It is observed that the b values show significant changes in the pre and post earthquake data The pre earthquake values of b decreased slowly whereas post earthquake values of b increased sharply. Similar studies have been undertaken by NGRI in Bhatsa area for the period Decrease in the b values before the earthquake of Magnitude 4.9 and rise in the values after the earthquake is observed. The b value is a parameter that may change with time and the whole calculation is severely affected by data preparation, magnitude bias and data accuracy. Because of these limitations, b values can be taken as an indicator only of the seismic potential of the area. Well levels in Hot springs and their discharge: Monitoring of temperature and discharge of the hot springs aligned along the coast of Maharashtra have been taken for the period No conclusive correlation between Koyna seismicity and temperature of the hot springs and their discharge could be established. Interesting observation is at Killari. In the famous Neelkanteshwar Temple at Killari, the Shivling was often surrounded by water. But almost one year before the Main earthquake the water disappeared. Water again appeared after the Main earthquake. But such anomalies could not be identified as precursors to predict Time and Magnitude of the Main Killari earthquake. National Geophysical Research Institute, Hyderabad was also engaged in studying the Koyna seismicity from the beginning. Number of Research papers has been published on Koyna seismicity by NGRI scientists. Their detail investigations suggest that the triggering of earthquakes in the Koyna region is influenced by i) Rate of loading ii) The highest water levels reached iii) Duration of retention of high water levels iv) Kaiser effect (7). To understand the physics of the triggered earthquakes and possibly to forecast the medium size Koyna earthquakes NGRI concentrated their studies on Koyna region. Observing the fact that the Koyna earthquakes occur in a small area of 30km 20km and their focal depth is limited to 12 km and also earthquakes of M e 4.0 occur every year, a systematic research program is carried out January, 2011

69 for last two decades. Rastogi (8) Studied the rupture nucleation of few Koyna earthquakes and concluded that nucleation zone migrates towards North. The growth rate of nucleation zone varies from 0.5 to 10 cm/sec. The nucleation zone finally attains a length of about 4 to 8 km just before the days, probability of earthquake of M e 5 is enhanced at Koyna. Result: An earthquake of Magnitude 4.5 occurred on 30 th Aug Short term (one or two days before the event) prediction was not done. Attempts of forecast done by NGRI scientists are as below. Nucleation Observed on Forecasted on Earthquake occurred on Remarks First week of August 2005 Third Week of August 2005 for M ~ 5 30 August 2005 M 4.5 (MERI) M 4.8 (NGRI) Earthquake occurred on 20/11/2005(4.0) also. Nucleation observed Nov.2005 Not forecasted Nucleation observed Dec.2005 Not forecasted Nucleation observed Apr.2006 April May 2006 for M~ 4 10 October 2007 M ~ 4 21 May 2006 M 3.9 (MERI) M 4.2 (NGRI) 14, Oct.2007 M 3.1 (MERI) M 3.4(NGRI) Nucleation lasted for 380 hours, Not forecasted --- Not felt in koynanagar. Felt in Warnavati and Chikhali occurrence of Main shock. It is also observed that the growth of foreshock number with time suggests a quasi-static(slow increase of foreshock frequency) and quasi-dynamic (rapid increase of foreshock frequency) nucleation process before the dynamic rupture of the Main shock that can be considered as an immediate earthquake precursor for small to moderate sized Koyna earthquakes. In 2005, NGRI has put one step ahead and started real time earthquake monitoring and analysis which includes 7 to10 well established seismological observatories and many precursory studies like well level observations, Radon measurements and gravity studies etc. as multi parametric studies in Koyna area. Based on reservoir data and earthquake data, following forecast was made in September 2005 (11). Forecast: The forecast was made during third week of Aug.2005.There is a high probability of the occurrence of an M ~ 5 earthquake in the weeks to follow. If M ~ 5 earthquake do not occur till the end of Dec.2005 this be considered as a false alarm. If we succeed in identifying the nucleation when it is half way through we shall be able to make a short term forecast one or two days before the event. It was further noted that as Koyna area has experienced two earthquakes of M e 4.0 within January, 2011 This attempt is a remarkable development in the field of earthquake precursory studies. Since Aug. 2005, there are more than 60 earthquakes of magnitude M e 3.0. Out of those, identification of cluster of foreshock nucleation for 6 earthquakes is possible and forecasting in real time for two earthquakes is possible. Precursory changes of Stress Drop, Corner frequency are observed for five earthquakes of magnitude ranging from 4.1 to 4.7. This study was for the period 1994 to NGRI had also monitored well water level fluctuations in 21 observation wells for more than 10 years. Coseismic changes have been observed for local earthquakes of M e 4.3. Anomalous electron density variations are observed during the study of the F2 region of ionosphere during the period of Main Koyna earthquake. Comprehensive analysis of past One Hundred years of earthquake data reveals that earthquakes can be predicted using planetary configurations with fair accuracy with regard to Time, Location and magnitude. (Ref. ). Significant temporal changes in ä 13 C, carbon-13 isotope precursory studies are observed. 39

70 5. Conclusions: Various precursors have been studied and observed for the last forty-five years to predict Koyna earthquakes. But no precursor except Nucleation of foreshock cluster seems to be reliable for predicting impending Koyna earthquake. Looking at the above precursory studies in Koyna area, it seems that, in the forecasting attempts the use of real time analysis of Stress Drop, Corner frequency, Deep well level observations, b values, Vp/Vs or Tp/Ts, Changes in P wave residuals along with Nucleation of foreshock cluster will enhance the prediction probabilities of earthquakes in Koyna area. 6. References: 1. Report of The Experts committee on seismology, Irrigation Dept., Govt. of Maharashtra, Mumbai, (1995). 2. Lele V.S., Tambat S., Lele Y.S., (2003). Earthquakes, References from the Rigveda to the Rajatarangini, Pub by Sanskrit Sanskriti Samshodhika, Jnana Prabodhini, Pune. 3. Iyengar R.N., Earthquakes in ancient India 4. Guha S.K., Koyna Earthquakes (1974), Central Water and Power Research Station, Pune 5. Hemmady A.K.R., Earthquakes, National Book Trust, India (1996). 6. Scheidegger A.E., Thirty lectures on Seismicity (1981), Cent. Water & Power Research Station, Pune 7. Gupta H.K.,(2005)., Artificial water reservoirtriggered earthquakes with special emphasis at Koyna, Current Science, Vol.88, No Rastogi B.K., Mandal P. Foreshocks and Nucleation of Small to Moderate sized Koyna Earthquakes (India), Bull. Seism. Soc..Am., 89, Guha S.K. (1974).. Koyna Earthquakes (1963 to 1973), CWPRS, Pune 10. Saxena A.K., Gaur V.K., Khatri K.N., P- Residual studies around Koyna Dam Region, Maharashtra, India, Department of Geology, University of Roorkee. 11. Gupta H.K. (2005). An earthquake of M ~ 5 may occur at Koyna, Current Science, Vol. 89, No Rastogi, Precursory changes in source parameters for the Koyna-Warna earthquakes, Geophysical Journal International, Vol.158, Issue 7, pp Chadha, R.K., Pandey, Ajeet P. and Kuempel H.J., (2003), Search for earthquake precursors in well water levels in a localized seismically active area of Reservoir Triggered Earthquakes in India: Geophys. Res. Lett., v. 30 (7), p Chadha, R.K., Kuempel H.J., Shekar M., Reservoir triggered Seismicity (RTS) and well water response in the Koyna-Warna region, India., Tectonophysics,Vol.456, Issue 1 to2., Sharma K., Das R.M., Dabas R.S., Pillai K.G.M., Garg S.C., Mishra A.K., (2008). Ionospheric Precursors observed at low latitudes around the time of Koyna earthquake, Advances in Space Research,.42 (7), Venkatanathan N. (2005). Planetary configuration: Implications for earthquake prediction & occurrence in Southern peninsular India. J. Ind. Geophys. Union,.9,(4), Sukhija B.S., Reddy D.V., Najabhushanam P., Significant temporal changes in ä 13 C of ground water related to reservoir triggered seismicity. Seismologic Research Letters, Seismological society of America, Mar Reddy D.V. Radiation Measurements, Vol.45, Issue 8, Sep.2010 pp January, 2011

71 S5_C10 Earthquake pre-cursory studies in Koyna- Warna region, India: Some vital observations D.V. Reddy and P. Nagabhushanam (National Geophysical Research Institute (Council of Scientific and Industrial Research), Uppal Road, Hyderabad (India). To capture the seismogenic precursory signatures in real time, exploratory experiments involving hydrochemical and soil gas Radon (Rn) measurements in Koyna Warna region, India, were initiated in Periodical groundwater sampling has been made from 12 bore wells out of 21 (90 to 250 m deep) drilled for the pore pressure studies and two hot springs, besides surface water sampling from Koyna and Warna reservoirs. During the study period ( ), it is observed that the Govare well has been unique in showing precursory chemistry changes in response to the seismic events (Me 5). The Govare well recorded maximum changes in Chloride, Sulphate, Fluoride and 18 O isotopic ratio (d 18 O) during the 14 March 2005 earthquake (M 5.1). Since August 2006, its precursory chemistry has gradually increased, with decreasing d 18 O, to middle of The changed chemistry has shown no relation with groundwater recharge. A model is proposed to account for the precursory chemistry changes, wherein mixing of two chemically different waters takes place facilitated by micro fractures generated due to seismic stress. Projection of the precursory linear chemical changes observed till March 2009, to the level recorded during 2005 earthquake (M 5.1) has shown the time window for an impending Me 5 earthquake. The window was 2012/13 or 2011/12 from the August 2006 datum. The projection based on exponential increase, advanced the time window to 2010/11. The projected earthquake happened on 12 December 2009 (M 5.1), while studies were still going-on. Based on Koyna s 40 year earthquake history, the statistical estimate of recurrence interval of earthquakes (Me 5) in Koyna is 5 year, which lends support to the projected seismic event. Additionally, hourly monitoring of electrical conductivity (EC) of Govare well water and the soil gas radon measurements at 60 cm depth in real time January, 2011 have provided strong precursory signatures in response to two earthquake (M 4.7 on , and M 5.1 on ) that occurred in the study region. For M 5.1 earthquake, the EC recorded preseismic (~40 hours earlier) and also post-seismic perturbations (~20 hours after), but for the M 4.7 earthquake, it had only post-seismic signature (8 days after). Another precursor, the Rn had shown preseismic increase ~20 days in advance for both the earthquakes, while the co-seismic signature was less by 50% and 30% respectively from their peaks. All the observed precursory signatures are attributed to the phenomenon of opening and closing of micro fractures due to seismic stress. On-line monitoring of these two parameters may be useful to check the entire chemistry changes due to earthquakes, and it may help to forecast the impending earthquake(s). S5_C11 Detection of possible precursors of the 2010 Chile earthquake using superconducting gravimeters and broadband seismometers records Jun Yi 1, Wen-Bin Shen 1,2 ( 1 Department of Geophysics, School of Geodesy and Geomatics, Wuhan University, China, 2 Key Laboratory of Geospace Environment and geodesy, Wuhan University, China. Scientists have great interest in finding precursors of large earthquakes. In this study we focus on detecting possible precursors of the Mw 8.8 Chile earthquake event occurred on 27 February 2010 based on both the Superconducting Gravimeters (SGs) under the Global Geodynamic Project (GGP) and the Broadband Seismometers (BBSs) supervised by the Incorporated Research Institutions for Seismology (IRIS). Due to the non-linear and non-stationary characteristics of both the SG and BBS data, we use the Hilbert-Huang Transform (HHT) to analyze the records, in which the Ensemble Empirical Mode Decomposition (EEMD) is adopted to obtain intrinsic mode functions (IMFs) and timefrequency-energy spectra. Analysis of the records in quiet periods provides quite uniform timefrequency-energy distributions located within two frequency windows, taken as background spectra. Then, we analyze 1-Hz data recorded at about ten 41

72 SG stations and 20-Hz data recorded by more than ten BSS stations covering several days before the Chile event, and we find that almost half of the records show that there are anomalous signals prior to the 2010 Chile event, which might be the possible precursors. The present study is preliminary and further investigations are in progress. This study is supported by Natural Science Foundation China (Grant No ). S5_C12 Seismic Acoustic Emission (SAE) as an earthquake precursor G. Suresh and R. S. Dattatrayam (India Meteorological Department, Ministry of Earth Sciences, Lodi Road, New Delhi ). Seismic Acoustic Emission (SAE) produced in the earth s crust play an important role in understanding the tectonic stress regime of a region. The abrupt changes in SAE measured in deep boreholes are related to stress state variation in a local crustal volume before a possible earthquake. These changes are a direct result of disturbances in the crust and can serve as reliable short term precursors of earthquakes (Belyakov et al. 2002). In order to carryout continuous measurements of SAE in India, India Meteorological Department (IMD), under an Indo-Russian collaboration (Integrated Long Term Program of Cooperation of Department of Science & Technology), set up a borehole seismic acoustic recording system comprising of tri-axial magnetoelastic acoustic geophone (Model No. MAG-3B, manufactured by Russian Academy of Sciences) in October, The sensors are deployed in a water tight and re-usable borehole at a depth of about 100m at Ridge Observatory, Delhi. The sensor is based on magneto-elastic conversion of the rate of change of inertial force to an electrical signal measured in a broad frequency range of 20Hz to 2000Hz. The data is recorded in one-third-octave acoustic frequency bands centered at 30, 160, 500 and 1200Hz in a 6- channel 12-bit A-D converter installed in a PC. The signals in each band are averaged for 1 minute and digitized before storing in the memory. The equipment is observed to be sensitive to local earthquakes of magnitude 4.0 and above occurring within a distance of 100km from the observatory. The system has recorded a local earthquake of magnitude 4.5 on 25 th November, 2007 with its epicenter at a distance of 16.8km from the Ridge observatory. It was observed that the signal amplitude progressively increased by eight folds, 30 min prior to the event in the 30Hz and 160Hz frequency bands in comparison to higher frequency bands. However, the data does not show any significant increase in the signal amplitude for several local earthquakes of magnitude less than 4.0, which have occurred within a distance of 100km from the observatory. Further, the long-term variations in the SAE indicate some correlation with Sun-Moon tides. It is also observed that cultural noise has a significant effect of masking the signals, particularly for the low magnitude events. It would be useful to deploy a network of at least three such systems each in seismically active areas, such as NW Himalaya, NE India etc., in a site which is free from industrial and cultural noises, to be able to make the best use of the recorded data for identifying precursory signals. An attempt has been made in this paper to discuss the salient features of the borehole system along with some results. S5_C13 Study of multi-parameter gas-geochemical precursor signals of a distant earthquake recorded simultaneously at two thermal springs in India. H. Chaudhuri 1 ( D. Ghose 1, R. K. Bhandari 1, P. Sen 2, and B. Sinha 1 ( 1 Variable Energy Cyclotron Centre, 1/ AF Bidhannagar, Kolkata , India, 2 Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata , India) Investigations dealing with the forecasting techniques of natural calamities like cyclones, thunderstorms, floods, earthquakes and tsunamis have become an important research trend. Among these natural hazards, earthquakes and tsunamis are the most destructive, in terms of loss of life and destruction of property. The present paper deals with the technique of short term earthquake precursors using seismo-geochemical monitoring. Continuous He and 222 Rn along with gamma dose rate were simultaneously monitored for pre-seismic signatures at two thermal springs in India. The monitoring stations are placed in dissimilar geological January, 2011

73 environments and in different seismic zones of the country and are separated by a distance of 1612 km. One of the monitoring stations is located at the thermal spring site at Bakreswar which lies in the eastern part of the country in a moderate risk zone - seismic zone III. The other monitoring station is situated at the Tatta Pani thermal spring site which falls in the north-western part of the country in a high risk zone - seismic zone IV. Bakreswar is close to the extinct (115Ma) Rajmahal volcanics of the Chotanagpur gneissic complex in West Bengal while the other spring at Tatta Pani is located in a non-volcanic geothermal area that lies within the mountain folds of Jammu & Kashmir, situated in proximity to the Main Boundary Thrust (MBT) of the Lesser Himalayas. In this paper, we make a cross correlation study, using nonlinear technique, of the simultaneously recorded geochemical data from the two thermal springs. The anomalous fluctuations in the spring gases observed during the period December 24-27, 2007 at both the thermal springs may be correlated to the distant (~ 1000 km) China earthquake of magnitude M=6.3 that occurred on January 09, Based on the obtained sequence of data points we attempt to make a time series analysis to relate magnitude and epicentral distance through statistical methods and empirical equations related to the zone of influence. These geochemical anomalies recorded at distant sites appear to be a potential tool to deal with the commonly debated question of earthquake precursors. Keywords: Thermal spring, geochemical anomaly, helium, radon, gamma, time series analysis, nonlinear technique, earthquake precursors S5_C14 Predictability of Valsad Earthquake Swarms Gujarat, India H.N.SRIVASTAVA and S.N.BHATTACHARYA (Formerly in India Meteorological Department). D.T.RAO and S.SRIVASTAVA (Gujarat Engineering Research Institute, Vadodara). Valsad district in south Gujarat near the western coast of the peninsular India experienced earthquake January, 2011 swarms since early Seismic monitoring through a network of microearthquake seismographs showed a well concentrated seismic activity over an area of with the depth of foci extending from 1 to 15 Km. A total number of earthquakes were recorded during March 1886 to June The daily frequency of earthquakes for this period was utilised to examine deterministic chaos through evaluation of strange attractor dimension and Lyapunov exponent. The low dimension of 2.1 for the strange attractor and positive value for the Lyapunov exponent suggest chaotic dynamics in Valsad swarms with at least 3 parameters for earthquake predictability. The results have also been discussed to indicate differences in chaotic mechanism between interplate and intra plate earthquakes in the Indian region. S5_C15 The analysis of microseisms before the 2008 great Wenchuan earthquake Xiao-Guang Hao, Xiao-Gang Hu*(Key Laboratory of Dynamical Geodesy, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, We investigate microseisms recorded by broadband seismographs in mainland of China before the 2008/ 05/12 great Wenchuan earthquake. Our results indicate that the microseisms consist of two main parts which have totally different dynamical characters. The part in the frequency band of 0.2~0.25Hz is related to a typhoon named Rammasun, which was evolving from 9 May to 13 May 2008 with its maximum at 11 May. This type of microseism is strong at seismic stations near the coastline of China but weak at stations in the inland of China. Another one in the frequency band of 0.12~0.17 Hz bears no relation to Rammasun. The energy of this non-typhoon microseism has slowly increased since May 10, but it starts a dramatic increase at 10 hours before the earthquake and reaches the maximum just before the great earthquake outburst, and it is strong near the epicenter of the earthquake but comparatively weak in the coastline of China and Western China. 43

74 We locate sources regions for the typhoon-related microseism and the non-typhoon microseism by the source scanning algorithm, respectively. The results show that the typhoon-related microseism is generated at coastal region when swells from Rammasun impact shorelines, but the source region of the non-typhoon microseism are distributed around the epicenter of Wenchuan. S5_C16 Multi-Parametric Geophysical observations at Ghuttu, Garhwal Himalaya: Radon component V.M.Choubey( B.R. Arora, Naresh Kumar and Leena Kamra (Wadia Institute of Himalayan Geology,33, General Mahadeo Singh Road, Dehradun , India) The Multi parametric geophysical observatory (MPGO) established at Ghuttu in Garhwal Himalaya designed to study the earthquake precursors in an integrated manner. The observatory is equipped with Overhouser magnetometer, flux gate magnetometer, superconducting gravimeter, ULF-VLF magnetometer, radon & water level monitoring system, seismographs and GPS system. A 68 m deep borehole, penetrating into the water table is incorporated for taking continuous radon monitoring at two depth points from the surface. One measurement is taken at 10 m (in the air column) and the second one at 50 m (within water column) depths. Besides radon concentration, air temperature, water temperature, atmospheric pressure, rainfall and water level fluctuations are also recorded in the borehole site with sampling interval of 15 min. The continuous time series of radon variation along with other environmental parameters of 3 years (2007 to 2009) shows a rich and complex pattern of temporal changes in radon including well-defined seasonal and diurnal variation. The radon data is nonstationary and exhibit non-constant variance with very low changes in background level in winter and highly fluctuation in summer. The radon measurements at 10m depth show a well-defined diurnal pattern in concentration that is having minimum value in the early morning and maximum in the afternoon. The analysis of three years data indicates that this daily variation is well correlated with atmospheric temperature. Examination and correlation of radon with environmental factors has revealed that when atmospheric temperature is less than that of water temperature in the borehole, the variation from background level is negligible. However, when the atmospheric temperature surpasses the borehole water temperature, peaks diurnal pattern are observed in summer. Although the similar higher atmospheric temperature exists during rainy season also but following continuous rainfall, once the soil/rocks are saturated with water, radon concentration show fair stability with high value than average. Long pauses in rainfall give jerky variability during rainy season with no clear pattern of daily variation. The recorded radon data strongly suggest that the atmospheric temperature and rainfall influence the variability of radon emanation therefore these anomalies has to be removed first while searching precursory signature in this continuous radon data. S5_P1 Thermal and ionospheric anomalies associated with the Haiti earthquake of January 12, 2010 Suryanshu Choudhary ( Shivalika Sarkar and A.K.Gwal (Space Science Laboratory, Department of Physics, Barkatullah University, Bhopal , India) This paper examines the anomalous variations of atmospheric and ionospheric parameters observed around the time of a strong earthquake (Mw 7.0) which occurred in Haiti region ( N, W E) on 12 January Sea Surface temperature (SST) data obtained from NOAA AVHRR satellite has been used to study the thermal anomalies associated with this great earthquake. Wavelet analysis of the NOAA AVHRR data shows decrease of the sea surface temperature several days before the Haiti earthquake. In addition we have also used the DEMETER satellite data to study the plasma parameter variation during the Haiti earthquake. Increase of the plasma parameters has also been observed one day before the occurrence of the main shock. Statistical processing of the DEMETER data, together with SST data demonstrates the possibility of an early warning of an impending strong earthquake January, 2011

75 S5_P2 Earthquakes in Uttaranchal Himalaya, India. ARUN K SHANDILYA ( ANURAG SHANDILYA (Department of Applied Geology, Dr. Hari Singh Gour University, Sagar (M.P.) INDIA). On the basis of the seismic records of seismic events in Uttaranchal a review of the events have been done and probabilities of the earthquake has been workout in the part of Garhwal-Kumaun- Himalaya in Uttaranchal. In the southern part of outer Himalaya thrust zones are expected to produce a long term probabilities of large earthquakes of magnitude more than 6, on Richter scale which have on and average 5 to 20 mm reactivation and neotectonic upliftments along the shear zones. These zones have estimated to have future probabilities of earthquakes on these areas which are based on the historical seismic records, the long term slip rate and the displacement caused by the previous seismic events. The historical records of seismic events in these part of the Himalaya have the earthquake intensities varying from 4 to 6.0 on Richter scale in the geological past. The Kangra earthquake (1905) was recorded more than 7.0 Richter scale, Garhwal Earthquake (1883), (6.0), Uttarkashi earthquake (1920), 1991 (5.6, 6.8) respectively, Chamoli earthquake (1999), 6.5 and the Dehradun earthquake of (1970). The approach followed for calculations of probabilities employ the estimated recurrence times with a model that assumes probability increases with elapsed time from the large earthquake on the fault/ thrust zone areas. Through the calculated probabilities the estimated natural disaster/hazards in the newly born state of Uttaranchal in Himalayan belt can be reduced. Key Words- Himalayan thrust, Recurrence time, elapsed time, rupturing S5_P3 Low Field Magnetic Measurements: A Modern Tool for Prediction of Earth-Quake By Dr Rajeev Vaghmare (GRIIC, GERMI Gandhinagar). On and average an earth s magnetic component at the equator of the earth is about 40,000 gamma. This value of earth s magnetic field changes from place to place on the earth. Low field strength magnetometer is a useful tool for sensing the changes of the EARTH s MAGNETIC Field with the internal changes in the earth s crusts. The minor changes to the tune of +/- 1.0 gamma, field strength can lead to conclude the prediction of the EARTH-QUAKE at least THREE hours before its actual occurance. These kind of low filed strength measurements are done using M/S BARTINGTON make MAG01 magnetometers, which can measure the changes in the earth s magnetic component at a given place And further a correlation can be established using the changes in Magnetic Filed as function of intensity of an earth-quake likely to struck at a given place. The interesting fact is that the empirical equations can be established between CHANGE in MAGNETIC FIELD and the Intensity of the Earth Quake. The rate of the change of the magnetic values can also be extrapolated to the time of the occurance of the EARTHQUAKE at the given place. Concludingly, the low field strength measurement technique can act as very useful tool for the EARTH QUAKE predictions. Acknowledments # The Author is thankful to GERMI Authorities for the kind permission accorded for submitting the abstract to International Symposium on The 2001 Bhuj Earthquake and advances in Earthquake Science being held during January January,

76 S5_P4 Foreshock clustering as Precursory Pattern for the Kachchh Earthquakes in Gujarat, India. Sandeep Kumar Aggarwal ( B. Sairam, Santosh Kumar and B.K.Rastogi (Institute of Seismological Research, Village Raisan, Gandhinagar) As the aftershock activity to M5 level is continuing in the rupture zone of 40 km X 70 km, we studied clustering pattern of aftershocks of 2001 Mw 7.7 Earthquake in Kachchh. The activity has also expanded to nearby faults. Presently clustering occurs along North Wagad Fault and Gedi Fault. As the seismicity is monitored by dense network of more than 20 broadband seismographs in Kachchh active area of about 60kmX60km, the earthquake locations are precise and it has been possible to observe foreshocks clustering prior to eight mainshocks of Mw 3.8 to 4.5 during 2007 to 2009 with the following details: Numbers of Foreshocks in different cases are 4 to 70 (with two or more shocks of M e 3.0). Radius of Clusters is 4 to 25 km. Duration of Clusters is 7 to 25 days. Quiescence of 1 to 6 days is observed for six cases. The precursory observation found is that if the shocks cluster at depth of 15 km to 30 km along with 2 to 7 shocks of Magnitude e 3.0, a Mainshock of M4 to 5 occurs. In one case of mainshock along Gedi Fault (Mw 4.1 on 15 Apr 2008) the focal depth of the Mainshock and foreshocks are km. It has to be mentioned that similar clustering observed at other times was not followed by M~4 mainshocks. The pattern of clustering appears to be a useful precursor, as one M4.5 mainshock on September 5, 2009 was in-house predicted a day in advance from cluster model as there were 7 foreshocks of M 3 to 3.7 and 60foreshocks of M 0.5 to 2.9 in 40km X 20km area during 10-days period followed by a day s quiescence. Key word: Clustering, Seismicity, Quiescence, Foreshock, Mainshock, Kachchh S5_P5 Status of Superconducting Gravimeter and MPGO Network of Kachchh. Arun Gupta ( Rashmi Pradhan*, M.S.B.S. Prasad and B.K. Rastogi (Institute of Seismological Research, Raisan, Gandhinagar , Gujarat. *Ministry of Earth Sciences, New Delhi) A very sensitive dual sphere superconducting gravimeter (SG-055) was installed on March 01, 2009 at Badargadh (BG) in Kachchh (Lat 23.47ºN, Long ºE). This site is seismically active and free from cultural noise. It is surrounded by Rann of Kachchh (salty waste land) in three directions (N,E and W) at about 20-30km distance and Ocean coast in S at about 50-80km distance. After removal of spikes and offsets, continuous record of about one year gravity changes show the dominating effect of solid earth tides, ocean loading and atmospheric pressure. Available rainfall and geohydrological data do not show significant effect on gravity records. Earth s free oscillations excited by some large earthquakes are well recorded on SG. Besides some large and moderate earthquakes, coseismic changes have also been observed during earthquakes of Mw e 4 within periphery of 80 km from Badargadh. SG was installed as a part of Multiparametric Geophysical Observatory (MPGO) instruments and SG data will be supplemented by several other parameters. Institute of Seismological Research (ISR) has established a network of four MPGOs at Bhachau, Vamka, Desalpar and Badargadh in Kachchh which is operational from March 2009 and fall in the aftershock zone of 2001 Bhuj earthquake (Mw 7.7) for earthquake precursory research. Several seismological / geophysical / geochemical parameters are under continuous monitoring through other MPGO instruments like Very Broad Band Seismometer (VBBS), Strong Motion Accelerometer (SMA), Global Positioning System (GPS) and radon recorders at all the four sites. Borehole strainmeters will be installed shortly at three sites. Fluxgate magnetometer is installed at Desalpar and Vamka. Further, water level recorder is installed at Desalpar. Five water level recorders will be installed shortly in these areas. ULF/VLF induction coil magnetometer, Declination/inclination magnetometer, overhauser magnetometer and helium recorders are to be purchased. Some of the preliminary results will be presented and discussed in the meeting January, 2011

77 S6: Seismic Wave Propagation, Soil Amplification and Basin Effects Convener : J.P. Narayan THEME Significant differences in structural damages in basins as compared with the surrounding exposed rocks or even in a basin itself from place to place have been observed during the past earthquakes. The theoretical studies have revealed that assessment of soil amplification and resonance frequency for layered soil deposit in basin using an empirical relation is erroneous. The recent researches have also revealed that basin-edge, shape and size of basin and the basement topography play an important role in altering the ground motion characteristics. In light of above, the research papers dealing with the following aspects are invited for presentation and discussions during the symposium. a. Assessment of soil amplification and resonance frequency using experimental techniques like standard spectral ratio method, horizontal to vertical spectral ratio method and H/V ratio method. b. Assessment of soil amplification and resonance frequency in a basin using analytical and numerical techniques. c. Numerical and analytical methods for simulation of seismic wave propagation. d. Seismic microzonation of basin. e. Assessment of effects of basin geometry and surface topography on the ground motion characteristics S6_C1 A Possibility of Site Effects due to the past Earthquakes at Anjar, Gujarat State, India Fumio Kaneko 1 B.K.Rastogi 2, A.P.Singh 2 B.Sairam 2 Sudhir K. Jain 3 Shukyo Segawa 1 Jun Matsuo 1 ( 1 Oyo Internationa Corporation, Tokyo, 2 Institute of Seismological Research, Raisan, Gandhinagar, Gujarat (India) , 3 IIT, Gandhinagar) It is well known that site effects contribute to damage due to earthquakes for a long time. This was for the first time pointed out at Anjar for the 1819 great Kachchh earthquake and then again for the 1956 Anjar earthquake and the 2001 Bhuj earthquake. For check this effect by detecting site response characteristics and soil conditions, single H/V microtremor (ambient vibration) survey, MASW (shallow seismic surface wave exploration) and earthquake observation were conducted at damaged, less- and non-damaged locations. As the result, the single H/V microtremor survey and the earthquake observation showed a clear difference between damaged and non-damaged locations. Also, the January, 2011 simple response analysis using the estimated soil structures due to the MASW survey supported the results. Thus, in Anjar, site effect for seismic damage can be suggested. S6_C2 Determination of Site Amplification in the Northern Iran from Inversion of Strong-Motion Records B. Hassani, H. Zafarani (International Institute of Earthquake Engineering and Seismology, E- mail: The amplification of strong ground motion at sites in the Northern Iran is determined using the generalized-inverse method. Site-amplification estimates are determined at 60 strong-motion sites that provided horizontal-component records from 45 earthquakes of magnitude M4.0 to M7.3 in the region. The inverse problem was solved in 20 logarithmically equally spaced points in the frequency band from 0.4 to 15 Hz. To obtain a unique inverse solution, a frequency-dependent site amplification as a constraint was imposed to two reference site responses. So, the site response estimates are determined relative to the spectral level recorded at two selected reference sites. Average site response values were correlated to the average shear wave 47

78 velocity in the uppermost 30m, in high and low frequency bands. The peak frequencies of site amplifications estimated by the generalized inversion method were coincided with those of horizontal tovertical (H/V) spectral ratios for the S-wave portion of records. However, due to the shortcomings of the H/V ratio technique, a perfect matching in amplitude was not obtained. For two frequency bands, the average of site response spectra were computed and related to the shear wave velocity in logarithmic scale. It is a good idea to plot the residuals against the independent variables (magnitude and distance) to see if they show atrend. The predicted Fourier spectral amplitudes agree well with available Iranian strongmotion data, as evidenced by the nearzero average of differences between the logarithms of the observed and predicted values (residuals) for all frequencies and the lack of any significant residual trends with distance and magnitude. Keywords: Generalized inversion, Site response; Northern Iran. S6_C3 Estimation of Dynamic Properties of Lucknow Soil T.G. Sitharam (Professor, Department of Civil Engineering, Indian Institute of Science, Bangalore, India ; S. M.Patil (.Research Scholar, Department of Civil Engineering, Indian Institute of Science, Bangalore, India ; In critical task of providing the solutions to earthquake geotechnical engineering problems the dynamic properties of soils play a major role in the regimes of linear, intermediate and high levels of strain. For these above considerations of importance, in this paper we are estimating the Shear modulus (G) and damping ratio (D) variations as a function of applied strain (ã) for soil collected from the specific sites of Gomathi river bank in Lucknow city. This Lucknow soil is studied as a sand silt mixture by taking into account the effect of added non plastic fines on the dynamic behavior. The geographical location of the Lucknow city in the Indo Gangetic basin with loose alluvial deposits and its vulnerable distance from central seismic gap (Garhwal-Kumoun Himalaya) has made Lucknow a place of prominence for seismic liquefaction studies. Here the soil is tested at constant relative densities (RD) for different silt contents (%) in cyclic triaxial testing equipment at stress controlled conditions and it is observed that the limiting fines content (LFC) affects the shear modulus (G) and damping ratio (D) by proportionately decreasing with silt content till LFC is reached and thereafter it shows an approximate constant behavior. S6_C4 Liquefaction Susceptibility of Lucknow Soil T.G. Sitharam (Professor, Department of Civil Engineering, Indian Institute of Science, Bangalore, India ; S. Patil (Research Scholar, Department of Civil Engineering, Indian Institute of Science, Bangalore, Inida ; Ravi S. Jakka (Post-Doc, Centre for infrastructure, Sustainable Transportation and Urban Planning (CiSTUP), Indian Institute of Science, Bangalore, India ; Seismic microzonation of urban centers is an effective mitigation tool to minimize seismic hazards, particularly for those cities which are located in high seismic zones. Lucknow is a fast growing urban center and is situated very close to the Himalayan central seismic gap, where a very high magnitude earthquake event is anticipated. Seismic microzonation studies require the evaluation of liquefaction susceptibility of local soils to assess the local site effects on the associated geotechnical seismic hazards. Here in this paper, studies carried on the liquefaction behavior of Lucknow soils using stress controlled cyclic triaxial tests are presented. Effect of variation of fines content on the liquefaction resistance of Lucknow soil is evaluated based on the constant global void ratio approach. Results showed that limiting silt content plays an important role in the cyclic resistance of the soils. Initially, as fine content increases, the liquefaction resistance of the soil is decreased till the limiting silt content, and thereafter further increase in silt content increases the liquefaction resistance of the soil. It is observed that these variations on the liquefaction resistance of soils are closely related with variations in the relative density. For a given silt content, cyclic January, 2011

79 resistance increases with increase in relative density (ie. decrease in void ratio) of the sand-silt mixture. S6_C5 Site Characterization: Which Dataset to Use? Manish Shrikhande ( and Susanta Basu (Department of Earthquake Engineering, Indian Institute of Technology RoorkeeRoorkee INDIA); A set of mainshock and aftershock data following Chamoli earthquake of March 29, 1999, recorded at a single station has been studied. Particularly, the utility of the use of aftershock/weak motion data for site characterization in seismic microzonation studies is investigated. The analysis of mainshock and aftershock data indicates that the spectral shape and amplification is quite different during mainshock and aftershock. This, in turn implies that the use of weak motion/aftershock records may lead to erroneous conclusions regarding the expected ground motion during a strong earthquake. S6_C6 The Ground Effect of the SKOPJE 1963 earthquake, Again Apostol Poceski (Fac. of Civil Eng.Univ.Sent Cyril & Metodi, Skopje, R.Macedia (now retired) The earthquake was of magnitude 6.0, the focus on about 8 km of the city center, of shock type shallow, short duration, main portion probably not more than 2-3 sec. There was amplification possibly up to 3 times, maximum acceleration up to 50-60% g (at that time 1966, unbelievable). The damage distribution was explained in terms of the seismic response of surficial soil layer. There exists a generally good correlation between the distribution of damage, the thickness of the surficial layer, and the predominant period of microtremors. The most heavily damaged region is covered with about m. alluvium and the predominant period is around 0.36 sec. The greatest destruction was recorded along a belt with the fault through the middle of the city, fig.1 (right of PL). However, to certain distance heavy destruction was recorded on the shallow alluvium side January, 2011 Fig.1 Cross section south-north through the city center, ALT alluvium terrace (gravel with send); PL Pliocene (gravel, send with clay), conglomerates, marl); MPL Mio-Pliocene (mostly marl) On the left side of fig.1, along the slopes of the mountain Vodno (1050 m), there are several remains of the flow of the river Vardar. Vodno rises and the valley sinks (witness of the intensive tectonic movements in the old geology times). Over the right side of fig.1 is the old town, soft soil proluvium and clay, with rare contemporary buildings in that time. Further north, km is mountain, over 1000 m over see level; at the city center it is about 250 m. The figures are drawn on the base of data gained by borings. Thousands of borings throughout the city and around it, starting from about 6 meters deep, up to several hundreds, have given useful data, about the geology of the ground and geotechnical characteristics. In addition, by application of geophysical methods and seismic prospecting, the geology up to thousands meters was obtained, including the velocity of the seismic waves. Further more, the micro tremor investigations were carried out, according to the K.Kanai method. The data gained by all of these investigations were base for derivation of amplification coefficients for particular regions. The method of analysis was that of Kanai-Tanaka. The amplification distribution determined in that manner, in general, was similar to the damage distribution. After the earthquake, in , series of after-shock measurements by seismographs were carried out, at several points with different characteristic of the soil. The maximum amplification was 2.97 at point on 40 m. thick alluvium surficial layer. This is close to m in the most damaged region, fig.1, right of the fault. 49

80 (There were not records around these thicknesses). The main purpose of the last investigations was seismic microsoning, but it seems not quit successful. Unfortunately, any micro-zoning did not take place. Fig2 Longitudinal section west, north west east, south east through the center; at both ends- Faults, deep sinking, in the west more than 120m, in the east almost 200 m., transverse faults at both ends also. On small hills around the city, on the surface appears neogen (MPL), which is base-rock for big portion of the valley, with dominant period of 0,36sec. This could be the dominant period of the incoming seismic waves, same as the period of the most damaged region. It means vibration close to resonance and big amplification of the vibrations on the surface. In addition, there were many buildings of 3-4 stories, with natural periods close to that one - destroyed. By analysis of several damaged buildings, it was concluded that maximum seismic forces could have been equivalent to acceleration of 50-60%g. In the case of greatest distraction around the fault at the middle of the city, fig.1, the left side with shallow alluvium, the dominant period is of the order of 0.15 sec. The right side, of deep alluvium, has dominant period of micro vibration of the order of 0.36sec. So, there had to be like vibrations out of faze of two portions, or precisely spiking shear forces occurred, and cutting of buildings. On the portions of the city, at the ends of fig.2, there were not many buildings and at that time not attention was given. But now, on the region east of the figure, many tall buildings are built, just over the faults. In addition, in progress is design of several very tall buildings, minimum 150 meters high, on hundreds meters thick, with water saturated alluvium! Construction of buildings continues like nothing has happen, the earthquake is forgotten. Nobody wants to know about any investigation, even those whose job it is supposed to be. A silly question arises: what is the meaning of the research work by many scientists? I am saying this because similar problems may be in many other countries. S6_P1 Attenuation of Coda Waves of Local Earthquakes In the Northeastern India Alok Kumar Mohapatra ( - Tele: ) and William Kumar Mohanty (Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, West Bengal, India ) The attenuation of coda waves (Q c ) have been estimated for the Northeastern India, using ten local earthquakes from April 2001 to November The single back scattering attenuation model is used to estimate frequency dependent values of Coda Q (Q c ) at six central frequencies 1.5 Hz, 3.0 Hz, 6.0 Hz, 9.0 Hz, 12.0 Hz, and 18.0 Hz. Earthquakes with magnitude range from 3.8 to 4.9 have been taken into account. These earthquakes are well recorded on the broad band seismic observatory at Cherrapunji, Barapani and Bahiata in the Northeastern India. In the present work the Q c value of local earthquakes are estimated to understand the attenuation characteristic and tectonic activity of the region. Based on a criteria of homogeneity in the geological characteristics and the constrains imposed by the distribution of available events the study region has been divided into three zones such as the Tibetan Plateau Zone (TPZ), Bengal Alluvium and Arakan- Yuma Zone (BAZ), Sillong Plateau Zone (SPZ). The mean values of frequency-dependent coda Q varying from at 1.5 Hz to at 18 Hz. Average Q c value obtained by analysing coda waves of ten local earthquakes is 198 f This relationship varies from the region to region such as, Tibetan Plateau Zone (TPZ): Q c = 226 f 1.11, Bengal Alluvium and Arakan-Yuma Zone (BAZ) : Q c = 301 f 0.87, Sillong Plateau Zone (SPZ): Q c = 126 f The above results indicates Northeastern India is seismicaly active but comparing of all zones in the study region the Shillong Plateau Zone (SPZ): Q c = 126 f 0.85 is seismicaly most active. Where as the Bengal Alluvium and Arakan-Yuma Zone (BAZ) are less active and out of three the Tibetan Plateau Zone (TPZ) is intermediate active. This study may be useful to determine the source mechanism and the seismic hazard assessment. Key words: Coda wave, Lapse time, single backscattering model and Northeastern India January, 2011

81 S6_P2 Spectral Decay Parameter (κ) using the Accelerograms of the Earthquakes in Himalaya Renu Yadav ( Kavita Rani, Gunjan Dhiman and Deepak Kumar (Department of Geophysics Kurukshetra University Kurukshetra India) It has been suggested that the spectrum of high frequency strong ground motion from earthquakes is flat above the corner frequency to the maximum frequency (fmax) after which the spectrum decays fast (Hanks and McGuire, 1981). Anderson and Hough (1984) suggested a model for the shape of acceleration spectrum at high frequencies. This model is characterized by spectral decay parameter Kappa (κ). According to this model the fall off at high frequency is related to the attenuation along the wave path and near the surface. The spectral decay parameter has been used extensively to simulate the earthquake strong ground motions. It has been found in some studies that high frequency fall off have a source effect or it is combination of near surface attenuation and near surface effect. It has also been considered as related with recording site and earthquakes recorded. The spectral decay parameter has been estimated in the present study using the accelerograms of the earthquakes occurred in northwest and central Himalaya. These events include 1986 Dharmsala, 1991 Uttarkashi, 1999 Chamoli earthquakes and nine of its larger aftershocks. The 42 accelerograms recorded at different sites have been used in the present analysis. The values of κ found to be vary from 0.03s to 0.06s for the Dahrmsala region. We note a increase in the κ values with increase in distance. The attenuation of the region has been analyzed by estimating κ at different sites and source-station distances. The possible dependence of κ on site and earthquake size has also been investigated here. The estimated values of κ in this study is useful for the simulation of earthquake strong ground motions and therefore for the evaluation of seismic hazard in the region. References 1. Anderson, J.G. & Hough, S.E. (1984) A model for the shape of the Fourier amplitude spectrum of acceleration at high frequencies, Bull. Seism. Soc. Am., 74, January, Hanks, T.C. & McGuire, R.K. (1981) The character of high frequency strong ground motion, Bull. Seism. Soc. Am., 71, S6_P3 Estimation of Coda-Q using a Non-Linear (Gauss-Newton) regression Savita Singh ( Sumedha, Monika Wadhawan and Vandana (Department of Geophysics, Kurukshetra University Kurukshetra India) The study of attenuation of seismic waves is important for the estimation of earthquake source parameters, to predict earthquake strong ground motions and therefore useful in the evaluation of seismic hazard of a region. The attenuation of seismic wave is described by a parameter known as quality factor (Q). The Q can be estimated using body waves as well as coda-waves (Qc). The estimation of coda-q using local earthquakes has become a routine exercise. The simplest method to estimate coda-q is based on the single S to S back scattering model of Aki and Chouet (1975). The usual way to estimate coda- Q using this to linearize the equation of spectral amplitude of coda waves by taking logarithms of both sides and then to use the least square criterion. It has been suggested that the results of least square inversion on log transformed data may be biased. Therefore a nonlinear technique may be applied to estimate coda-q. A non-linear (Gauss-Newton) technique has been used in the present study to estimate the Qc from the coda envelope without linearizing the equation. In this technique the model parameters (including Qc) are estimated iteratively by expanding the relationship around the model parameters using a Taylor series expansion. The technique has been demonstrated on the waveforms of aftershocks of 1999 Chamoli earthquake. The events recorded at Ghat (GHA), Karanprayag (KPG), Pakhi (PAK), Gopeshwar (GPR) and Okhimath (OKI) have been analyzed. The Qc values have been estimated using both log-log as well as Gauss-Newton techniques. The initial values required in the Gauss-Newton technique have been obtained from log-log method. The preliminary results show that the values estimated by Gauss-Newton method are lower that those of log-log method. The results obtained using both methods have been compared and discussed. 51

82 S7: Real Time Seismology, Early Warning and Loss Assessment Conveners : Friedemann Wenzel and R.S. Dattatrayam THEME The aim of real-time seismology is to collect and analyze seismological data rapidly during a seismic crisis and utilize them for developing information on hazard, potential damage of large events, actual damage, and aftershock risk, with the aim of mitigating the earthquake impact on human society. Before a main shock the focus is on providing indications for an impending event by time-dependent assessment of hazard and risk. During a shock alert and shake maps of ground shaking allow rapid assessment of the expected area and scope of the earthquake; in many cases several seconds to a minute might be available for early warning sensu stricto with options to shut down critical facilities, secure industrial facilities, and issue alarms where appropriate. After the main shock rapid damage estimates based on seismological information and on a modeled structural environment can be delivered to the emergency institutions. Also, the risks associated with aftershocks can be assessed. Operational systems covering some of the aspects mentioned are meanwhile in place in Japan, Mexico, Taiwan, Europe and the U.S. The session will explore the state-of-the-art of this evolving technology and highlight application options in the Indian context. S7_Keynote Current trends in seismic instrumentation and earthquake monitoring in India R.S. Dattatrayam, A.K.Bhatnagar, G.Suresh, P.R.Baidya, J.L.Gautam, H.P.Shukla and Y.P.Singh (India Meteorological Department, Ministry of Earth Sciences, Lodi Road, New Delhi ) The great Sumatra earthquake of 26 th December, 2004, the second largest mega thrust event ever recorded on the planet Earth, reiterated the need for real time seismic monitoring for early warning of tsunamis. The Ministry of Earth Sciences (MoES) established a state-of-art Indian Tsunami Early Warning Center (ITEWC) at the Indian National Center for Ocean Information Services (INCOIS), Hyderabad on 15 th October, As part of this effort, a 17-station Real Time Seismic Monitoring Network (RTSMN) was set up by India Meteorological Department (IMD), to monitor and report, in least possible time, large magnitude undersea earthquakes capable of generating tsunamis from the two known sources, viz., the Makran coast in the north Arabian sea region and the Andaman- Nicobar-Sumatra island arc region. The ground motion data from the 17 field stations is transmitted simultaneously in real time through V-SAT communication facilities to the two CRSs (Central Recording Stations) located at IMD, New Delhi and INCOIS, Hyderabad for processing and interpretation. To provide better azimuthal coverage for locating earthquakes falling outside the coverage area of the network, about 80 seismic stations of IRIS (Incorporated Research Institutions for Seismology) Global Network have also been configured in the RTSMN system. The CRSs are equipped with state-of-art computing hardware, communication, data processing, visualization and dissemination facilities. The RTSMN system makes use of state-of-art auto-location software called, Response Hydra (V-1.47), developed by National Earthquake Information Centre (NEIC), United States Geological Survey (USGS), for real time location of earthquakes. It provides fast, reliable and accurate locations and magnitudes of world-wide, regional and local earthquakes. The final earthquake information / products are disseminated through various communication modes, such as, SMS, FAX, , IVRS and Website, to all the concerned user agencies in a fully automated mode. Based on the earthquake information provided by the RTSMN system and other ocean related observations / computations and analyses, INCOIS evaluates the tsunami-genic potential of the undersea earthquakes and issues necessary warnings / alerts as per January, 2011

83 Standard Operating Procedures (SOP). The Response Hydra also provides real time Centroid Moment Tensor (CMT) and Moment Tensor (MT) solutions for earthquakes of magnitude ranging between and respectively, which also helps in the assessment of tsunami-genic potential of undersea earthquakes. Various earthquake products generated by the RTSMN system in real time are depicted in Figure-1. the time taken for auto-location by RTSMN system typically varied between 3 minutes for an event in Nepal on 8 th December, 2008 (M:5.4 and Latitude: 29.7 degree North and Longitude: 81.8 degree East and located using 17-station data alone) to 13 minutes for an event in Java, Indonesia on 10 th December, 2008 (M:5.5 and Latitude: 7.1 degree South and Longitude:108.5 degree East). The paper presents the salient features of the RTSMN system, its Figure-1: Real time earthquake products generated by the RTSMN system. The RTSMN system is in successful operation for more than two years now and is providing real time products on earthquakes in the region, which are comparable to those generated by equivalent regional and global networks such as, USGS, GEOFON and EMSC. The auto-location capabilities of the RTSMN system have been compared with those of USGS and it is seen that the performance is found to be very satisfactory, particularly for large magnitude earthquakes occurring in the region. The difference in the magnitudes estimated by the RTSMN system and that of USGS are well within +0.2 units for majority of the events. Similarly, the epicentral locations and focal depths of majority of the events are broadly in good agreement (within km and km. respectively) with those of USGS. For earthquake events occurring well within the Indian landmass, the RTSMN system has provided better hypocentral estimates than other networks, as expected. In terms of response time, it is seen that January, 2011 efficacy and performance vis-à-vis the other global networks in operation for monitoring large magnitude earthquakes in the region. S7_I1 EDIM Earthquake Disaster Information System for the Marmara Region, Turkey Wenzel, F. 1 ; Erdik, M. 6 ; Köhler, N. 1 ; Zschau J. 2 ; Milkereit, C. 2 ; Picozzi, M. 2 ; Fischer, J. 3 ; Redlich, J. 3 ; Kühnlenz, F. 3 ; Lichtblau, B. 3, Eveslage, I. 3 ; Christ, I. 4 ; Lessing, R. 4 ; Kiehle, C. 5 ( 1 Geophysical Institute, Karlsruher Institute of Technology (KIT), 2 GeoForschungsZentrum (GFZ) Potsdam, 3 Computer Science Department, Humboldt University Berlin, 4 DELPHI IMM GmbH, Potsdam, 5 lat/lon GmbH, Bonn 6 KOERI, Bogazici University, Istanbul) 53

84 The main objectives of EDIM ( EDIM.php) are to enhance the Istanbul earthquake early warning (EEW) system with a number of scientific and technological developments that in the end provide a tool set for EEW with wide applicability. Innovations focus on three areas. (1) Analysis and options for improvement of the current system; (2) development of a new type of selforganising sensor system and its application to early warning; (3) development of a geoinformation infrastructure and geoinformation system tuned to early warning purposes. Development in the frame of the Istanbul system, set up and operated by KOERI, allows testing our novel methods and techniques in an operational system environment and working in a partnership with a long-standing traditon of success. EDIM is a consortium of Karlsruhe University (TH), GeoForschungsZentrum (GFZ) Potsdam, Humboldt University (HU) Berlin, lat/lon GmbH Bonn, DELPHI Informations Muster Management GmbH Potsdam, and Kandilli Observatory and Earthquake Research Institute (KOERI) of the Bogazici University in Istanbul. The integration of strong motion seismology, sensor system hard- and software development, and geoinformation real-time management tools prove a successful concept in making seismic early warning a novel technology with high potential for scientific and technological innovation, disaster mitigation, and many spin-offs for other fields. EDIM can serve as a model for further developments in the field of early warning on a global scale. S7_C1 Seismic loss Reduction/Estimation technique for use in Educational Spaces in Gujarat, India Chandra Bhakuni (Managing Director, QuakeSchool Consulting Pvt. Ltd., Ahmedabad, India) This paper proposes a risk assessment method for seismic protection of buildings by reducing the data input quantity of structural engineering aspects, and seeks improved quality of results with a containable error margin. We propose this as an improved method towards building an effective risk mitigation strategy, based on risk reduction principles which estimate maximum probable damages. The technique becomes highly useful for a large infrastructure set such as educational building infrastructure in a larger area. We make use of the globally available ground accelerations by Global Seismic Hazard Assessment Program (GSHAP), and have improved structural vulnerability curves after the 2001 Gujarat earthquake, and identify building typology; amongst other few parameters. This leads to identification of buildings which have high seismic exposure, thus seismic ranking, coming into use to classify facilities based on risk. As a fallout, the technique also helps to identify non-structural parameters, and other emergency planning aspects; which are useful in developing audit procedures and risk management information systems in case of other emergencies. If case of single building analysis the methodology provides conservative estimates due to absence of larger input data, more accurate soil related parameters, and problems such as liquefaction. S7_C2 The Seismic Alert System of Mexico (SASMEX) Espinosa-Aranda J. M.( Cuellar A., García A., Ibarrola G.and Islas R. (Centro de Instrumentación y Registro Símico, A. C.) The Mexico City and Oaxaca City authorities has convened the Seismic Alert System of Mexico City (SAS) and Seismic Alert System of Oaxaca City (SASO) integration development, both systems initially will conform the Seismic Alert System of Mexico (SASMEX), with a set of 48 sensing field stations, 17 radio relay stations. SAS started in 1991 and covers the Guerrero Gap and SASO started in 2003 and covers the seismic region of Oaxaca. They have emitted 78 early warnings of more than 2350 earthquakes detected by their sensing field stations. SAS information is used in Acapulco and Chilpancingo of Guerrero state by means of Alternate Emitters of Seismic Alert System (EASAS) to send the early warnings like in Mexico January, 2011

85 City. This work describes both systems, the current applications like schools, subway, public office buildings, emergency organizations, radio and TV commercial broadcast, and recently the NWR- SAME receivers, etc., finally the general aspects of SASMEX integration. S7_C3 Early Warning System for Transportation Lines E. Hohnecker 1, A. Buchmann 1, T. Titzschkau 2, F. Wenzel 2, D. Hilbring 3, G. Bonn 3, F. Quante 3 ( 1 Department of Railway Systems, Karlsruhe Institute of Technology, Otto-Ammann-Platz 9, Karlsruhe, Germany, 2 Geophysical Institute, Karlsruhe Institute of Technology, Hertzstr. 16, Karlsruhe, 3 Fraunhofer Institute of Optronics, System Technologies and Image Exploitation, Fraunhoferstr.1, Karlsruhe, Germany) Up to now, there are no earthquake early warning system applications that focus on the specific requirements of transportation lines, with the exception of a Japanese system for railways that has been developed since the 1980s. According to Nakamura the UrEDAS (Urgent Earthquake Detection and Alarm System) for railbound transportation is worldwide the only early warning system for transportation lines in operation. Recently, we have analyzed the potential of a new approach to earthquake early warning for railway systems, called EWS TRANSPORT [1]. The principle of functionality of EWS TRANSPORT is realized in an online demonstrator, publicly available under The demonstrator models and visualizes the entire early warning chain. This includes earthquake early detection and real-time risk reduction measures for railway transportation before and during the strong motion phase as well as fast infrastructure damage map generation after the event. Before and during the strong motion phase a risk reduction algorithm defines emergency measures such as stopping of a train or train speed reduction as a function of local peak ground acceleration (PGA), train velocity, and certain acceleration thresholds based on experience made in Japan. After the strong motion phase damage assessment is performed for various railway infrastructure elements. For example, for railway bridges five bridge damage classes (none, minor, moderate, major, complete) and the corresponding median PGA values are defined for various generic bridge construction types. Currently, these research results are represented in the demonstrator with geospatial and railway infrastructure data bases from the federal state of Baden-Württemberg in Germany as required data are available to us for this region. However, if corresponding data from high seismicity areas become available, the results can be extended to such cases. References [1] D. Hilbring et al., Natural Hazards, Springer, in press (2010) S7_C4 Seismo-Tectonic interpretations for the Delhi Region Based on the Data Recorded at Delhi Seismic Array Vivek Mahadev and Neelu Mathur (Delhi Seismic Unit, Seismology Division, BARC, New Delhi) This case study is based on data recorded at Delhi Seismic Array (DSA) of BARC at New Delhi which aims in identifying and characterising active faults to evaluate seismic hazards in generally moderateseismicity Delhi Region. Seismically active trijunction of MDSSF, SDR and Aravalli Delhi Fold Belt regions are generally characterised by low-hazard but highrisk, due to the concentration of human and material properties with high-vulnerability. Detecting tectonic deformations that may lead to destructive earthquakes in such areas requires innovative research strategies and continuous monitoring of slowly deforming faults due to man made changes and/ or natural tectonic movements. The paper highlights the simple use of available visual aids to understand the correlation between seismicity and Geo-tectonic features January,

86 S7_C5 Earthquake Vulnerability Assessment of Gujarat Port Sites Viz-a-viz Seismic Disturbances Terala Srikanth 1, Ajay Pratap Singh 2, Sumer Chopra 2, Ramancharla Pradeep kumar 1 and B.K.Rastogi 2 ( 1 Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad , India. 2 Institute of Seismological Research (ISR), Gandhinagar , Gujarat, India. Gujarat State of India is a principal maritime state endowed with strategic port locations. Kutch (Kachchh) region of the state was severely shaken by a powerful earthquake on 26 January This earthquake most seriously affected the Kandla port in addition to minor damages at other ports. About five of 10 jetties were damaged, reducing the berthing facility at the port. There were severe damages to the customs house, the administrative house, and cargo handling equipment. In this regard, there is a serious concern about the safety of port sites near Gujarat coast in view of seismic disturbances. Most of the port structures were constructed before the seismic codes were developed. In light of the tremendous business and secondary losses associated with prolonged interruption of port operations, it is necessary to check the vulnerability of coastal installation. For the purpose of study, four ports, viz., Kandla, Pipavav, Mundra and Dholera are selected. These ports consist of a wide range of structures and among which Jetty, conveyor belt, port building and buried pipelines that were selected for the study. At first, several earthquake scenarios will be developed and seismic hazard due to each will be assessed. PGA maps, site specific response spectra, liquefaction potential maps will be prepared for each earthquake scenario. Secondly, the performance of the structures will be evaluated by sophisticated nonlinear dynamic analysis. Since the structures are located on soil susceptible for liquefaction, oilstructure interaction effects will be considered in the analysis. S7_C6 Performance Analysis of Mundra Panipat Pipeline Crossing Kachhach Mainland Fault Vasudeo Govind Choudhary and Ramancharla Pradeep Kumar (Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad , India.) Gujarat has major pipeline network in the country, which is constantly spreading and will boost up after dreamed Iran-Pakistan-India pipeline. Pipeline networks provide energy for generating power, transportation, produce necessary goods and services to maintain a high quality of life in a modern society. Hence, pipelines are often referred to as lifelines. The wellbeing of community needs these lifeline systems to continue their function even under adverse situations. However, many pipelines in India run through high seismic areas and are exposed to considerable seismic risk. Bhuj earthquake of 26 Jan 2001 has already exposed several deficiencies in design and construction the pipelines. In this regard, there is a serious concern about the performance of pipeline during future earthquakes. In this study, we are considering MundraPanipat pipeline crossing Kachchh Mainland Fault. Since the considered pipeline falls in zones III to V as per seismic hazard map, design requirement needs to consider permanent ground displacement (PGD), uoyancy due to liquefaction, fault crossing and seismic wave propagation effects. At first we checked the safety of considered pipeline using the analytical method suggested by IITKGSDMA guidelines and later nonlinear numerical analysis was employed to study the capacity to pipeline for resisting the maximum displacement January, 2011

87 S7_C7 Rapid Visual Survey of Existing Buildings in Gandhidham and Adipur Cities, Kachchh, Gujarat Terala Srikanth 1, Ajay Pratap Singh 2, Santosh Kumar 2, Ramancharla Pradeep kumar 1 and B.K.Rastogi 2 ( 1 Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad , India. 2 Institute of Seismological Research (ISR), Gandhinagar , Gujarat, India) Bhuj earthquake of 26 January 2001 caused 14,000 casualties. Main reason for such huge casualties is low earthquake awareness and poor construction practices. Based on the technology advancement and knowledge gained after earthquake occurrences, the seismic code is usually revised. Last revision of IS 1893 (Criteria for earthquake resistant design of structures) was done in 2002 after a long gap of about 18 years. Some new clauses were included and some old provisions were updated. Assuming that concerned authorities will take enough steps for code compliance and the structures that are being constructed are earthquake resistant. In this light, what will happen to the safety of precode revision structures? These structures carry major percentage of vulnerable structure stock. Even if we have a very good disaster response system, it is impossible to reduce earthquake damage without considering the safety of precode revision structures. In this regard, a comprehensive study of seismic risk assessment of Gujarat is necessary. As a pilot study, government of Gujarat selected Gandhidham and Adipur cities in Kachchh district. Rapid Visual Screening (RVS) was conducted on buildings in Gandhidham and Adipur cities. Though, there are varied construction practices, about 26% of buildings were predominantly RCC type and 74% of masonry structure were found. RVS score of these structures reveal that in general buildings are of low quality and further evaluation and strengthening of buildings is recommended. The procedure adopted in this study is threetier method, i.e., Tier 1. Rapid Visual Screening, Tier 2. Preliminary assessment and Tier 3. Detailed assessment January,

88 S8: Earthquake Ground Motions and Damaging Earthquakes Conveners : Kojiro Irikura and Sumer Chopra THEME The high amplitude ground motions near large earthquakes cause severe damage to life and property. The high frequencies present in a near field record are due to the complexities on the fault surface and partly due to the scattering by inhomogeneities in the surrounding medium. Therefore the strong motion data are very useful in the study of details of the rupture process. The task is challenging for seismologists to study these near field records of damaging earthquakes which have occurred in the past and prepare models for predicting future large earthquakes in potential areas with reasonable accuracy. A number of techniques recently have been proposed to predict earthquake ground motions. The session aims at discussing latest techniques of predicting earthquake ground motions and lessons learnt from past damaging earthquakes. S8_I1 The great Sumatra earthquakes: Results from recent marine studies Satish C. Singh (Institut de Physique du Globe de Paris, France ( and University of Cambridge, UK) The great earthquake of 26 th December 2004 offshore Sumatra was the second largest earthquake to have been recorded by modern systems. It ruptured 1300 km of plate boundary over a 150 km-wide area from northern Sumatra all the way to the Andaman Islands. The tremor and the subsequent tsunami caused massive devastation and loss of life. Three months later, another 8.7 magnitude earthquake occurred on March , 300 km further south. On 12 September 2007, the third great earthquake (Mw=8.5) occurred 1300 km further south. There is a 600 km gap between the 2005 and 2007, which is likely to break in the coming years. During the 30 th September 2009 earthquake (Mw=7.8) only a small fraction of energy was released, which led to a death toll of over 2000, and a bigger earthquake is likely to occur in the near future. After the 2004 great earthquake, we have carried out five marine studies, two of which were funded by industry (Schlumberger and CGGVeritas, Singh et al., 2009). We have able to image the subducting plate from the seafloor 60 km depth. Here are some of the main results: 1. We find that downgoing oceanic crust is faulted down to 30 km depth, which suggests that the 2004 great earthquake might have ruptured a megathrust in the mantle (Singh et al., 2008). 2. The thrust in the mantle could be produced by the change in the dip of the downgoing plate, leading to underplating of the oceanic crust and uplifting the Islands. 3. We have imaged a backthrust at 180 km from the subduction front in the 2004 earthquake region, which might have ruptured during the great earthquake and enhanced the tsunami in Banda Aceh (Chauhan et al, 2009). 4. We have also imaged backthrusts in the seismic gap region. If this backthrust ruptures coseismically, it might lead to enhancement of tsunami and seismic risk to the SW of Sumatra (Singh et al., 2010). 5. We find that the reflectivity of the backthrust is brighter in the 2004 and 2007 great earthquake regions and weak in the locked zone, which could be due to the presence of fluid from the mantle along re-activated backthrusts. 6. We have imaged a subducted seamount at km depth and show that the presence of seamount weakens the couple between the downgoing plate and the overriding plate and could be responsible for the earthquake segmentation along the subduction zone. I will discuss the above points using deep seismic reflection, refraction, earthquake, GPS and seafloor bathymetry data January, 2011

89 Reference: Singh, S.C., Hananto, H., Chauhan, A.P., Permana, H., Denolle, M., Hendriyana, A., Natawidjaja, D. (2010a). Seismic evidence of active backthrusting at the NE Margin of Mentawai Islands, SW Sumatra, Geophys. J. Int. 180, Singh, S.C., Midenet, S., Djajadihardja, Y. (2009). Seismic survey of the locked and unlocked Sumatra subduction zone, EOS 90, Chauhan, A., Singh, S.C. et al. (2009). Seismic imaging of forearc backthrusts at northern Sumatra subduction zone, Geophys. J. Int. 179, Singh, S.C., Carton, H., Tapponnier, P. et al. (2008). Seismic evidence of broken crust in the 2004 Sumatra earthquake epicentral region, Nature Geosciences 1, S8_C1 Estimation of H/V ratio in different site in northern Algeria with aftershock sequences of Boumerdes earthquake M.Mobarki ( M.Hamdache and A.Talbi. (Seismological Dept.Survey. CRAAG. BP 63 Bouzareah Algiers-Algeria) The recent seismic activity in northern Algeria, especially during the last 50 years, is characterized by the occurrence of several damaging earthquakes. The EL Asnam region suffered the most destructive and damaging earthquake recorded in Northern Algeria, namely those of September 9, 1954 (M s 6.8) and October 10, 1980 (M w 7.3). The most significant and recent event was the May 21, 2003 (M w 6.9) Zemmouri earthquake, located at around 50 km Northeast of Algiers. It is well established that the seismicity in northern Algeria is the result of the compressional movement between African and Eurasian plates. This seismicity is mainly located in Tellian Atlas. In this context, the interest of the scientific community regarding seismology and seismotectonics has greatly increased in Algeria, especially in the fields related to the seismic risk assessment of urban seismic areas and its possible reduction. The main task of this study is related to the analysis of site effects observed during the seismic crisis generated by the Zemmouri January, 2011 earthquake of 21 May We used the recorded accelograms by temporary array of thirteen triaxial digital accelerographs (Kinemetrics and Reftek) deployed in the epicenter area to monitor aftershocks. About 1000 events triggered this array during the three-month deployment period. Based on site response analyses of S waves and coda waves of ground motion recordings, both types of waves show that the H/V ratios provide a good estimate at the resonant frequency. In this study, we conducted an analysis of the reliability and applicability of the H/V ratio, using the popular Nakumura technique to determine the resonance frequency (fo) of amplification (Ao), we chose a high-quality data set covering the 2003 Boumerdes earthquake sequences in order to identify site effect in different area. Key words: Nakumura, Amplification, resonance frequency, site effect. S8_C2 Ground motion parameters of Shillong plateau: One of the most seismically active zones of Northeastern India Saurabh Baruah 1, Santanu Baruah 1 Naba Kumar Gogoi 2 Olga Erteleva 3 Felix Aptikaev 3 and J R Kayal 4 ( 1 Geoscience Division, North-East Institute of Science and Technology (CSIR), Jorhat , Assam, India, 2 National Geophysical Research Institute, Hyderabad , India, 3 Institute of Physics of the Earth, Moscow , Russia, 4 School of Oceanographic Studies, Jadavpur University, Kolkata , India. Strong ground motion parameters for Shillong plateau of northeastern India are examined. Empirical relations are obtained for main parameters of ground motions as a function of earthquake magnitude, fault type, source depth, velocity characterization of medium and distance. Correlation between ground motion parameters and characteristics of seismogenic zones are established. A new attenuation relation for peak ground acceleration is developed, which predicts higher expected PGA in the region. Parameters of strong motions, particularly the predominant periods and duration of vibrations, depend on the morphology of the studied area. The 59

90 study measures low estimates of logarithmic width in Shillong plateau. The attenuation relation estimated for pulse width critically indicates increased pulse width dependence on the logarithmic distance which accounts for geometrical spreading and anelastic attenuation. The peculiarities of ground motion on the Shillong Plateau and its vicinity are considered. Obtained results allow to predict seismic treatment due to expected strong earthquakes and may be cosidered as a basis for the seismic hazard assessment in the region under investigation. S8_C3 Characterization of seismic regime in NW Himalaya: Persistent and high seismicity in the epicenter zone of great 1905 Kangra earthquake Naresh Kumar*, B. R. Arora, D. K. Yadav and V. M. Choubey (Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun India) We attempted to quantify the seismic regime of NW Himalaya (26ºN-34ºN and 74ºE-82ºE) through space time distribution of seismicity from historical time (1550) to recent time. Recent M7.6 Kashmir earthquake of 8 th October, 2005 and the great Kangra earthquake of 1905 have caused a heavy loss of life and property in this region. Although the available seismological data has limited historical records and magnitude range, the evidence of major (M>6) earthquakes during last five centuries, indicates that this region has been repeatedly fractured and affected by major events. Most of the events are confined to a narrow belt between surface trace of the Main Central Thrust (MCT) and Main Boundary Thrust (MBT). The regionalizations of seismic deformation divide whole seismic belt into sub-area with homogeneous seismic regimes. Space-time distribution of seismicity (mainly post 1965) reveals highly heterogeneous segmentation with well defined sections of high seismicity centered on Kangra- Chamba, Kinnaur, Garhwal and Dharchula regions. This picture become more apparent in the post 1999 period when the minimum detection threshold of earthquake further reduced to M=2.5 following addition of new local seismic stations. Kangra-Chamba region (epicenter zone of 1905 great Kangra earthquake) is by far the most seismically active area, with persistent shallow focused clustered seismicity in a very confined focal volume with majority of compressive regime. Persistent high seismic zone is evident by the clustering of epicenters and energy released irrespective of the duration and period of records examined. The recent seismic data through dense local seismic network indicate predominant compressive regime in the southern and central part, limited localised extensional regimes in the northern part and intermediate depth, and also strike-slip dominant deformation in the eastern part of 1905 Kangra earthquake. S8_C4 Strong Ground Motion Simulation of the 2001/ 01/26 Bhuj, India Earthquake Tao-Ming Chang (National Center for Earthquake Engineering Research, Taipei, Taiwan During the 2001/01/26 Bhuj earthquake sequence, global seismic network only record one main shock and one aftershock. Inside the earthquake affected zone, no modern digital strong motion records for the main shock has been recorded. Therefore synthetic acceleration seismograms are necessary for many other researches such as hazard analysis, earthquake loss estimations and earthquake engineering studies. In 2001/01/28 a Mw5.7 aftershock happen with very similar focal mechanism to main shock. Since the seismic moment energy ratio for main shock and after shock is 657. Therefore in this study we use empirical Green s function technique to calculate the source time function for several different stations. Then perform a search to find a rupture process for the Bhuj main shock. Also a second method used in this study to estimate main shock rupture process by using Genetic algorithm to match teleseismic P- wave waveforms. These two processes are compared. Finally, we use wavenumber integration method to calculate synthetic seismograms for different part on the rupture plane for different distances and assemble them as a complete synthetic acceleration seismograms to different locations. A seismic January, 2011

91 intensity map for Bhuj earthquake can be obtained. Many synthetic seismograms can be provided for other researches. S8_C5 Recipe for Predicting Strong Ground Motions for Inland Mega Fault Earthquakes Kojiro IRIKURA (Aichi Institute of Technology & Kyoto University, 1247 Yachigusa, Yakusa, Toyota, Aichi , Japan) Susumu KRAHASHI(Disaster Prevention Research Center, Aichi Institute of Technology) From recent developments of the waveform inversion of strong motion data used to estimate the rupture process, we found that strong ground motion is primarily related to the slip heterogeneity inside the source rather than average slip in the entire rupture area. Asperities are characterized as regions that have large slip relative to the average slip on the rupture area. There are two scaling relations, one between rupture areas and seismic moments, and the other between asperity areas inside the rupture area and seismic moment. We developed a recipe for predicting strong ground motions from specific faults based on those two scaling relations between fault parameters and seismic moments. Then, strong ground motions from specific faults are estimated using the characterized source model based on the recipe and numerical and empirical Green s functions. However, the data have been limited to intermediate-sized earthquakes less the Mw 7. Therefore, verification and applicability of the recipe also have been made using observed ground motions from recent disastrous inland-crustalearthquakes less than Mw7.In this study, we examined the scaling relations for mega-fault systems using 11 earthquakes (Mw ) of which source processes were analyzed by waveform inversion and of which surface information was investigated. We found that maximum displacement of surface rupture saturates at 10m when fault length(l) is beyond 100km, L>100km. Based on the above results, we develop three-stages scaling model between rupture area and seismic moment as the scaling relation for outer fault parameters. We also examined the scaling relations concerning asperity areas and stress drops, combined with the relations between acceleration source spectral-levels and seismic moments. We attempt to validate the characterized source model for simulating strong ground motions during the 2008 Wenchuan earthquake of Mw 7.9 as an example of the inland mega-fault earthquakes. S8_C6 Estimation of damage to various types of buildings in Gujarat from a future large earthquake Sumer Chopra ( Dinesh Kumar and B.K.Rastogi (Institute of Seismological Research, Gandhinagar ) The Gujarat state has witnessed the disaster during 2001 Bhuj earthquake. In order to prepare and prevent for such disasters from future large earthquakes in Gujarat, we have estimated the damage to various types of buildings. The peak ground accelerations at important towns of Gujarat from future large earthquakes are estimated by deterministic seismic hazard analysis taking into account the source, path and site effects specific for the site. A vulnerability function, developed by Arya (2000), has been used for the estimation of building loss. The building data of the cities/talukas has been taken from 2001 census of Gujarat for this purpose. According to this census the buildings in Gujarat are broadly classified into three types based on materials used in walls. The average loss ratio in percent has been calculated for various building classes using maximum intensity obtained in that region. Based on this, the number of buildings likely to be damaged in a taluka/city is estimated. A total of 3.7 lakh houses in Kachchh district are vulnerable to total damage in case of a large earthquake of M > 7.5 in Kachchh. In Saurashtra, most vulnerable talukas are Rajkot, Jamnagar, Surendranagar, Morbi, Junagadh and Dwarka where 3.2 lakh buildings are likely to be affected during a severe earthquake. The buildings in Radhanpur and Bharuch talukas in mainland are most vulnerable due to their proximity to active regions. In Ahmedabad, 25,000 five-storey and 1500 eleven-storey buildings are vulnerable to damage from a future large earthquake in Kachchh and are at highest risk if they have not been designed taking into account the earthquake forces January,

92 S8_C7 Strong motion simulation of Great earthquake in the central seismic gap region of Uttarakhand Himalaya Kapil Mohan (Institute of Seismological Research, Next to Petroleum university, Raisan, Gandhinagar,Gujarat (India) ;, A. Joshi (Department of Earth science, Indian Institute of Technology (IIT), Roorkee, India) Uttarakhand Himalaya in India lies in the central seismic gap region identified by Khattri and Tyagi (1983). Most of the area in Uttarakhand state has been placed under zone V and zone IV of the seismic hazard map published by Bureau of Indian standard, Govt. of India (BIS,2000). Some of the thrust/faults in the region manifest evidence of neotectonics and recurrent seismicity (Valdiya and Pant, 1986; Valdiya, 1999; Thakur; 2004; Paul et al., 2004). On the basis of strain accumulation, Bilham et al. (2001) suggested a magnitude M>8 earthquake in this region. In the present work a great earthquake along Main Central Thrust in the central seismic gap region has been modeled using semi empirical technique of Joshi and Mohan (2008). The shear wave quality factor used for modeling strong ground motions is computed using the database of strong motion earthquakes recorded by a local network in Kumaon Himalaya using the method of damped least square inversion. A total S phases of 27 strong motion records from six stations have been used for this inversion. An average relation in the form Q â (f) = 30f 1.45 has been obtained for Pithoragarh region of Kumaon Himalaya (Joshi et al., 2010). The strong motion parameters (Peak ground acceleration (PGA), Spectral acceleration and normalized spectral acceleration) are computed at five stations (Sobla, Didihat, Munsiari, Dharchula and Pithoragarh) in Uttarakhand Himalaya. The maximum PGA of 2g is calculated at Sobla station that is located in the down dip side of the rupture plane and minimum PGA (0.15g) at Pithrogarh station. The spectral acceleration is also computed on all five stations at T= 0.4s, T= 0.75s and T= 1.25s. The maximum spectral acceleration in all three periods is highest at Sobla station. In other four stations the spectral acceleration varies from 0.18g to 1.44g (at 0.4s), 0.11g to 0.85g (at 0.75s) and 0.06g to 0.48g (at 1.25s). The normalized spectral acceleration (Sa/g) is also calculated at all five stations. It varies from 0.62g to 2.01g (at 0.4s), 0.30g to 1.8g (at.75s) and 0.18 to 0.72(at 1.25s). This type of study is quite helpful for seismic resistant designs in earthquake prone areas and to assess the damage potential of various types of buildings due to an earthquake in the vicinity. Keywords: Seismic gap, great earthquake, peak ground acceleration, peak spectral acceleration, normalized spectra. S8_P1 Attenuation relations for the Kumaon and Garhwal Himalaya, Uttarakhand, India Joshi and A. Kumar(Department of Earth Science, Indian Institute of Technology Roorkee, Roorkee, India.), A. Sinvhal (Department of Earthquake Engineering, Indian Institute of Technology Roorkee, Roorkee, India.) Uttarakhand Himalaya is among most seismically active regimes of the world. The whole region is divided into two major parts i.e. Garhwal Himalaya and Kumaon Himalaya. For Himalayan region very few attenuation relations have been developed which can be applied to the different parts of Himalaya separately. In Himalayan region limited availability of sufficient strong motion dataset pose difficulty for obtaining attenuation relations which are applicable for different region within entire Himalaya. Using limited data sets two attenuation relations have been prepared for Garhwal Himalaya and Kumaon Himalaya, respectively. Strong motion data from a network strong ground motion recorders operating in the Kumaon Himalaya between 2006 to 2008 has been used as input to develop regression relation. For developing regression relation for Kumaon Himalaya one hundred fifty one strong motion records have been as an input in the regression study. The data set cover the magnitude and hypocentral ranges between 3.5 d M w d 5.3 and 10 d R d 100 km, respectively. Peak ground acceleration from strong motion records from a strong motion array deployed in Garhwal Himalaya has been used for prepared regression relation for Garhwal Himalaya. Twenty nine strong motion records from a network January, 2011

93 operating in Garhwal region has been used as input to regression study. Strong motion data from Garhwal Himalaya have been downloaded from website developed and maintained by the Department Earthquake Engineering Indian Institute of Technology Roorkee. The data set cover the magnitude and hypocentral distance ranges between 3.7 d M w d 5.3 and 20 d R d 213 km, respectively. Following two regression relations has been obtained for Garhwal and Kumaon Himalaya, respectively in this work: For Kumaon Himalaya: Log (PGA) = M w R -.45 log (R+15) For Garhwal Himalaya: Log (PGA) = M w R -.38 log (R+15) Where peak ground acceleration (PGA) is in gal, M w is moment magnitude and R is hypocentral distance in km, respectively. The fit of regression with observed data confirm the utility of developed regression. S8_P2 Prediction of Strong ground motion in the Coastal and Economically Important Regions of Gujarat using Deterministic Seismic Hazard Model Kapil Mohan (Institute of Seismological Research, Gandhinagar, Gujarat (India) The expected peak ground acceleration at fifteen stations in the coastal region of Gujarat are estimated using semi empirical approach (Joshi et al., 2001; Joshi and Midorikawa, 2004) at B/C boundary NEHRP level. The semi empirical technique is similar to empirical green function (EGF) technique of Irikura (1986) however the requirement of aftershocks is replaced by simulated time series having envelope of accelerograms in time domain and spectral contents of high frequency accelerograms in the frequency domain. This method follows omega square decay at high frequencies, directivity effects and other strong motion properties. To estimate the maximum possible damage, an earthquake of magnitude M w 7.6 along the central part of Kachchh Mainland Fault (KMF) (Scenario I) and magnitude M w 7.5 along eastern part of Katrol Hill Fault (KHF) (scenario II) is considered in this study. The attenuation characteristic of Eastern North America (ENA) matches with the Kachchh region of Gujarat (Cramer and Kumar, 2003). The attenuation relationships of Toro et al., 1997, Atkinson and Boore, 1995 (after applying corrections for B/C site suggested by Frankel et al., 1996), Frankel et al., 1996 and Somerville et al., 2001 of ENA and Iyengar and Raghukanth (2004) and Mandal et al., 2009 of western central region (Peninsular India) and Kachchh region of Gujarat, respectively at B/C site are tested with the Structural Response Recorder (SRR) data and strong motion data of 2001, Bhuj earthquake. The 2001, Bhuj earthquake data correlated best with Atkinson and Boore (1995). The root mean square error (RMSE) of Toro et al., 1997 (after applying correction for B/C site) and 2001, Bhuj earthquake recorded data was found the least. The average of Atkinson and Boore (1995), Toro et al., 1997 of ENA and Mandal et al., 2009 of Kachchh has been considered in the present study to estimate the expected peak ground acceleration. The maximum peak ground acceleration (PGA) of 290 cm/sec 2 is calculated at Kandla due to Scenario I whereas the maximum PGA of 264cm/ sec 2 is calculated at Mandvi due to scenario II. The maximum PGA of 22 cm/sec 2 and 12 cm/semc 2 is calculated at commercially important Dholera and Bharuch special economic zone (SEZ), respectively due to Scenario I. The maximum PGA difference (156 cm/sec 2 ) due to both scenarios is found at Mandvi whereas the minimum PGA difference (0.6 cm/sec 2 ) is found at Talala station. Keywords: strong motion simulation, semi empirical technique, NEHRP B/C boundary, peak ground acceleration January,

94 S9: Seismic Hazard Assessment/Microzonation Conveners : A. Peresan, Fumio Kaneko, T.G. Sitharam and Imtiyaz Parvez THEME Development of effective mitigation strategies requires sound seismic microzonation and seismic hazard information. The purpose of seismic hazard assessment (SHA) is to provide a scientifically consistent estimate of seismic hazard for engineering design and other considerations. The time is ripe to move beyond traditional Probabilistic Seismic Hazard Assessment, because it is not based on earthquake sciences (i.e., invalid earthquake source model, misuse of statistics, and invalid mathematics). PSHA practice has become the old good paradigms of widespread ignorance and intolerance to any revision. Although there are many approaches available for SHA, this Session advocates the advanced methods for seismic hazard assessment and seismic microzonation that utilize up to date earthquake science and basic scientific principles to derive the seismic hazard in terms of a ground motion or related quantity and its occurrence frequency at a site, as well as the associated uncertainty. The Session is addressed to seismologists, engineers and stake-holders, and aims to contribute bridging modern interdisciplinary research and end-users, who have to cope with the problems of the earthquake risk management and natural disasters preparedness. S9_I1 Seismic Hazard Assessment for Gandhidham; Kutch; Gujarat Fumio Kaneko 1 ( Michio Morino 1 ( Shukyo Segawa 1 ( Jun Matsuo 1 ( Koichi Hasegawa 1 ( Javed Malik 2 ( and Sushil Gupta 3 ( address: ( 1 OYO International Corporation, 2 Indian Institute of Technology Kanpur, 3 RMSI Private Limited) Comprehensive seismic hazard assessment was conducted for Gandhidham area including Anjar city. Allah Bund Fault (ABF), Island Belt Fault (IBF), Kutch Mainland Fault (KMF) and Bhuj - Katrol Hill Fault (BF and KHF) are selected as the scenario earthquakes. The trench survey was conducted and revealed that KMF, KHF and BF are indeed active. 80 drilling and 16 PS loggings are conducted at the site. It was confirmed that Vs and N-value has good relation in this area as in other region. The surface ground of the study area was modeled for every 250m sq. grids up to engineering seismic bedrock. The subsurface amplification is evaluated by empirical amplification factor from AVS30 and site response analysis, and they show good relation. In conducting this study, following points are found to be improved for future hazard assessment study in India; 1) Shallow ground condition should be studied more. Actual S-wave velocity should be surveyed. 2) Seismic source research work including active fault trench study and paleo-seismic study are necessary. 3) All the data relating hazard assessment should be open to the researchers and engineers. S9_I2 Seismic Hazard Assessment based on Unified Scaling Law for Earthquakes Anastasia K. Nekrasova(International Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, 84/32 Profsoyuznaya Street, Moscow , Russian Federation); Vladimir G. Kossobokov(International Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, 84/32 Profsoyuznaya Street, Moscow , Russian Federation; Institut de Physique du Globe de Paris, Paris, France January, 2011

95 There is growing stream of the best documented instrumental observations that evidently contradict to generally accepted models of seismic hazard assessment. Many of the fatal assumptions attributed to seismic activity are misleading to unacceptable surprises like the 2001 Bhuj and 2008 Wenchuan great earthquakes and the most recent 2010 Haiti major earthquake disaster. Therefore, the model assumptions require a prompt serious revision. We suggest making use of the fact that earthquake locations have heterogeneous, possibly, fractal distribution in space (at scales from hundreds km to a few km or less), which implies systematic underestimation by traditional methodologies of seismic hazard for cities and urban agglomerations. The confirmed patterns of distributed seismic activity follow the Unified Scaling Law that generalizes Gutenberg-Richter recurrence relation as follows: Log N(M,L) = A - B (M - 5) + C Log L, where N(M,L) is the expected annual number of earthquakes of magnitude M within an epicenter prone locus of liner size L. For a wide range of control parameter A from under -1.0 to above 0.5 (which value determines the average rate of magnitude 5 earthquakes and, accordingly, differs by a factor of 30 or more), the balance between magnitude ranges, B, resides mainly from 0.6 to 1.1, while the fractal dimension of the local epicenter prone setting, C, changes from under 1 to 1.4 and larger. The underestimation of earthquake recurrence rate on transition from the territory of linear size L to the territory of linear size l equals (l/l) C - 2 when scaled down by traditional proportion to the area of interest. Stabilized version of a robust box-counting algorithm SCE (Scaling Coefficients Estimation) was applied to map the reliable values of A, B, and C worldwide. These basic characteristics of earthquake distribution the recurrence rates of moderate, strong, major, and great maps in terms of the maximum of expected intensity in 30, 50 and 100 years at the 10 % level of probability of exceedance. The results are compared to traditionally scaled estimates based on the observed recurrence rates in the extended neighborhoods of a city, as well as to traditional seismic hazard maps (GSHAP). The general level of underestimation of the rates is too large for being ignored in seismic risk and earthquake loss January, 2011 evaluations necessary for a knowledgeable disaster prevention and mitigation. Earthquakes are estimated in seismically active regions and, in particular, for cities and urban agglomerations, then used to provide a seismic hazard. S9_I3 Neo-Deterministic Seismic Hazard Techniques Contributions to the Alternative Representation of the Seismic Loading for Bulgaria. Kouteva M. 1, Paskaleva I. 1, Vaccari F. 2,3, Romanelli F. 2,3, Panza G.F. 2,3 ( 1 NIGGG-BAS, Sofia, Bulgaria, bg, 2 DiGeo-UTS, Trieste, Italy; 3 SAND-ESP, ICTP, Trieste, Italy) The new legislation about the earthquake engineering design and practice in Europe, Eurocode 8 (EC8), deals with the necessity of using alternative representation of the seismic input, e.g. accelerograms, for the non linear structural analyses of complex, irregular and/or important structures in seismic regions. Generally there are two approaches for the representation of the seismic input: (1) real recorded acceletrograms or (2) theoretically computed seismic signals. The use of real acceleration records requires comprehensive representative database of reliable data varying in epicentral distance, local site conditions and seismic source characteristics. Despite of the growing strong motion registration networks in Europe, the existing database is still not complete with regard to this variety and the lack of completeness will last for many years if not centuries. Therefore it is necessary to look for reliable methods, based on physical and mathematical models, used for seismic input definition via seismic waves propagation modelling. During the last decade, due to the lack of representative instrumental data in Bulgaria, our attention has been concentrated on exploring for physically and scenario based methods for SHA, going beyond the classical PSHA shortcomings, well documented by Kobe ( ), Gujarat ( ), Boumerdes ( ) Bam ( ), E-Sichuan ( ) and Haiti ( ) events, and its deficiency to supply realistic accelerograms as alternative seismic input 65

96 representations. Thus the neo-deterministic method (NDSHA) developed at the Department of Geosciences, University of Trieste, has been used for seismic hazard assessment at different scales in Bulgaria regional, national and urban. The major problem has been to couple the effect of both, shallow local and intermediate-depth Vrancea, seismic effects on the Bulgarian territory for design purposes. The large-scale application at regional and national level made it possible to shape a proposal for a zone within NE Bulgaria, in which the decisive Vrancea contribution requires to perform engineering structural analyses using two elastic spectral shapes, local and Vrancea ones. S9_I4 Neo-Deterministic Seismic Hazard and Pattern Recognition Techniques: Time-Dependent Scenarios for North-Eastern Italy. A. Peresan 1, 2, E. Zuccolo 3, F. Vaccari 1, 2, A. Gorshkov 2, 4 and G. F. Panza 1, 2 ( 1 Department of Earth Sciences, University of Trieste, via E. Weiss 1, Trieste, Italy. 2 The Abdus Salam International Centre for Theoretical Physics, ICTP, Trieste, Miramare, Italy., 3 EUCENTRE - European Centre for Training and Research in Earthquake Engineering, Via Ferrata, Pavia Italy., 4 International Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, Warshavskoe sh.79, kor.2, Moscow. An integrated neo-deterministic approach to seismic hazard assessment has been developed that combines different pattern recognition techniques, designed for the space time identification of impending strong earthquakes, with algorithms for the realistic modeling of seismic ground motion. The integrated approach allows for a time-dependent definition of the seismic input, through the routine updating of earthquake predictions and by means of full waveform modeling. A set of neo-deterministic scenarios is defined at regional and local scales, thus providing a prioritization tool for timely preparedness and mitigation actions. Constraints about the space and time of occurrence of the impending strong earthquakes are provided by three formally defined and globally tested algorithms, developed according to a pattern recognition scheme. Two algorithms, namely CN and M8, are routinely used for intermediate-term middle-range earthquake predictions, while the third algorithm does not belong to the family of earthquake prediction algorithms since it allows for the identification of the areas prone to large events. These independent procedures have been combined to constrain the alarmed area. Italy is the only region where the two different prediction algorithms, CN and M8S (i.e. a spatially stabilized variant of M8), are applied simultaneously and a realtime test of predictions, for earthquakes with magnitude larger than a given threshold (namely 5.4 and 5.6 for CN algorithm, and 5.5 for M8S algorithm) has been ongoing since Neodeterministic scenarios are provided, at regional and local scale and for the cities of Trieste and Nimis (Friuli Venezia Giulia region), where the knowledge of the local geological conditions permitted a detailed evaluation of the expected ground motion. S9_I5 Ground Motion at bedrock level in Delhi City from different earthquake scenarios\ Imtiyaz A Parvez 1, Fabio Romanelli 2 and Giuliano F Panza 2,3 ( 1 CSIR Centre for Mathematical Modelling and Computer Simulation (C-MMACS), NAL Belur Campus, Bangalore, India, 2 Department of Earth Sciences, University of Trieste, Trieste, Italy. 3 The Abdus Salam International Centre for Theoretical Physics, Trieste, Italy) Delhi, the capital of India, is prone to severe seismic hazards, not only from local events but also from Himalayan earthquakes at distances of km. Standard techniques are not sufficiently reliable to completely characterize the seismic hazards in this case due to the difficulty of predicting the occurrence of earthquakes (frequency magnitude relations) and of properly treating the propagation of their effects (attenuation laws), especially their long-period components. In order to give a sound description of the seismic ground motion due to an earthquake in such a given range of distances (and magnitudes), we use modeling techniques developed from physics January, 2011

97 of the seismic source generation and propagation processes. Such models take into account the directivity effect of rupture propagation and the attenuation of (long-period) ground motions. The generated ground motion scenarios permit us to build a very important knowledge base to be fruitfully used by civil engineers, since long period ground motions, especially if amplified by deep sedimentary basins, can represent a severe threat for large scale structures (e.g. lifelines and bridges) and tall buildings, which are widespread in fast-growing megacities. In this study, we simulate the ground motion, at bedrock level, in Delhi city, for two earthquake scenarios corresponding to a source of Mw = 8.0 located in the central seismic gap of Himalayas, at an epicentral distance of about 300 km and a regional earthquake scenario at a distance of 175 km from Delhi. By means of several parametric studies, we simulate the time histories using Size Scaled Point Source, Space and Time Scaled Point Source and Extended Source models. Together with the complete time histories (displacements, velocities and accelerations, from which the peak amplitudes have been extracted), we have also used the displacement response spectrum to characterize the seismic input at Delhi. Not only is the displacement response spectrum of great significance to modern displacement-based design engineering approaches, but it is probably the best parameter by which to characterize the destructiveness potential of earthquakes located at such great distances from the target sites (of the order of 300 km), since the energy of the seismic input is mainly concentrated at long periods (in general, greater than 1 s) and it cannot be determined by straight forward integration of velocity or acceleration response spectra. S9_I6 Robabilistic Seismic Hazard Macrozonation of India T.G. Sitharam ( Sreevalsa Kolathayar and K.S. Vipin (Department of Civil Engineering, Indian Institute of Science, Bangalore ) In view of the major advancement made in understanding the seismicity and seismotectonics of January, 2011 India during the last two decades, an updated probabilistic seismic hazard map of India covering 6 38N and E was prepared and presented in this paper. The earthquake catalogue was prepared by compiling the data from various national and international agencies. Homogenization of different magnitude scales to Moment magnitude was done and the catalog was declustered to remove the dependent events. A total of earthquakes of moment magnitude 4 and above were obtained from the study area after declustering, and were considered for further analysis. The sesismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones in the study area (SEISAT, 2000) which are associated with earthquakes of magnitude 4 and above. In probabilistic seismic hazard analysis (PSHA), the evaluation of PGA was done by considering the uncertainties involved in the earthquake occurrence process. The uncertainties in earthquake recurrence rate, hypocentral location and attenuation characteristics were considered in this study. For assessing the seismic hazard, the study area was divided into small grids of size , and the hazard parameters were calculated at the centre of each of these grid cells by considering all the seismic sources within a radius of 300 km. A logic tree approach, using two types of sources and different attenuation relations, was adopted for the evaluation of PGA values. The contour maps showing spatial variation of PGA value at rock level are presented in the paper. Keywords: Probabilistic Seismic Hazard Assessment, Attenuation relations, Peak Ground Acceleration S9-I7 Study of the Local Site Effects on Seismic Hazard Using Deterministic and Probabilistic Approaches: A Case Study of Karnataka State By T.G. Sitharam ( Sreevalsa Kolathayar and K.S. Vipin (Department of Civil Engineering, Indian Institute of Science, Bangalore ) Earthquakes hazards are one of the worst natural disasters, causing huge loss to human life and 67

98 manmade structures. It is impossible to prevent the earthquake from occurring so for mitigating its effect, a proper hazard study is required. Major seismic hazards causing extensive damages are ground shaking and liquefaction. These hazards depend upon the geotechnical properties of the soil overlying the bedrock as the characteristics of ground motion like amplitude, frequency and duration changes when the seismic waves travel from bed rock to ground surface and this phenomenon is termed as local site effect. The study of this variation is very important for shallow founded structures, geotechnical structures like retaining walls and dams, floating piles and underground structures as these are very vulnerable to above mentioned hazards. In this paper, the peak ground acceleration (PGA) at the ground surface was evaluated for the state of Karnataka. Karnataka is a state in the Peninsular India, tectonically forming the intraplate region of Indian plate. Major earthquakes like Bellary (M w 5.7 in 1843), Coimbatore (6.3 Mw in 1900), Koyna (M w 6.1 in 1967), Hassan (M w 5.6 in 1970) and Latur (M w 6.1 in 1993) showed that the region has reasonably high seismicity compared to other shield regions and hence the hazard assessment for the state is very necessary. In order to estimate PGA at ground surface, the hazard at the bedrock level was estimated first by deterministic and probabilistic approaches incorporating logic tree methodology considering events and earthquake sources within 300km from the boundary Karnataka. The state of Karnataka was divided into a grid size of 0.05 x 0.05 o and a MATLAB program was employed for both deterministic and probabilistic analysis using three attenuation relations proposed by Raghukanth and Iyengar (2007), Atkinson and Boore (2006) and Toro, (1997). By assuming the soil above bed rock of the whole region belonging to site classes A to D, as per NEHRP (National Earthquake Hazard Research Programme) and IBC (International Building Code) recommendation, the ground motion at surface level for each site class is obtained based on nonlinear site amplification technique proposed by Raghu Kanth and Iyengar (2007) for Peninsular India. Spatial variation of PGA values at ground level for site classes A to D is presented. Response spectra at rock level and at ground level for important cities like Gulbarga, Belgaum, Hubli, Bellary, Bangalore, Mangalore, Mysore and nuclear site at Kaiga in Karnataka were evaluated and the results are presented in this paper. S9_C1 Seismic hazard deaggregation in terms of magnitude, distance and azimuth at main cities of northern Algeria. M. Hamdache 1 ( J.A. Peláez 2 ( A. Talbi1, M. Mobarki 1 and C. López Casado 3 ( ) ( 1 Departement Études et Surveillance Sismique, CRAAG, Algiers, Algeria., 2 Department of Physics, University of Jaén,Spain, 3 Department of Theoretical Physics, Univ. of Granada, Granada, Spain, The recent seismic activity in northern Algeria, especially in the last 50 years, is characterized by the occurrence of several damaging earthquakes. The El Asnam region suffered the most destructive and damaging earthquakes recorded in northern Algeria, namely those of September 9, 1954 (MS 6.8) and October 10, 1980 (Mw 7.3). The most significant and recent event is the May 21, 2003 (Mw 6.9) Zemmouri earthquake, located at around 50 km northeast of Algiers. In this context, the interest of the scientific community regarding seismology and seismotectonics has greatly increased in Algeria, especially in the fields related to the seismic risk assessment of urban seismic areas and its possible reduction. We focus on the probabilistic seismic hazard in terms of PGA with 10% probability of exceedance in 50 years, which generally forms the basis for the seismic design provision of National Building Code. In this study, we disaggregate the probabilistic seismic hazard results in terms of magnitude, distance and azimuth, at several cities in Northern Algeria, to help understand the relative contributions of the different seismic focuses. These results are used to derive at each studied site a probabilistic seismic hazard curve by combining the contribution of the different seismic sources or scenarios. Also, based on these results, January, 2011

99 we compute the so-called control earthquake, that is, the most contributing earthquake to seismic hazard in a certain location from a probabilistic point of view. The calculation is performed for all main cities in northern Algeria, corresponding to the so-called 2D hazard disaggregation technique, which allows us to derive the mean and modal scenario at each site. Afterward, the mean and modal scenarios are used to simulate design accelerograms at each place for rock soil type. Keywords: Probabilistic seismic hazard, deaggregation, scenarios, control earthquake, stochastic simulation of accelograms, Algeria. 2C_9S Determination Site Effect of Zarqa City-Jordan Based on Microtremors Field Measurements: A microzonation Study By Waleed Eid Olimat (Natural Resources Authority (NRA), Jordan Seismological Observatory (JSO) 11118, P.O.Box # 7, Amman Jordan, Zarqa governorate is one of the important governorates in Jordan. It is the second populated after the capital Amman, the location of Zarqa gives the city a great importance because it lies on the main high ways leading to Syria, Iraq and Saudi Arabia, most of Jordan s industries, power plants and strategic projects are located in Zarqa, which gives this city a special importance. The Nakamura s technique is applied in this study for both areas; Zarqa city and Hashemite University Campus in order to determine the resonance frequencies and amplification factors for each site then draw there maps which will be of a great use in the field of civil and structural engineering by enriching the building codes. The results of our study show that; values of resonance frequency F are not affected by the time of recording. While values of amplification factor A can vary accordingly. Results also show that the amplification factor A varies from 0.8 to 8.55 in Zarqa city and the resonance frequency (F) also varies between 0.37 Hz and 2.98 Hz in Zarqa city, that means some constructions in the study area, in case of a major earthquake, may experience minor damages respectively. S9_C3 Probabilistic Seismic Hazard Analysis for Mitigating Societal Risk from Earthquakes Dr. Praveen K. Malhotra (Strong Motions Inc., Sharon, MA, USA, Praveen. P.E. (Strong Motions Inc., Sharon, MA, USA) A new method of computing the probabilistic seismic hazard analysis (PSHA) will be discussed. The current method does not capture the aggregate (or societal) aspect of seismic hazard; therefore it is not suitable for assessing and mitigating the societal risk from earthquakes. Earthquakes affect many people at the same time. They pose risk to individuals as well as to the society. The design ground motions in the current loading standards (such as IS and ASCE ) are based on site-specific probabilistic seismic hazard analysis (SS-PSHA). The site-specific hazard is defined by the probabilities of exceeding different levels of ground shaking at specific locations. The site-specific hazard does not say how many other locations will also experience the same or higher levels of ground shaking during the same earthquake. This is a significant shortcoming of the SS-PSHA, because the exceedance of design ground motion for 10,000 buildings has a very different effect on the society than the exceedance of design ground motion for a single building. A new definition of probabilistic hazard was proposed to capture the aggregate (societal) aspect of earthquakes (Malhotra 2007, 2009). The aggregate seismic hazard is defined by the probabilities of exceeding different levels of ground shaking simultaneously (during the same earthquake) at many locations occupied by more than a certain number of people. For example, what is the annual probability of exceeding 0.1 g acceleration at a location along with many other locations occupied by > 1 million people? The importance of aggregate probabilistic seismic hazard analysis (A-PSHA) will be highlighted by January,

100 identifying the limitations of SS-PSHA. Some preliminary results of aggregate hazard will be presented. Finally, a new method of establishing design ground motions for mitigating both individual and societal risks from earthquakes will be presented. S9_C4 Influence of Source and Epicentral Distance on Local Seismic Response in Kolkata city, India. William K. Mohanty 1 ( Akhilesh K. Verma 1, Franco Vaccari 2, 3, Giuliano F. Panza 2, 3 ( 1 Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur , India., 2 Department of Geosciences, University of Trieste, Italy., 3 The Abdus Salam International Centre for Theoretical Physics, Earth System Physics Section/Sand Group, Trieste, Italy.) Kolkata, the capital of West Bengal state is one of the oldest industrial cities in India. It is situated over the thick alluvium of the Bengal Basin, where it lies at the boundary of the zone III and zone IV of the seismic zonation map of India. The rapid increase in population density and industrial developments across the city has increased the seismic risk and therefore it is important to access the seismic hazard of the city for civil engineers and city planner for any future civil constructions. The influence of source and epicentral distance on the local seismic response in the Kolkata city is investigated computing the seismic ground motion along 2-D geological cross-sections in the Kolkata city for the earthquake occurred on 12 th June, 1897, (M w = 8.1; focal mechanism: dip = 57, strike = 110 and rake = 76 ; focal depth = 9 km) in Shillong plateau. To estimate ground motion parameters, the hybrid technique is used, which is the combination of modal summation and finite difference method and it allows the estimation of site specific ground motion for various events located at different distances from Kolkata city taking into account simultaneously the position and geometry of the seismic source, the mechanical properties of the propagation medium and the geotechnical properties of the site. The epicenter of the Shillong earthquake is about 470 km away from Kolkata. The estimated peak ground acceleration (PGA) varies in the range of g and this range corresponds to the intensity of IX to X on Mercalli- Cancani-Sieberg (MCS) scale and VIII on Modified Mercalli (MM) scale. The maximum amplification in terms of RSR varies from 10 to 12 in the frequency range Hz. These amplifications occur in correspondence of low velocity, shallow lose soil deposit. The comparison of these results with earlier ones obtained considering the Calcutta earthquake occurred on 15 th April, 1964 (M w = 6.5; focal mechanism: dip =32, strike = 232 and rake = 56 ; focal depth = 36 km) show that the source parameters (magnitude and focal mechanism) and epicentral distance play an important role on site response. The obtained results match with observed reported intensities in Kolkata region. Keywords: Kolkata city, Eocene Hinge Zone (EHZ), A MAX, response spectral ratio (RSR), peak ground acceleration (PGA), seismic sources, site response, hybrid technique. S9_C5 Neo-Deterministic and Probabilistic Seismic Hazard Assessments: a Comparison over the Italian Territory E. Zuccolo 1, F. Vaccari 2,3, A. Peresan 2, 3 ( and G. F. Panza 2,3 ( 1 EUCENTRE - European Centre for Training and Research in Earthquake Engineering, Via Ferrata, Pavia Italy., 2 Department of Earth Sciences, University of Trieste, via E. Weiss 1, Trieste, Italy., 3 The Abdus Salam International Centre for Theoretical Physics, ICTP, Trieste, Miramare, Italy. Recent strong earthquakes that have occurred in areas where neo-deterministic (NDSHA) maps were available, successfully confirmed the neodeterministically predicted ground shaking (e.g., the Boumerdes and Gujarat events), while the probabilistic estimates turned out to be severely underestimated. Estimates of seismic hazard obtained using NDSHA and the probabilistic approach (PSHA) are compared for the Italian territory. This comparison is, in fact, possible only in Italy thanks to January, 2011

101 the unique length of its earthquake catalogue. The NDSHA provides values larger than those given by the PSHA in areas where large earthquakes are observed and in areas identified as prone to large earthquakes, but lower values in low-seismicity areas. These differences suggest the adoption of the flexible, robust and physically sound NDSHA approach to overcome the proven shortcomings of PSHA, thus allowing for a reliable seismic hazard estimation, especially for those areas characterized by a prolonged quiescence, i.e. in tectonically active sites where events of only moderate size have occurred in historical times. S9_C6 Evaluation of site classification for soils in Lucknow urban centre And Correlation between SPT-N value and V s Abhishek Kumar, P. Anbazhagan ( Sitharam T G (Department of Civil Engineering, Indian Institute of Science, Bangalore, Karnataka , India) Evidences from past earthquakes clearly shows that the damages due to an earthquake and its severity are controlled mainly by three important factors i.e., earthquake source and path characteristics, local geological and geotechnical characteristics, structural design and construction features of structures. Generally, the soil layers over the firm bedrock may attenuate or amplify the bed rock earthquake motion depending upon geotechnical characteristics, their depth and arrangement of soil layers. Usually the younger softer soils amplify ground motion relative to older, more competent soils or bedrock. Local amplification of the ground is often controlled by the soft surface layer, which leads to the trapping of the seismic energy, due to the impedance contrast between the soft surface soils and the underlying bedrock. Many researchers have proved that site conditions play an important role in damage distribution as well as in the recorded strong motion records (Ishihara, 1997; Aki, 1998; Tertulliani, 2000; Hartzell et al., 2001, Ozel et al., 2002). It has been evident from the past earthquake events all over the world that the amplification of ground motion is highly dependent on the local geological, topography and January, 2011 geotechnical conditions. The determination of geotechnical site conditions requires identification of the soil stratification and properties of soil layers based on various in-situ tests and laboratory tests on soil and rock samples. The extent of area to be investigated for seismic microzonation generally spans over several kilometers unlike routine geotechnical site investigations and thus, geophysical tests are more reliable tools for understanding subsurface. They are based on the propagation of body waves and surface waves, which are associated to very small strain (< 0.001%). The geophysical tests are more advanced now a days, and these methods can be used more efficiently with less time to explore deeper depth and also larger aerial extent, which is quite needed mainly in deeper basins like Indo-Gangetic basin and large urban centre. This paper presents Multichannel analysis of Surface Waves (MASW) tests carried out at Lucknow urban centre, capital city of Uttar Pradesh, which lies in Indo-Gangetic basin. 50 MASW surveys have been carried out and in addition, 12 numbers of conventional bore holes were drilled with SPT tests at different depth intervals. These tests were done as part of the study of seismic microzonation of Lucknow urban centre. Additional SPT data were also collected from couple of geotechnical firms in the study area. Out of these data, 14 pairs of data consisting of MASW and SPT tests in boreholes were close to each other. Based on Vs profiles from MASW tests, it has been observed that Lucknow urban centre belong to site class D and C, as per NEHRP classification. Similar classification was also attempted from SPT data. Further, from these 14 sets, about 220 pair of data of uncorrected SPT-N value and V s were compared and correlated. Through a regression analysis, an empirical correlation was obtained between SPT N values and Vs values for the region under study. The summary of correlation developed and its comparison with similar correlation available in literature are also presented in the paper. Keywords: Site classification, Shear wave velocity, Multichannel analysis of Surface Waves (MASW) test, Standard Penetration Test (SPT) 71

102 S9_C7 Site Response Studies in the Andaman and Nicobar Islands K Sushini (E- mail: Namita Pegu, N. Purnachandra Rao, M. Ravi kumar (National Geophysical Research Institute (Council of Scientific and Industrial Research)Uppal Road, Hyderabad ) Site- response in the Andaman and Nicobar Islands region is investigated using the standard Nakamura technique. The predominant frequencies (f 0 ) of the uppermost layer and the site amplification are estimated at broadband stations along the Andaman- Nicobar Islands, based on the H/V spectral ratios. The method was applied on ambient seismic noise time-series as well as on earthquake waveform data recorded at all seismic stations. Ground amplifications up to 2 or 3 times are estimated predominantly in the frequency range of 3 4 Hz. Also considerable amplifications are seen at 7 Hz. The obtained results were also correlated with the local geology, the observed macroseismic intensities and with the theoretical estimates of resonant frequencies.the thickness of the soil layer (h), obtained from bore logs and the soil layer resonance frequencies (f 0 ) determined from the H/V spectral peaks are used to obtain a regression relation given by. This relation can be used for estimating the depth to bedrock in the Andaman Nicobar Islands using microtremor data at locations where borehole data is not available. S9_C8 Analysis of Embedded Pipeline Induced by Earthquake Excitation under Various Soil Material Types Goktepe F. ( Kuyuk H.S. ( Celebi E. ( (Department of Civil Engineering, Sakarya University, Sakarya, Turkey) Earthquakes have destructive influences onto lifeline engineering and especially leading to considerable economic loss to the underground structure. Underground structures are significant unit of lifeline engineering. The Southern Caucasus- Eastern Turkey energy corridors are formed by several critical pipelines carrying crude oil and natural gas from Azerbaijan, via Georgia, to Turkey and world markets. Many project accomplished and construction of new corridors are still going on. This study is dealt with the modeling and assessment of embedded pipelines under various soil material types such as Linear-elastic model, Mohr-Coulomb model and Hardening soil model induced by earthquake excitation. Due to difficulties in setting up experimental studies and high expenditures, discrete computer models used for numerical simulation considering soil- infrastructure interaction effects via a two dimensional (2D) finite element method in time domain (Figure 1). Absorbent boundary that doesn t reflect seismic waves in the numeric soilinfrastructure model was used. Comprehensive analyses for embedded pipeline are performed and obtained results are evaluated. Figure 1. The typical numerical model FE-mesh with pipeline Keywords: Embedded pipeline, dynamic FE analysis, soil-infrastructure model, soil material type. S9_C9 Seismic Hazard Assessment of Gujarat K. S. Vipin 11, T. G. Sitharam 2 and Sreevalsa Kolathayar 3 ( 1 Post Doctoral Fellow, 2 Professor and 3 Research Scholar, Department of Civil Engineering, Indian Institute of Science (IISc) Bangalore ) The state of Gujarat falls in seismic zone V of the Indian seismic code BIS-1893(2002). Incidentally this is the only region in the stable continental shield which is in seismic zone V. This indicates the importance of carrying out a seismic hazard assessment for the Gujarat region. More over the Bhuj earthquake in 2001 is the deadliest continental shield earthquake ever occurred. This paper tries to evaluate the seismic hazard of the state of Gujarat based on Probabilistic Seismic Hazard Analysis (PSHA) January, 2011

103 method. The earthquake catalogue for Gujarat will be prepared by collecting the data from national and international agencies. The seismic source identification - both linear and areal will be done and using these two types of sources, the hazard assessment will be carried out. In addition ot the two types of sources, multiple attenuation relations will also be used and these different models will be combined using a logic tree approach. The hazard assessment will be done with a grid size of 10 km x 10km. Maps showing the spatial variation of peak horizontal acceleration (PHA) values for different return periods at bed rock level for the entire state will be presented in the paper. The response spectra for selected cities will also be developed. S9_C10 Earthquake Hazard Assessment for Public Safety Lalliana Mualchin ( Retired Chief Seismologist, Office of Earthquake Engineering, California Dept. of Transportion, Sacramento, California and Seismic Consultant to the Govt. of Mizoram, India, Disaster Mangement & Rehabilitation Dept., Govt. of Mizoram, Aizawl) Catastrophic disasters are usually caused by large earthquakes to the unprepared community and whose structures are not designed and constructed to withstand the earthquake hazard load. Earthquake science provides the framework for assessing the hazard. The use of realistic estimates of hazards from potential large earthquakes for designing and constructing structures is one of the keys to public safety. The traditional approach of earthquake hazard estimate is straightforward, defining the largest earthquake (maximum credible earthquake, MCE) magnitude that each of the considered sources/faults or areas can generate using (1) empirical relationships between magnitudes and fault lengths or areas for various fault types, or (2) seismicity. Hazard (e.g., vibratory strong ground motions) at a site or an area is estimated by applying the magnitudes and distances to the adopted attenuation relationships which show ground motions (e.g., peak ground acceleration) as a function of distance for various magnitudes. The use of the largest potential earthquake magnitude supercedes or automatically considers all the smaller events. Another approach have been introduced mainly to define equitable hazards from the sources and also to reduce uncertainties in various steps of the assessment procedure. The rarity or unlikely occurrence of MCE during the life of structure as well as too high cost for using MCE have been another motivation for the new approach which is known as probabilistic seismic hazard analysis (PSHA). To distinguish it from PSHA, the traditional approach is renamed deterministic seismic hazard analysis (DSHA). Without debates or discussions on the merits of PSHA, it has been formalized and heavily promoted in California, including its use in the U. S. nuclear powerplant regulations and in the Global Seismic Hazard Map (GSHAP) project, even though DSHA is favored and continously used by engineers. Features of the approaches, including undebated rarity and cost factors, from the point of view of a practitioner for public safety will be given. Errors recently found in the theoretical foundation of PSHA by Jens Klugel and others; its unrealistic results in recent critical projects and observations will be presented. Too low hazard estimate noted for recent damaging earthquakes, particularly in a relatively low seismic-active regions such as in the Peninsular India or for the slow slip-rate faults in southern California, e.g., the 1992 Landers, 1994 Northridge and 1999 Hector Mine earthquakes, as well as for the Kobe 1995; Gujarat, 2001; Algeria 2003; Iran 2003; China 2008; and Haiti 2010 earthquakes are noteworthy. In contrast, DSHA results continue to be considered realistic and reliable for engineering. Finally, problems encountered and progress in the development of a deterministic seismic hazard map for the state of Mizoram, within the highest seismic zone V in India, will be discussed to show the need to do earth science study and to record strong motions in such remote and highly seismic-active regions of the world. Various ideas on the nature and geometry of the Indo-Myanmar subduction zone will be presented as the dominating structure. The unrealistic GSHAP map for the region in consideration of the dominant earthquake source zone may do more harm than good in misleading the community January,

104 S9_P1 Geo-informatics based conceptualization of Earthquake Disaster Management System Ajeet P. Pandey ( R.K. Singh, A.K. Shukla (Earthquake Risk Evaluation Center, India Meteorological Department, New Delhi) The whole world today is highly prone to disasters, risks and uncertainties than ever before. A large proportion of humanity is constantly at risk due to deteriorating environment, climatic variability, growing population and the increased frequency of sudden natural catastrophes. Recent years have witnessed alarming increasing trend in occurrence of natural disasters as well as their magnitudes of impact. In India, there had been several natural catastrophic disasters like Cyclones, Earthquakes, Tsunami, Floods, Draught, Landslides and Forest Fire etc which have severely been affecting the country for many decades. Super Cyclone in Orissa, Earthquake in Kachchh Gujarat and recently occurred Tsunami in the Indian Ocean originated due to the Great Sumatra earthquake are the most devastating disasters that country has witnessed in the recent past. Study reveals that in India most disastrous catastrophe amongst all these are Earthquakes, which devastate the country by killing several hundreds of human lives, rendering thousands of people homeless and destroying enormous Public and National Properties. An efficient GIS based near real time earthquake disaster management is indeed the need of the hour to tackle this frightening situation in the country. Geo-informatics is a powerful tool that develops and uses information science infrastructure to address the problems of geosciences. Geo-informatics combines geospatial analysis and modeling, development of geospatial databases, information systems design, human-computer interaction and both wired and wireless networking technologies. It primarily includes Remote Sensing (RS), Global Positioning System (GPS) and Geographical Information System (GIS) that have become an integrated, well developed and successful tool in disaster management. Geo-informatics, in recent years, has been the subject of consideration with regards to disaster management programs worldwide. In this paper, role of geoinformatics as a powerful tool for collecting, storing, retrieving, transforming, displaying and disseminating spatial data from a real world is discussed in context to earthquake disaster management. It emphasizes on the application of Remote Sensing and GIS for the preparation of multithematic maps using various spatial, non-spatial and attributes data with regards to preparedness, prevention, planning/mitigation, rescue and relief against the disaster. Digital image processing on one hand facilitates to analyze and capture the space data for geology, geomorphology, land use/land cover, drainage pattern, slope & aspect, palaeochannel mapping, seismotectonics and image classification of the study area. At the same time GIS provides a powerful platform to utilize and handle efficiently those data for spatial analysis and integrating them to prepare digital thematic maps with high precision that finally strengthens the decision support mechanism. This paper conceptualizes the near real time earthquake disaster management system in perspective of geo-informatics that would help minimizing the effects of earthquakes significantly. Key words: Geo-informatics, Remote sensing, Digital image processing, GIS, Earthquake, Thematic maps, Disaster management. S9_P2 Probability of Occurrence of Largest Earthquakes in Jharkhand and nearby Region in Different Periods Based on Gumbel s Theory Akash Adwani, Deepanshu Melana, Yogesh Arora ( and VK Srivastava (Dept. of Applied Geophysics, Indian School of Mines, Dhanbad (India) The state of Jharkhand plays an important role in the progress of India as it is rich in coal and other mineral resources and many important industries have come up which are growing at a faster rate than expected. Therefore though the seismic risk in the region is apparently low but never the less it cannot be ignored and needs to be studied for the safety of the properties and life from any such eventuality. So in order to ensure the safety it is necessary to study the pattern of occurrence of January, 2011

105 earthquake and associated risk using the appropriate statistical tools. In general the seismicity characteristics of the Jharkhand resemble those of Stable Continental region (SCR) as is observed for southern peninsular region of the Indian sub continent. The state has experienced nearly 30 earthquakes in the past and having magnitude ranging from 3 to 6 during last 147 years. These earthquakes are of shallow/crustal in nature and is scattered all over the area. It can be seen from the seismicity map that the frequency of the earthquakes has been increasing since the year 2000 and hence this requires quantitative analysis of pattern of occurrence as well calculation of associated seismic risk in the region. In present paper statistical approach of Extreme Value method as described by Gumbel (1958) has been applied by taking data set of data of the year 1862 to 2009.As it appears that the data set may not be complete we choose this method utilizing the largest observed earthquake in a time span. This method has been applied for various other regions of world by various workers viz.; Karnik and Schenkova, 1974; Tezcan, 1996; Ozmen, et al, 1999; From the present study it has been concluded that the seismic risk in the region has increased and since then there is high probability of occurrence of seismic events of magnitude in a range of 4 to 5 in a period of 50 years which decreases as we go for higher magnitudes. Also the return period is quite high as we move on to greater magnitudes like 6 to 7 (70 to 230 years) but for lower magnitudes it is still a matter of concern (7 to 22 years). However as our period of the data taken is small considering tectonic history of the region one has to consider applying technique of paleoseismic study in order to delineate active seismotectonics in the geological past and thus understanding the seismicity pattern and associated risk in the region. S9_P3 Preliminary Site Characterization through Integration of Geophysical and Geotechnical Data at Gujarat International Finance Tech City, Gandhinagar in Gujarat, India B.K. Rastogi, A.P. Singh, Sandeep Agrawal, Sumer Chopra, B. Sairam, Kapil Mohan, January, 2011 Janki Desai, Luangmei Limpou, Maibam Sarda, Ranjana Noarem, Jaina Patel, Pooja Ramanuj, Ashish Bhandari and Surya Prakash (Institute of Seismological Research, Raisan, Gandhinagar , Gujarat, India.) Geophysical and Geotechnical investigations are used for site characterization studies at Gujarat International Finance Tech (GIFT) City, Gandhinagar in the Gujarat state. The investigations have been carried out at around 506 acre of land at Gandhinagar. The proposed Buildings for construction are multistoried township and corporate offices. The ground and height of building will exceed 80 stories (100m and above). Here geophysical investigations like Microtremor array survey, Multichannel analysis of surface wave (MASW), PS-logging and Earthquake observations have been carried out at well distributed site to determine the site amplification corresponding to the amplified frequencies and the relevant shear wave velocity profile of the deep sedimentary basin. Furthermore, geotechnical investigations as SPT N-values, grain size analysis, litholog analysis are done at locations of geophysical observations. From these combined studies, we have observed various geological boundaries with depth like Holocene1-Holcence-II, Holocene-Pleistocene, Quaternary-Tertiary and Tertiary-Deccan trap. We have also estimated the Engineering Bed Rock (EBR) according to soil type and shear wave velocity structure. At GIFT City (Gandhinagar), an impedance contrast is observed at 400 m depth for frequency of Hz with 3 times amplification, which may be due to Quaternary-Tertiary boundary. Another peak is observed at the frequency of 4Hz with 2-3 times amplification due to Holocene I Holocene II boundary at 40 m depth. Resonance frequency of 1.5Hz corresponds to Holocene-Pleistocene boundary at 150m depth, which is taken as EBR being omnipresent. In addition, the earthquake records show a peak at around 0.1Hz; this could be due to Tertiary- Deccan trap boundary at 4000 m depth. Integrated geophysical and geotechnical results show that the upper most layer up to 0-40 meters has the low shear velocity between m/s. The second layer is to the depth of meters 75

106 with shear velocity m/s and the third layer is to depth of m with shear velocity m/s. These layers may be suggested to be Quaternary deposits of Holocene I, Holocene II and Pleistocene. By definition the EBR should be uniformly distributed and beneath EBR there is less variation of structure and properties. From these considerations, the boundary of Holocene- Pleistocene at around 150 m is considered to be EBR. S9_P4 Preliminary Site Characterization through Integration of Geophysical and Geotechnical Data at Dholera Special Investment Region in Gujarat, India B.K. Rastogi, A.P. Singh, Sandeep Agrawal, Sumer Chopra, B. Sairam, Kapil Mohan, Janki Desai, Luangmei Limpou, Maibam Sarda, Ranjana Noarem, Jaina Patel, Pooja Ramanuj, Ashish Bhandari and Surya Prakash(Institute of Seismological Research (ISR), Raisan, Gandhinagar , Gujarat, India.) Geophysical and Geotechnical investigations are used for site characterization studies at Dholera Special Investment Region (DSIR) between Ahmedabad and Bhavnagar in the Gujarat state. Here geophysical investigations like Microtremor array survey, Multichannel analysis of surface wave (MASW), PS-logging and Earthquake observations have been carried out at well distributed sites to determine the site amplification corresponding to the amplified frequencies and the relevant shear wave velocity profile of the deep sedimentary basin. Furthermore, geotechnical investigations as SPT N-values, grain size analysis, litholog analysis are done at locations of geophysical observations. From these combined studies, we have observed various geological boundaries with depth like Holocene1-Holcence-II, Holocene-Pleistocene, Quaternary-Tertiary and Tertiary-Deccan trap. We have also estimated the Engineering Bed Rock (EBR) according to soil type and shear wave velocity structure. At DSIR, H/V spectral ratios using ambient vibrations and earthquake records indicate dominant frequency range Hz, corresponds 4-6 times amplification. If the thumb rule apply f=vs/4h for the thickness of the layer is applied for the Vs profile at the sites, the depth corresponding to such frequency is around 350m depths of Deccan Trap, when average shear wave velocity for Tertiary is set to be 700m/s. This is justified by depth of 354 m at which Deccan Trap is encountered by ONGC. Other peaks present are at frequency range 1-2 Hz and 4-6 Hz with around 2 to 3 times amplification. These dominant frequencies can be interpreted as shallower layer of impedance contrast at boundaries of Pleistocene-Holocene and Holocene I-Holocene II layers. Integrated geophysical and geotechnical results at DSIR show that the upper most layer up to 0-30 meters has the low shear velocity between m/s. The second layer is to the depth of meters with shear velocity m/s and the third layer is to depth of m with shear velocity m/s. These layers may be suggested to be Quaternary deposits of Holocene, Pleistocene and Tertiary. The shear wave velocity of the last layer is m/s corresponding to Deccan Trap. The boundary of Pleistocene-Tertiary at around 80 m is considered as EBR at DSIR as it is uniformly distributed in the area and under it there is less variation of structure and properties. The Second layer is soft soil while the third is soft rock. S9_P5 Estimation of Liquefaction Potential of Dholera Region Based on SPT N-values Sarda Maibam ( Ranjana Naorem, Pooja Ramanuj, Jaina Patel (JRFs) (Institute of Seismological Research, Raisan Village, Gandhinagar ) Liquefaction is known as one of the most destructive phenomena caused by earthquakes and has been widely seen in saturated soil deposits (Niigata, 1964; Alaska, 1964; Tangshan, 1979; Loma Prieta, 1989; Kobe, 1995, Turkey, 1998; Chi-Chi, Taiwan, 1999). Liquefaction may be defined as the transformation of a granular material from solid state to liquid state due to increase in pore pressure and reduced effective shear strength and will behave more like a fluid (Marcuson 1978).The purpose of this study is to determine Liquefaction Potential of Dholera SIR. The required parameters for estimating liquefaction January, 2011

107 potential are lithology of the area, geotechnical soil properties (fine content, plasticity index, D 10 and D avg ), converted Standard penetration resistance value (N 1 ) 60, ground water level, Horizontal Seismic Coefficient (k h ). In the study area, 87 boreholes were drilled, out of which 80 boreholes were taken into consideration for estimating liquefaction potential. Penetration corrections were carried out for the SPT N-values greater than 100 in order to get the absolute N value (N c ) and for normalization of overburden stress to achieved standardized value of (N 1 ) 60 (Robertson & Fear, 1996). Considering our available geotechnical data, the Japanese Road Association Methodology was used for the estimation of the liquefaction potential. The methodology comprised of two steps namely F L and P L estimation. In this study, the earthquake type was decided based on the parameter C w (Correlation coefficient for earthquake), adopted as Type 2 (Type-1=Inter-plate; type-2=intra-plate earthquake type) as according to the seismotectonic context of the scenario earthquakes in India. F L estimation calculates a safety factor for each borehole down to depth of 20 m, which is the most susceptible zone for liquefaction. Liquefaction potential for each grid is evaluated by the P L estimation, for pre & post monsoon period. According to Iwasaki et al. (1982), sites with P L values e 15 suffer severe liquefaction effects and with P L < 5, least liquefaction. The liquefaction potential of Dholera SIR is very low i.e 0d PLd 3, except only at one site which shows very high potential i.e P L =32.7(on east-central part, which is in vicinity of the Gulf of Cambay). A total of 20 borehole sites are non-liquefiable. Among the 60 liquefiable boreholes, 54 have very low (P L =0), 5 have relatively low (0 < P L <= 5) and one is relatively high (P L >15) for the Dholera SIR. S9_P6 Vs30 and Site Amplification studies in Dholera SIR Region, Gujarat, India B. Sairam( B. K. Rastogi, Sandeep Aggarwal, K. S. Roy, Kishansinh Zala, Mehul Jagad and Vandana Patel (Institute of Seismological Research, Raisan Gandhinagar) In order to clarify the dynamic soil property of Dholera region, Shear-wave velocities (Vs) were measured by Multichannel Analysis Surface Wave (MASW) (41 sites) and Suspension PS-logging (16 sites) in Dholera SIR. These sites are well distributed in the area and covered three geomorphological units viz New-Mud Flat (NMF), Salt-Flat (SF) and Old- Mud Flat (OMF) of the study region. Standard Penetration Test (SPT) was also carried out at each PS-logging site. The PS-Logging results show good correlation with SPT N-values. Most of the 1-D Vs profiles by MASW and PS-logging show that Vs increases steadily from nearly 200m/s at near surface to 400m/s at 30m depth. Average of Vs within 30 m depth (Vs30) of all sites of study area is in the range of 190 to 340 m/s. In view of this, the study region can be classified as D-class according to the NEHRP classification. Maximum depth up to which Vs is measured by the PS-logging is 84 m and by the MASW is 69 m. Contours of the Vs30 are showing good correlation with all three geomorphological units of the region. The NMF has lowest Vs30 (Vs30 ~ m/s) while the OMF has highest Vs30 ( m/s) among all the geomorphological units in the study region. The Vs30 of the SF is m/s and is higher than those at the NMF. Further, Site Amplification (SA) has been estimated using earthquake records at 11 sites. The sites of SA were well distributed and covered all three geomorphological units of the study region. SA up to 6.7 is observed in frequency range of Hz. SA of the NMF, the SF and the OMF are in the range of 6-6.7, and respectively. A plot of Vs30 versus SA is showing that amplification increasing with decreasing Vs30. The geomorphological units which have low Vs30 are showing higher SA while those units which have higher Vs30 are showing low SA. From above observations it is inferred that Vs30 is good proxy for site amplification January,

108 S10: Tectonics and Crustal Movements Convener : B.K. Rastogi THEME The knowledge about the tectonics and crustal movements is essential for medium and long-term assessment of seismic hazard. Various geophysical surveys determine crustal and upper mantle structure including sedimentary thickness, faults orientation, basement block structure, Moho depth. Passive methods like seismic tomography receiver transfer functions, shear wave splitting provide some more details like discontinuities in the upper mantle which provide clues for deeper earth processes like hot spots and disposition of plutonic bodies which act as stress concentrator or poisson s ratio to detect fluid field zones which act as asperities or lithosphere-asthenosphere boundary which provides clues for rifting episodes. The results of VLBI, GPS and InSAR measurements are inferred in term of current crustal movements and after a major earthquake pattern of deformation in respect of shear deformation or visco-elastic process/ rheology change. The session includes papers on such aspects. S10_I1 Seismotectonics and velocity structure of the Kumaon - Garhwal Himalaya P. Mahesh 1 ( S.S. Rai 1, Sandeep Gupta 1, Rajgopal Sarma 1, Ajay Paul 2, K.S. Prakasam 1 ( 1 National Geophysical Research Institute (CSIR), Hyderabad, India, 2 Wadia Institute of Himalayan Geology, Dehradun, India) We present the detailed seismicity pattern, earthquake mechanics and velocity image of the Kumaon-Garhwal Himalaya. We use local earthquakes recorded during April 2005 to June 2008 by a temporary network of 51 broadband seismic stations operated by the National Geophysical Research Institute (NGRI, 40 stations) and Wadia Institute of Himalayan Geology (WIHG, 11 stations). 1-D velocity model for the region is generated using VELEST with 385 local earthquakes each with at least 8P and 5S phase readings and azimuthal gap <180. This 1-D velocity model is used to relocate all the recorded 1250 earthquakes. The majority of earthquakes follow the trend of the MCT zone, however, we also observe earthquakes beneath the Ganga basin, lesser Himalaya, higher Himalaya and further north of the STD. Further refinement of the hypocentral parameters using HypoDD relocation program results well constrained locations. Though the majority of earthquakes have their genesis in the upper crust (up to 20 km), significant number of earthquakes are located in the mid-lower crust, as well. Unlike the Nepal Himalaya, we have no reliable earthquake in the shallower mantle suggesting a lateral diversity in the rheological property of the Indian lithosphere under-thrusting the Himalaya. The focal mechanisms are predominantly of thrust mechanism. The P-axis directions of earthquake focal mechanisms are clearly oriented along the north-northeast trending direction of Indian plate motion with respect to Eurasian plate. The maximum compressive stress direction is NE-SW oriented, consistent with the relative plate motion of the Indian plate. We also determine 3-D seismic velocity and Poisson s ratio variations using local earthquake tomography. We observe 6-7 km thick zone of low- Vp, low-vs and high Vp/Vs in the upper crust beneath HFT, and attribute it to sediments in the region. This low-vp zone smoothly dips in the north and suddenly dips significantly beneath MCT. The dipping of this low-vp can be the expression of upper part of the down going Indian crust. Vp in mid crust is generally low, while the Vs is high. It appears that the cause of much of this complexity may be due to the change in velocity distribution in the upper 6 km to below 20 km depth. Therefore, 6-20 km depth zone may be viewed as a transitional layer containing contributions from structure above and below it January, 2011

109 S10_I2 New Evidence of the Involvement of the Low Density Fluid Phase in the Deep Crust Seismicity M.V. Rodkin (International Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Science, Profsoyznaya Str. 84/32, , Moscow, Russia, The deep fluid is suggested to have important role in the deep crust and upper mantle seismicity. However few direct evidences of the fluid involvement in the deep crust and upper mantle seismicity are known. The differences in the earthquake depth and origin time values obtained in the examination of first arrivals and in result of seismic moment calculation were examined. For the case of moderate size and strong earthquakes these differences becomes to be comparable with the measurement errors and their statistical examination is available. The difference in the origin time values obtained from the first arrivals examination and from the seismic moment solution was treated as an estimate of semi-duration of the failure process in the given earthquake. The difference in the depth of the earthquakes obtained from the first arrivals examination and from the seismic moment solution was treated as an estimate of half-size of the failure zone in depth. The earthquakes were subdivided into two groups with the seismic moment depth values exceeding and being less than the depth values obtained from examination of the first arrivals data. These groups of earthquakes are treated as earthquakes with process of failure development to the Earth s surface and to the depth. It was found that these two groups of earthquakes have different statistical characteristics. The earthquakes which develop to the Earth s surface have in the average lower apparent stress values, lower duration time, and greater extension on depth. These earthquakes essentially predominate in the depth interval from 10 to 25 km depth. The revealed features of such earthquakes can be caused by the deep fluid of low density existing in the earthquake rupture zone. This fluid will have a strong tendency of uprising to the Earth s surface and will promote the failure process in this direction. The predominance of such earthquake in the mentioned January, 2011 depth interval can be connected with the development of different dehydration reactions expected to occur in this depth interval. The other display of the same effect could be the known feature of concentration of earthquake hypocenters in the narrow sub vertical nail-like structures revealed earlier in the seismicity of the Japan Islands and in other regions. S10_I3_ Crustal configuration and seismo-tectonics of the Kutch Rift Basin from analysis of aeromagnetic Data Mita Rajaram( and S.P.Anand(Indian Institute of Geomagnetism, NewPanvel(W), Navi Mumbai.) The Kutch rift basin of Gujrat (Zone V) has witnessed occurrence of high intensity earthquakes; the catastrophic Bhuj earthquake of 26 th Januray 2001 with magnitude Mw 7.7 (Ms8) being the most damaging in the last 50 years. Recently, high resolution aeromagnetic (HRAM) total magnetic field data were collected by Directorate General of Hydrocarbons over the Kutch Rift Basin. The objective of the survey was to acquire high resolution magnetic data to map the anomalous magnetic field distribution pattern in order to understand the lithology and sub surface structural settings in aid of geological interpretation. The aeromagnetic anomaly map depicted signatures of several major geologic and tectonic units including the trap flows, the Kutch Main land Fault, the volcanic islands etc. From this analysis we were able to bring out signatures of several hitherto unknown faults and intrusives. Analysis of the data suggests that the shallow level magnetic sources are related to trap flows and volcanic plugs. For the first time we were able to isolate the trap flows to the northwest of Kutch Mainland fault. We find that the epicenter of the main shock of Bhuj earthquake lies on the intersection point of three identified faults; the epicenters of aftershocks fall on the NW-SE and NE-SW faults emanating from the main epicenter and these are constrained to lie within an area defined by the faults identified from the aeromagnetic data. Further, these faults are related to the directional change of the compressional forces on either side of the Bhuj epicenter, as 79

110 evidenced in the GPS data.. A magnetic source distribution map along with the depth to the various tectonic units has been generated. Results of analyses and modeling of the aeromagnetic data will be presented. S10_C1 Seismotectonic Studies of Kachchh Basin using Gravity surveys after 2001 Bhuj Earthquake Rashmi Pradhan, R.K. Singh, Siddhart Dimri and Mehul Jagad (Institute of Seismological Research, Gandhinagar.) The structural configuration of Kachchh basin is characterized by highlands and plains, which represent area of uplifts and half-graben, respectively. The uplifted blocks are bounded by E- W trending major faults, prominent among them being Kathiawar, KMF and Island Belt fault. The Bouguer anomaly of Kachchh shows several gravity highs and lows, primarily attributed to fault controlled basement uplifts and depression. It is also suggested by gravity surveys that there is larger thickness of sediments towards south and a general uplift of basement towards north, descending stepwise towards the south, indicating post rift vertical tectonics. The Bhuj earthquakes of 26 th January 2001 and its aftershocks and migrated earthquakes are concentrated in the zone of thrust faults KMF, South and North Wagad faults and NW-SE and NE-SW structural trends. The Bouguer gravity map of Kachchh represents the following features: Zero contour between gravity high and low, is running almost W-E direction up to Bhachau, representing KMF. The Zero contour of gravity taking almost S-N turn after Bhachau suggesting NW-SE boundary of an uplifted block near Manfara (South Wagad Fault) and NE-SW turn near Chobari (North Wagad Fault). The zero contour of Bouguer map near Desalpar may be representative of Gedi Fault and positive gravity region close to Desalpar may be due to presence of mafic/ultramafic bodies which needs to be verified by magnetic survey. The N-S orientation of zero contour adjacent to Umrapar may be representative of Basement fault which separates the Khadir and Bela islands. Basement upliftment (crustal deformation) is well reflected in the form of gravity high within gravity high zone in and around Dholavira The trend of regional gravity anomaly shows that the Kachchh basement is dipping towards SE. S10_C2 About the Geophysical studies are being carryout by WIHG in the NW Himalaya and the obtained preliminary results. Sushil Kumar 1 ( Rama Sushil 2 and Ajay Paul 1 ( 1 Wadia Institute of Himalaya Geology, 33 GMS Road, P.B.No.74, Dehra Dun (UA), India. 2 SGRRITS, Dehra Dun (UA), India.) The Himalaya originated as a result of continent continent collision between India and Asia. The northward convergence of India resulted in crustal shortening of the northern margin of the Indian continent, accommodated by south-verging thrusts. The principal thrusts, namely the Main Central Thrust (MCT), the Main Boundary Thrust (MBT) and the Himalayan Frontal Thrust (HFT) show younging age and shallowing depth, suggesting southward migration of the main deformation front. Neotectonic activity and active faulting related to the thrusts are observed on the surface in some restricted segments. The MCT remains largely inactive, except some reactivated segments showing lateral strike-slip movement as in Central part. The MBT in certain localized areas exhibits neotectonic activity. The Himalayan Frontal Thrust (HFT) shows active faulting and associated uplift. The HFT represents a zone of active deformation between the Sub- Himalaya and the Indian plain. It is well known that the frontal Himalaya has been the site of several devastating earthquakes. Considering that in case of preparation period for a future large earthquake, certain precursory activities can be expected. The understanding of earthquake source processes and the medium characterization are the tools for the assessment, mitigation and reduction of seismic hazard. To achieve these objectives the Geophysics January, 2011

111 Group of Wadia institute of Himalayan Geology (WIHG) has been operating a regional seismic network in NW Himalaya since Presently, this seismic network has 38 broadband (BBS) and 7 short period seismic stations. 12 BBS stations of this network are connected through VSAT to monitor regional seismicity in real time mode at central station Dehradun. The Geophysics Group has carried out first ever passive seismological experiment around the Eastern Himalayan Syntaxis. A linear profile of 12 broadband seismic stations has been installed in Lohit Valley, Eastern Hiamalayan Syntaxis for studying the lithospheric structure and dynamics of the syntaxis. Investigation of geodynamical deformation and Crustal/Lithospheric structures of the Himalaya and surrounding regions is being carried out by quantitative physical methods viz Seismological studies, Global Positioning System (GPS) and electromagnetic methods. Besides these, Multichannel Analysis of Surface Waves (MASW) and site response studies in major populated centers/ cities of northern India have been carried out which are prime input to the microzonation studies. In this paper all the experiments and their preliminary results will be discussed. S10_C3 Fractal Dimension and b-value Mapping in NW Himalaya and adjoining regions. Sushil Kumar 1 ( Rama Sushil 2 and Ajay Paul 1 ( 1 Wadia Institute of Himalaya Geology, 33 GMS Road, P.B.No.74, Dehra Dun (UA), India. 2 SGRRITS, Dehra Dun (UA), India.) The northwest Himalayan region and the adjoining regions fall in the most intense seismic zone. Earthquakes of varying intensities have hit the region in the past and similar threats remain imminent. In the last 105 years, the main earthquakes occurred are the Kangra earthquake of 1905 (Ms=8.0), the Kinnaur earthquake of 1975 (M=6.8), Dharchula earthquake of 1980 (Mw=6.5), Uttarkashi earthquake of 1991 (Mb=6.6), Chamoli earthquake of 1999 (Mb=6.8) and the Kashmir earthquake of 2005 (Mw=7.6), which resulted in tremendous loss of life and property. The earthquakes occurrence possesses non-linear relation with respect to space and size. Fractal dimension and b-value are determined from January, well-located earthquakes, recorded at 9-19 seismic stations in Northwest Himalaya during A detailed study of the frequency magnitude distribution and fractal dimension as a function of depth has carried out. In this paper, the results obtained have discussed. S10_C4 Stress Pulse Migration by Viscoelastic Process for Long - distance Delayed Triggering of shocks in Gujarat after the 2001 Mw 7.7 Bhuj earthquake B.K. Rastogi (Institute of Seismological Research, Gandhinagar , India, The Gujarat region in western India is seismically one of the most active intraplate regions. It was known to have low seismicity but high hazard in view of the occurrence of several large earthquakes but fewer moderate or smaller shocks. The scenario changed during the first decade of the 21 st Century when a damaging earthquake of M~5 with a long sequence of shocks occurred in Bhavnagar in the year 2000 and M7.7 great earthquake accompanied by 10,000 located aftershocks of Me 1. Additionally, 30 felt mainshocks (of M4 or so) occurred at 20 different locations in Kachchh and Saurashtra. In contrast the earlier twenty decades experienced hardly one or two felt shocks (barring the year 1938 when 5 earthquakes of M4-5 were felt at Paliyad in Saurashtra). The Gujarat region has E-W trending major faults of the failed Mesozoic rifts of Kachchh and Narmada which are getting reactivated by thrusting. There are some smaller transverse strikeslip faults. South of Kachchh, in the Deccan Volcanics of Saurshtra, the NW and NE trending smaller strike-slip faults are also activated in the form of moderate earthquakes in response to the platetectonics stress. Aftershocks in the 2001 Mw 7.7 rupture zone in Kachchh continued up to M5.7 level until 2006 and Md 5 level subsequently with earthquakes of M>4 once every two months and five or so of M>3 every month. For two years the activity concentrated along the 2001 rupture zone of 40kmx40km with large slip. Subsequently, the hypocenters expanded to nearby areas along different faults in E-W direction (more 81

112 towards E) becoming 70kmx50km, 100kmx75km and 125kmx75km by 2003, 2004 and 2006, respectively. By 2008 the area further expanded to 200kmx80km covering South Wagad and Banni faults. Additionally the epicentral area expanded by 60 km towards NE to Gedi fault by Moreover, the activity along the Allah Bund and Island Belt faults has also increased, making most of north and east Kachchh area of 250km x150km active by 2008 with M<5 shocks. The activity had also spread towards south to Saurashtra: 120km by 2006 and 200km by 2007 along several small faults in Jamnagar, Junagadh, Porbandar and Surendranagr districts. At three sites the activity is in the form of sequences with largest shocks of M~ 4 to 5 and several hundreds of Me 0.5 shocks recorded on local networks. Only two such sequences were reported earlier during 1938 at Paliad in Bhavnagar district and during 1986 in Valsad, south Gujarat. The shear deformation for adjustment process in Bhuj earthquake zone is now negligible as deduced from only 2-3 mm/yr movements of GPS stations. Moreover, the activity after 2001 earthquake can t be explained by Coulomb stress increase as the NE expansion to Gedi area is in the zone of decreased stress, though the EW expansion was as predicted. The viscoelastic process appears to be the plausible mechanism for long distance and delayed triggering of earthquakes by migration of stress pulse generated by 2001 earthquake with diffusion rates of 5-30 km/yr or area growth of 4000 contributing stress vertically upwards from lower crust and upper mantle to distances of 200km in 6 years. S10_P1 Active deformation and lithotectonic model of Saurashtra Horst, Gujarat, India. Girish Ch. Kothyari 1*, Mukesh Chauhan 1, R. K. Dumka 1, A. K. Gupta 1, Vikas Kumar 1, B. K. Rastogi 1 and S. K. Biswas 2 ( 1* Institute of Seismological Research, Gandhinagar , Gujarat, India., 2 Flat no. 201 C-Block, ISM House, Thakur Village, Kandivali (E) Mumbai , India) Western margin of India is characterized by a rifted volcanic continental margin. It extends from Kachchh in the northwest to Cape Comorin in the southeast. Saurashtra region of Gujarat, located in western margin of Indian shield, evolved as a foundered continental block. Saurashtra is seismically one of the active regions of Gujarat and has experienced low to moderate magnitude earthquakes in the recent past. A lithosphere model is presented here using historic and recent seismic events and available 2D Bouguer gravity data. Seismic events were analyzed using Gutenburg-Richter frequency-magnitude distribution and b-value has been estimated to characterize the seismotectonic environment for Saurashtra region. The crustal movement of Saurashtra has been estimated using GPS network of Institute of Seismological Research (ISR). 2D Bouguer gravity data have been correlated with morphotectonic features in order to understand the relationship between gravity data and different geomorphic units. High gravity values in the central part of Saurashtra and low values on the north and south confirms horsts structure of Saurashtra involving basement block uplift. Several prominent lineaments are identified (Mishra et al., 2001). Distribution of historical seismicity as well as recent earthquakes and their aftershocks along prominent lineaments suggests presence of active faults along these trends. Concentration of hypocenters close to the known plutonic bodies suggests that these high density bodies perhaps acted as stress barrier for earthquake generation. It appears that even deep seated magma in the lower crust is the source of the plutonic bodies injected through the existing faults. Correlation of all the data set validates this interpretation. Accumulation of strain beneath Saurashtra seems to be mainly controlled by faults along the flanks of plutonic bodies which generates recent earthquakes January, 2011

113 S11: Earth s Interior, Structure and Dynamics Convener : M.Ravi Kumar THEME Our understanding of the Earth as a dynamic system has primarily evolved owing to development of new incisive tools to probe the Earth s interior from the crust to core, tremendous strides in acquisition of high quality data from dense observational networks coupled with enhanced computational power. Multidisciplinary knowledge accrued from high resolution studies of the continental lithosphere, nature and deformation of subducting slabs, physical and thermal state of the mantle transition zone, the lowermost mantle region and the inner core in conjunction with mineral physics experiments is continually refining the forefront of knowledge thereby unveiling the fundamental global and regional scale dynamic processes of our planetary interior. This session is intended to focus on our current knowledge of the deep structure, evolution and dynamics of the stable continental interiors and actively deforming plate boundary regions in diverse tectonic settings by bringing together researchers from a wide variety of disciplines from active and passive seismology, GPS geodesy, geodynamics, geochemistry, Magnetotellurics and mineral physics. Contributions specific to the evolution of the Indian shield and its plate boundary regions like the Himalaya, Burma and Andaman arc regions are particularly welcome. S11_C1 Spatial Distribution of Scatterers in the Crust of Kachchh Region, Western India by Inversion Analysis of Coda Envelopes. B. Sharma 1 ( E. Carcolé 2, A. Ugalde 3 and B. K. Rastogi 1 ( 1 Institute of Seismological Research, Raisan, Gandhinagar , India., 2 Universitat Politècnica de Catalunya, Dept. Enginyeria del Terreny, Cartogràfica i Geofísica, Jordi Girona 1-3, Edifici D2, Barcelona, Spain., 3 Institut Geològic de Catalunya, Balmes, , Barcelona, Spain) The three-dimensional spatial distribution of relative scattering coefficients is estimated in the Kachchh region, western India, by means of an inversion technique applied to coda wave envelopes. Data used consist of selected vertical-component, broadband recordings from 438 earthquakes with moment magnitudes M w ranging from 1.6 to 4.2 and epicentral distances up to 235 km recorded by the Institute of Seismological Research (ISR) seismic network. The results of the inversion analysis yield relative scattering coefficient estimates between ~1.3 and ~0.8. Most of the analyzed region reveals small spatial perturbations of the scattering coefficient of January, 2011 the order of, thus suggesting a uniform distribution of scattering coefficients in the lithosphere beneath Kachchh region for the scale length of the analyzed frequencies between 1 and 2 Hz. This uniformity is broken by the presence of some strong scattering areas distributed in several clusters through the region. A clear picture of the Moho in this region is imaged at average depths between 32 and 42 km. Also it is clear that in the Kachchh region the Moho discontinuity is highly disturbed maybe due the high velocity body in the lower crust and upper mantle which is consistent with similar studies in the same area. According to the outcome of the present study this high velocity body, maybe having heterogeneity itself, has an irregular shape and extended in the area throughout which is the reason of having more relative scattering coefficient in the whole region. S11_C2 Moho Depth Variation in the Shillong-Mikir Hills Plateau in North Eastern Region of India Estimated From Reflected and Converted Waves Saurabh Baruah ( Dipok K. Bora (Geoscience Division,CSIR North-East Institute of Science and Technology,Jorhat , Assam, India) 83

114 Distribution of Moho depth is estimated in Shillong and Mikir Hills Plateau of northeastern India using travel time differences between reflected P (PmP), S (SmS), P to S, S to P converted waves at the Mohorovièiæ (Moho) discontinuity and the first P and S arrivals using 203 local earthquakes recorded by regional seismic network. The Moho depth was estimated using model by Nakajima (PEPI 130:31-47, 2002), with considered epicentral distance ranged from 70 km to 250 km. Moho depth at reflection/ conversion point obtained by assuming a flat Moho and correlation of the results with geotectonics of the region are described in this paper. The reflection and conversion points are uniformly distributed in the study area which is mainly controlled by the geometry of the events and locations of the stations used in this study. A total of 966 reflected (PmP and SmS) phases arrival times from the seismograms of 180 numbers of shallow earthquakes and 70 converted (PS and SP) phases arrival times from 23 intermediate depth earthquakes are used. The magnitudes of the analyzed events range from 2.1 to 4.3 and the focal depths of 180 events range between 0 to 30 km while 23 numbers of events range between 38 to 49 km. For PmP phase, this could be identified from 0.5 to 2.8 sec after the first P-arrival. In case of SmS phase, the arrival times are observed within 1.0 to 3.5 sec after the first S- arrival.the usage of converted phases in addition to reflected phases reduces the rms of residuals of travel times from sec to sec after five iterations. It is observed that the Moho is thinner beneath the Shillong Plateau about km and is the deepest beneath the Brahmaputra Valley to the north about km, deeper by 5-6 km below the Shillong Plateau. The study indicates thinnest crust (~33 km) in the western part of the Shillong Plateau in the Garo Hills region. Key words: Reflected waves. Converted Waves. Moho discontinuity. Shillong-Mikir Hills Plateau. Northeast India. S11_C3 Seismic signatures of volcanism in the upper mantle beneath NW DVP. G. Mohan * ( M. Ravi Kumar+, Pankaj Kr. Tiwari, G. Surve, D. Saikia+ and Praveen Kumar (*Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai , + National Geophysical Research Institute, Uppal Road, Hyderabad ) Teleseismic P receiver function study was done to investigate the upper mantle discontinuities beneath northwestern Deccan Volcanic Province (NW DVP) of India, encompassing the Saurashtra horst, Kutch, Cambay and Narmada rifts, Aravalli craton and the offshore region of the Gulf of Cambay. Over 1500 high quality receiver functions from 438 events recorded by 9 broadband stations are utilized for this purpose. The arrival times of the P410s and P660s phases are observed to be delayed at most stations by H 1-1.4s relative to times predicted by the IASP91 velocity model. However, the difference in the P410s and P660s times corresponds to the global average of 24s suggesting a normal mantle transitional zone structure. Explaining a delay of 1 1.4s requires a reduction in the shear wave velocity of the upper mantle by % with respect to the IASP91 velocity model. The anomalous delays are possibly associated with a thin lithosphere coupled with thermal/compositional variations in the shallow upper mantle beneath NW DVP. Interestingly, the present results are in stark contrast to a normal unperturbed mantle beneath DVP, south of Narmada rift, imaged using a similar technique. Similarly, indications for a normal upper mantle beneath the Aravalli craton are observed, suggesting that the lithosphere beneath the cratons remain largely unperturbed by the Deccan magmatism. Contrasting seismic signatures over the rifted and stretched lithosphere of NW DVP and the undisturbed cratons of Aravalli and South central DVP respectively, are possibly linked to the flow pattern of the upwelling mantle material which is likely to be influenced by the variations in lithospheric thickness. The lithospheric architecture coupled with the reactivation of preexisting rift systems appears to have facilitated the eruption of Deccan basalts, whose source signatures are still retained intheupper mantle beneath NW DVP. Key Words: Deccan volcanic province, low velocity, mantle discontinuities, Receiver functions January, 2011

115 S11_C4 Crustal Structure and Upper Mantle Deformation in Eastern Himalayan Syntaxis: Derived from Receiver Function Analysis and Shear Wave Anisotropy Study Devajit Hazarika ( B.R. Arora (Wadia Institute of Himalayan Geology, Dehradun , India) At the eastern end of the extended Himalayan arc, the east-west trending Indian plate seems to swerves around Namcha Barwa antiform basement massif to connect to the elongated Indo Burmese arc to form the Eastern Himalayan Syntaxis (EHS). The EHS is viewed complex triple junction that joins Indian and Eurasian plates with the northern end of the Burma platelet. The present paper is an attempt to image the crustal and lithospheric structure of northeast part of Indian plate in the EHS based on receiver function analysis of teleseismic earthquakes recorded by a linear array of 11 broadband seismic stations established along the Lohit valley, cutting across eastern most part of the syntaxis. The receiver functions show an azimuthally varying lithosphere structure in the region. The majority of receiver functions for the events of NE back azimuths (30o to 90o) do not show clear Moho converted phase (Ps) depicting a very complex structure of the crust and upper mantle. In contrast to it, receiver functions from other back azimuths clearly shows Moho converted phase. The time section plot of radial receiver functions from all the stations shows a dipping structure of Moho towards east and north. The inverse and forward modeling of receiver functions yield S-wave velocity profiles marked by near surface and intra-crustal low velocity zones. The results obtained from modeling confirm the gradual increase of Moho depth in the NE-SW profile, from ~45 km at Brahmaputra valley (near Mahadevpur) to ~63 km further east of Tidding suture zone (near Walong). The dipping structure of the Moho to the north and east is consistent with the underthrusting of the Indian plate beneath Eurasia plate to the north and beneath Burma platelet to the east. The absence of Moho converted phase for the NE back azimuth support the indenter hypothesis where due to the intense crust mantle interaction, the character of Moho is lost beneath the syntaxis. The upper mantle deformation pattern in EHS is also studied using shear wave (SKS phase) splitting technique which reveals considerable strength of anisotropy with delay time s and E-W orientation of fast axis direction in most of the stations. The E-W trend of fast polarization direction is in favor of the fact that lithospheric strain induced by Indo-Eurasia collision is a primary cause of existing anisotropy. However, deviations from this E-W trend in some stations near Tidding Suture Zone indicate the influence of local (NW-SE directed) tectonic feature beneath the stations. Discrepancy of E-W trend of fast axis direction with present day crustal movement of NE India (NE directed) indicates that the crust and mantle in the region may not be completely coupled. The predominant E-W fast axis direction indicates the direction of mantle strain that continues beyond Walong thrust and connects to the N-S dominated mantle strain regime in Sichuan, SE Tibet. Although further studies are needed to establish the nature of transition in more details fulfilling the geophysical data gap between these two regions, but we assume that it reflects a transition from collision controlled deformation in NE India to deformation influenced by other forces in SE Tibet. S11_C5 The signal of transition-zone anisotropy in the normal mode coupling: Results from observations at Tibet and Taiwan. Xiao-gang HU ( Xiao-guang Hao ( (Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics, Chinese Academy of Sciences.) We investigated normal mode couplings at Tibet and Taiwan island after seven earthquakes of M w >7.8. We show that significant anomalous coupling of 0 S 20-0 T 21, 0 S 24-0 T 24 and 0 S 25-0 T 25 are often observed in the early part of vertical component records after some large earthquakes. For example, after the 2001 Bhuj earthquake, coupling pair 0 S 24-0 T 24 was observed at the LSA station (located at Lhasa, Tibet). The coupling January,

116 processes are characterized by coupled spheroidal modes having anomalous small vertical amplitudes but very large radial amplitudes. We note that strong anomalous couplings are often observed at Taiwan Island, but not any one is observed at Okinawa (Japan) stations at the same time, even these stations are less 200 km from Taiwan coastlines. Local anisotropy structure rather than Earth rotation seems more likely the cause of these anomalous couplings. According to our estimation of coupling sensitivity kernels using model of mantle anisotropy, coupling of 0 S 20-0 T 21, 0 S 24-0 T 24 and 0 S 25-0 T 25 show peak sensitivity to azimuthal anisotropy at km depth. Our findings suggest that local azimuthal anisotropy structures exist in the transition zone beneath Tibet and Taiwan. For Taiwan Island, the break-off of the east-dipping Eurasian slab beneath the Taiwan orogen is responsible for the formation of mid-mantle anisotropy. At Tibet, Indian lithosphere is subducting below the Asian lithosphere. The location of the final slab break-off is at about 400~600 km depth beneath the Himalayan-Tibetan orogen, which is responsible for the formation of transition zone anisotropy. S11_C6 Surface wave tomography across the Indian shield, Indo-Gangetic Plains and the Himalayan region using ambient noise correlation technique. N. Purnachandra Rao 1, Peter Gerstoft 2, D. Srinagesh 1, M. Ravi Kumar 1, Ch.Nagabhushan Rao 3 and B.K. Rastogi 3 ( 1 National Geophysical Research Institute, Council of Scientific and Industrial Research, Uppal Road, Hyderabad , India. 2 Marine Physical Laboratory, Scripp s Institution of Oceanography, University of California, San Diego, La Jolla California 92093, USA., 3 Institute of Seismological Research, Gandhinagar, Gujarat , India. The Indian tectonic plate is known to be underthrusting beneath the Himalaya-Tibetan plateau leading to a doubled crust a feature unique to this continental collision zone. Major international efforts have gone into comprehending the structure and evolution of the region with the help of active and passive seismic experiments like PASSCAL, GEDEPTH, INDEPTH, HIMNT and NAMCHABARWA. However these studies were mostly confined to parts of Himalaya and the Tibetan plateau region to the north, due to non-availability of seismic data from the Indian region. In the present study we apply the ambient noise correlation technique to noise data recorded by about 50 broadband seismic stations from the Sikkim and Indo-Gangetic networks near the eastern and central Himalaya respectively, the Godavari network in the Indian shield region and the seismic network of the Institute of Seismological Research in the northwestern India. Ambient noise time series of 5 months duration between station pairs are cross-correlated to obtain Green s functions for over 1200 interstation paths. It is found that the Indian subcontinent is characterized by a typical asymmetric, one-sided Green s functions indicating inhomogenous distribution of noise sources in the region, particularly a strong directionality towards south-southwest in the Indian Ocean. Group velocity measurements at periods of 10, 20, 40 and 50 seconds are used for tomographic inversion of travel times to get the velocity variations corresponding to the upper, middle and lower crust, and also the uppermost mantle structure. Variations in shear wave velocity and crustal thickness are found in the Indian shield region, the Indo-Gangetic plains and Himalaya, with clear anomalies delineating the low velocity alluvial and sedimentary zone in the Indo-Gangetic plains and a high velocity lower crust corresponding to the Son- Narmada and Godavari rift valley zones in the Indian shield. S11_C7 Anisotropy of the Indian crust from splitting of Ps phases from the Moho Narendra Kumar ( Saifur Rehman, M. Ravi Kumar, Arun Singh, N. Purnchandra Rao (National Geophysical Research Institute, Hyderabad , India) The Indian lithosphere is exemplified by its diverse tectonic activity. This is highly deformed due to the breakup of Gondwanaland since the Precambrian times. In this study, we estimate the crustal contribution of anisotropy within the Indian January, 2011

117 subcontinent through splitting of P-to-s conversions from the Moho, isolated using the conventional receiver function technique. Shear wave splitting analysis of the receiver functions from 51 broadband seismic stations located on various geological units sited on the Indian shield yielded 183 measurements. Our results reveal that the delay times lie between 0.20sec and 0.40sec consistent with those obtained from other regions globally. The distribution of crustal anisotropy within the Indian continent appears very complex with a tilted axis of anisotropy. The orientations of fast polarization azimuths at individual stations although scattered produce an average that is consistent with the strain due to the Absolute Plate Motion of the Indian plate, akin to those found from previous SKS/SKKS splitting measurements. S11_P1 A Comparative Study on Seismic Wave Attenuation Characteristics of Koyna, Chamoli and Gujarat Regions Babita Sharma 1 ( Dinesh Kumar 2, S.S.Teotia 2 and B.K.Rastogi 1 ( 1 Institute of Seismological Research, Gandhinagar, Gujarat, India. 2 Department of Geophysics, Kurukshetra University, Kurukshetra, India.) The attenuation of seismic waves in a region is caused by geometrical spreading, scattering due to inhomogeneities in the media, inelasticity and multipathing. The attenuation characteristics of a region differ from the other because of different levels of heterogeneities and inelasticity present. Therefore it is interesting to compare the attenuation characteristics of the regions with different geology and tectonic set up. The attenuation characteristics of three Indian regions, namely Koyna region, Kachchh region and Chamoli region have been compared and correlated with their tectonic set-up in the present study. Out of these three regions Koyna region shows reservoir induced seismicity alongwith the tectonic reasons. The Chamoli region is in the Himalayas which shows inter-plate seismicity while Kachchh region shows intra-plate seismicity. These regions are also important from seismic hazard point of view. The frequency dependent relationships for quality factor (Q) estimated using different parts of the seismograms are available. These available relations have been used in the present study. The frequency dependent attenuation relationships available for three regions are as follows: Koyna region Q α =(59 ± 0.5)f (1.04±.04), Q β = (71 ± 1.1)f (1.32±.08) & Q c = (117 ± 2)f (0.97±.07) Chamoli region Q á = (44 ± 1)f (0.82±.04) & Q â = (87 ± 3)f (0.71±.03) Kachchh region Q á =(77±2)f (0.87±.03), Q â =(100±4)f (0.86±.04) & Q c =(148±3)f (1.01±.02). The comparison attenuation characteristics of three regions gives better idea about the heterogeneities present in these seismically important regions. S11_P2 Inversion of Seismic Intensity Data for the Determination of Three-Dimensional Attenuation Structures in Saurashtra, Gujarat (India) Babita Sharma 1 ( Anand Joshi 2, Sumer Chopra 1 and B.K.Rastogi 1 ( 1 Institute of Seismological Research, Gandhinagar. 2 Department of Earth Science, IIT, Roorkee.) Three dimensional attenuation structure of the Saurashtra region which lies in the western part of Indian subcontinent is determined from present study. The region is a stable region in terms of seismicity although it has shown considerable events of magnitude ranging 0.5 to 5 in recent past. The 2001 Bhuj earthquake has perturbed the stress in the region and the activity in terms of earthquakes has increased near Junagadh, Jamnagar and Surendranagar areas of Saurashtra. Most of the Saurashtra falls in zone III in the Seismic zoning map of India excluding northern part which falls in zone IV due to proximity with Kachchh. The historical isoseismal data is used to obtain three dimensional attenuation structure of the region based on Q values using damped least square inversion scheme. For this purpose the isoseismal data for four earthquakes that have occurred in Saurashtra in the past having magnitude ranging from 4.0 to 5.0 have been used. The obtained January,

118 Q structure for Saurashtra can be valuable input for the purpose of seismic hazard zonation. S11_P3 Seismic evidences for Underplating and Uplifted Crust beneath the Northwestern Deccan Volcanic Province of India from Receiver Functions. K. Madhusudana Rao*( M. Ravi Kumar #, B. K. Rastogi* ( * Institute of Seismological Research, India. # National Geophysical Research Institute (Council of Scientific and Industrial Research), India. The northwestern Deccan Volcanic Province in India and associated pericratonic rift basins were reactivated during several stages of India s northward drift after the break-up of Gondwanaland during the late Triassic-early Jurassic and post collision with Asian plate. In this study, we attempt to decipher crustal thickness and average crustal Vp/Vs ratios beneath the region using the slant stacking analysis of 2776 teleseismic receiver functions from a regional network comprising 46 broadband seismic stations sited on diverse tectonic environments. Most of the receiver functions reveal clear negative phases between 0-5 s & 5-10 s after the first arrival. Results from slant stacking analysis reveals the Moho depths are varying from ( km) in the Kutch region, ( Km) in the Saurashtra region, ( Km) in the Cambay basin, ( Km) in the Narmada region and ( Km) in the north and eastern part of Cambay basin. Higher Moho depths are found under the SE part of KMU (~43.3 km) and Wagad uplift (~42.8 km) in Kutch region due to mass deficiencies from thickening of crust caused by isostatic overcompensation and also in the eastern part of Cambay basin (~41.3 km). Lower Moho depths are found beneath Cambay & Narmada rift basins and coastal areas. The shallower crust is also observed in the region surrounded by the extension of western limb of the Proterozoic Arravalli trend in Saurashtra, its eastern limb and the Narmada fault in the south. This region is observed lower Moho depth of km as compared to the surrounding regions (36-41 km) implying 3-7 km crustal upliftment. The positive buoyancy and uplift (vertical block movement) may be attributed to thermal influxing from the re-union plume after Gondwana breakup. High Vp/Vs ratios are detected beneath Kutch ( ), coastal areas of Saurashtra ( ) and NE part of Cambay basin ( ) indicating mafic/ultra mafic crust providing evidence for the extensive magma underplating beneath these regions. At all other stations, the Vp/Vs ratios are in the range of ( ) which appears to be felsic with dominance of Quartzite, similar to the global average for Precambrian shields. The Moho depths derived in our study are consistent with previous estimates from gravity and deep seismic studies (DSS). The correlation coefficients between our Moho depth values and their estimates are 0.81 for Gravity and 0.84 for DSS. The errors in the slant stacking analysis are estimated using bootstrap re-sampling technique. The errors for Moho depth and Vp/Vs are in the range of ± (2-4) Km and ± ( ). Combined with high regional heat flow, mid-crustal layers of high electric conductivity, the large intra crustal S-wave velocity reduction and the high average crustal Poisson s ratios are consistent with partial melt which may be related to the process of magmatic underplating in the lower crust beneath Kutch, coastal areas of Saurashtra and NE part of Cambay basin. S11_P4 Shear wave splitting beneath the Northwestern Deccan Volcanic Province: Evidences for lithospheric and APM related strain. K. Madhusudana Rao*( M. Ravi Kumar #, Arun Singh #, B. K. Rastogi*( * Institute of Seismological Research, Gandhinagar , India., # National Geophysical Research Institute, Hyderabad , India.) The northwestern Deccan Volcanic Province in India has witnessed several tectonic episodes resulting in the formation of rift zones, wide spread magmatism and deep seated faults that are host to some deadly intraplate earthquakes. In this study, we attempt to decipher the mantle deformation beneath the region using the SKS splitting technique applied to high quality data from a regional network comprising 36 broadband stations sited on diverse tectonic January, 2011 environments. The first measurements of 280 (207

119 SKS and 73 SKKS) splitting parameters from 73 earthquake sources reveal two major trends, one coinciding with the absolute plate motion (APM) and the other with the strike of the local geologic fabric. The Kutch rift, southern part of Saurashtra, southern part of South Gujarat and northern and eastern side of Cambay rift, reveal characteristics of ENE-WSW oriented anisotropy which is sub parallel to the Delhi Aravalli fold belt. This characteristic suggests that the mantle in these regions retains the history of Precambrian deformational structures and subsequent deformation episodes. Imprints of the Reunion plume (that is widely regarded as the source of volcanism) are absent in terms of signatures of an asthenospheric radial flow. Also, our observations are not consistent with anisotropy created by rifting process at Narmada and Cambay rifts. With the exception of large delay times (ät=1.8s) at five stations within the Kutch rift which may be due to aligned melt pockets within mantle-lid, the delay times at all other stations are close to 1s, similar to the previous estimates from other parts of the Indian shield. Previous measurements of shear wave anisotropy in the northwestern DVP have been very sparse to comprehend the mantle deformation in this region of tectonic complexity. SKS splitting measurements restricted to data from only two broadband stations (BHUJ, DHR) as a part of the continental scale study of the Indian shield anisotropy (Kumar, M.R and A. Singh, 2008) reveal small delay times of 0.6±0.3s and 0.9±0.5s with fast polarization azimuths of 62±26.5 and 30±22.5 for stations BHUJ and DHR respectively. (AMR), Bhavnagar (BHV), Lalpur (LAL), Morbi (MOR), Rajkot (RAJ), Surendranagar (SUR), Una (UNA)] by seismic network of Institute of seismological research, Gujarat (India).The period of the group velocity data ranges from 6 to 60 sec. The dispersion curves have been inverted for crustal structure using Genetic Algorithm. It gives the average crustal structure along the path. We have evaluated crustal structure of Indus block up to saurashtra having km thick crust and 4.53 km/ sec S-wave velocity. Whereas previous study of Indus block up to Bhuj indicates 44.2 km thick crust with 4.39 km/sec S-wave velocity. According to these results, we found that Kutch region is thicker then saurashtra region. Key Words: Dispersion, Genetic Algorithm, Saurashtra S11_P5 Evaluation of the crustal structure of the Indus Block up to Saurashtra using GA Inversion of Surface Wave Dispersion Vishwa Joshi ( Sandeep Aggarwal, Om Bihari, S N Bhattacharya and B. K. Rastogi (Institute of Seismological Research, Gandhinagar , India) We have computed group velocities of the fundamental mode Love and Rayleigh wave using earthquake of magnitude 5.2 MW (Lat: 39.50, Long: 73.81) recorded at 7 stations of Saurashtra [Amreli January, 2011 S11_P6 Shield like lithosphere of the lower Indus basin Evaluated from observations of surface wave dispersion. Mukesh Chauhan 1 Arun K. Gupta 1, Rashmi Pradhan 1*, G. Suresh 1**, and S.N. Bhattacharya 1*** ( 1 Institute of Seismological Research, Raisan, Gandhinagar , (Gujarat) India., 1* Ministry of Earth Sciences, New Delhi, India. 1** Seismology Division, India Meteorological Department, New Delhi , India. 89

120 1*** Department of Geology, University of Delhi, Delhi , India) The lithospheric velocity structure of the lower Indus basin has been evaluated through inversion of fundamental modes of both Love and Rayleigh wave group velocities from the broadband records of a seismic network maintained in Gujarat by Institute of Seismological Research. We have considered three clusters of wavepaths A, B and C that are mainly across the lower Indus basin from south to north; the wavepaths of A mainly cross the continental self and the wavepaths of B and C pass through the lower Indus basin. The measured group velocities correspond to periods of 5 to 90 sec for Rayleigh waves, and 5 to 115 sec for Love waves. These data sets resolve the structure of the lithosphere through a nonlinear inversion based on a genetic algorithm with a wide solution space. The mean and standard deviation of the 70 accepted solutions for each of these three clusters provide the 2-D structure for the lower Indus basin from south to north. The sediment consists of two layers with total thickness from 5.7 to 6.6 km increasing northward. The crustal thickness also increases northward from 32.9 (cluster A) to 39.7 km (cluster C) in the lower Indus region. This northward increase of crustal thickness suggests that the region is undergoing some sort of dynamic crustal adjustment, perhaps as a result of a paleogeographic environments or thermal subsidence near the Moho boundary. The S-wave velocity below the crust varies from 4.55 to 4.59 km/sec, which is close to the corresponding velocity 4.60 km/sec of the Indian shield region to the east of the Aravalli range. The thicknesses of the lithosphere, as well as the velocities of the uppermost mantle of the lower Indus plain, are similar to that of the Indian shield, but different from those of middle Indus basin. This difference supports the hypothesis of continental breakups in this region January, 2011

121 S12: Crustal Deformation through GPS and InSAR Studies Convener : V.K.Gahalaut THEME Understanding the process of occurrence of earthquakes in the plate interiors has always been a great challenge for geoscientists. These regions are characterized by very low strain rate and hence the earthquake recurrence intervals are generally very large. Such regions become centers of large inhabitation and people tend to assume that the seismic hazard in such regions is low. In such regions earthquakes occur as a surprise and cause relatively more damage, as compared to the earthquakes in the high seismic hazard regions where people are aware of high seismic hazard and take care in enforcing building codes. The 2001 Bhuj earthquake is one such best example. Thus it is important to understand the strain rate, crustal deformation through earthquake cycle, mechanism of crustal deformation, crustal structure, rheology and earthquake occurrence processes in these regions. This session is aimed to focus such studies in the Kachchh and similar other regions of the world. S12_I Weak Mantle Lithosphere in Kachchh, India Probed by GPS, InSAR and Gravity Measurements following the 2001 Bhuj Earthquake D. V. Chandrasekhar a, * and Roland Bürgmann b ( a* National Geophysical Research Institute (CSIR), Hyderabad, India., b Department of Earth and Planetary Science, University of California, Berkeley, USA.) The Bhuj earthquake of January 26, 2001 in Kachchh, India is the largest event (Mw=7.6) in the last 50 years in a continental shield region. We use GPS, gravity and InSAR measurements and models of postseismic deformation caused by the Bhuj earthquake to assess the viscous strength of the lower crust and upper mantle. To fit the observed displacements we model the relaxation response of a layered viscoelastic earth to the earthquake and determine optimal values for the thickness of an elastic plate and the viscosity of an underlying viscoelastic half-space. The best-fit elastic layer thickness is ~ 34 km, which is close to the local crustal thickness. We find an upper mantle effective viscosity increasing from 3 x Pa s based on deformation in the first 6 months to 2 x Pa s considering data spanning 6 years after the mainshock. The presence of relatively weak lithospheric mantle in western India is consistent with results from independent seismological and petrological studies that show reduced seismic velocities in the top 250 km and early Cenozoic emplacement of magma plutons, indicating an January, 2011 abnormally hot upper mantle beneath the easternmost extent of Kachchh rift basin. The GPS data do not require a viscous lower crust but constrain a lower bound viscosity of Pa s indicating a strong lower crust. Using our best fit upper mantle and lower crust viscosities, we find that the postseismic contribution of viscoelastic relaxation to present day horizontal GPS velocities are small; d ~3 mm/yr. S12_C1 SAR Interferometry detects post-seismic ground deformations related with 2001 Bhuj Earthquake. Arun K. Saraf ( J. D. Das*, Ankita Biswas, Vineeta Rawat, Kanika Sharma & Yazdana Suzat (Department of Earth Sciences, Indian Institute of Technology Roorkee, ROORKEE , INDIA. *Department of Earthquake Engineering, Indian Institute of Technology Roorkee, ROORKEE , INDIA). The ground deformations in the Bhuj earthquake affected region have been analyzed using two InSAR data pairs ( and years) covering an area east of Bhuj constituting a near flat terrain north of Kutch Mainland Fault. Resulting interferograms displaying well formed fringes enabled to draw interesting observational inferences towards the ground deformation of the study area. The analysis of interferogram of the year suggests upliftment of about 8 cm (surface motion towards the satellite) around Kunjisar village and also 91

122 upliftment of 25 cm and 5 cm in the other two areas north of Kunjisar. Whereas, the interferogram image belonging to the year reveals subsidence of about 17 cm (surface motion away from the satellite) in Kunjisar area along with subsidence of about 28 cm and 5 cm in the two areas north and northwest of Kunjisar respectively. Hence, between the years 2003 and 2005 two different episodes of upliftment and subsidence have been observed in the study area. The ground upliftment during probably indicates last phase of ground deformation followed by the onset of subsidence during as the rock volume involved in stress-strain processes began to experience relaxation phase. Keywords: InSAR, Bhuj Earthquake, Deformation, Interferogram S12_C2 Ten decades of GPS observations after2001 Bhuj Earthquake: Possible postseismic mechanisms and processes. C.D. Reddy 1, P.S. Sunil 1, Roland Bürgmann 2, D.V. Chandrashekar 3, Teruyuki Kato 4 ( 1 Indian Institute of Geomagnetism, New Panvel, Navi mumbai, India. 2 Dept of Earth and Planetary Sciences, University of California, Berkely, USA. 3 National Geophysical Research Institute, Hyderabad, India. 4. Earthquake Research Institute, The University of Tokyo, Japan) Earthquakes cause static stress perturbation in the environing crust. Obeying rheological laws, this stress relaxes in a time frame of months to years with spatial extent of few km to hundreds of km. While post-seismic relaxation associated with major interplate earthquakes is irrefutable, it is rather difficult with intraplate earthquakes. The Mw 7.6 Bhuj earthquake on January 26, 2001 in Western India considered to be an intraplate event and provides a unique opportunity to examine post-earthquake relaxation processes far from plate boundaries. To study the characteristics of transient post-seismic deformation, six GPS campaigns were made at 14 sites. The GPS dada have been analyzed to generate time series of the position co-ordinates in east-west (EW), north-south (NS) and up-down (UD) components. The postseismic transients were delineated after removing the inter-seismic and plate motions from these time series. Post-seismic deformation has been observed at all the sites in the study area. During , the site closest to the epicenter exhibited postseismic deformation of about 30 mm and 25 mm in north and east components respectively. More than 90% relaxation seems taken place in first one year after the earthquake. Both NS and EW components of the post-seismic transients can fit well to logarithmic and exponential functions. Close to epicenter, the logarithmic function fits well to initial duration, and exponential function fits well to later duration. All the sites in epicentral region exhibited significant stress relaxation in both east-west and north-south components. The remaining sites (falling east and west of epicentral region) exhibited significantly diminished north-south relaxation. The pattern of postseismic transients supports the hypothesis that the Bhuj region is highly heterogeneous with blocked structures. This region also spatially coincides with the aftershocks distribution following the Bhuj earthquake, with better correlation particularly with those after shocks with more than 10 km depth. Rapidly decaying afterslip and poroelastic mechanisms seem to be responsible for postseismic relaxation in the vicinity of epicenter during the initial period subsequent to the Bhuj earthquake. Postseismic relaxation by viscoelastic mechanism seems to be operative almost in entire Bhuj region. Key words: GPS, postseismic deformation transients, stress relaxation S12_C3 Studies on Seismic Behaviour and associated Topographic Changes in NE India based on Remote Sensing data. R. K. Sukhtankar*( Umamaheswari A*, P. Pradeep Kumar*, T. J. Majumdar** and K. M. Sreejith*** (* Department of Atmospheric and Space Sciences, Pune University, Pune. ** Institute of Seismological Research, Gandhinagar. *** Space Applications Centre, Ahmedabad) Convergence of the Indo-Australian Plates has resulted in the tectonically and seismically active Himalayan Mountain Chain, of which the North-East India forms the easternmost extremity. The NE Indian region however constitutes the syntaxis of the convergence belt and therefore is relatively seismically more active. Seismological data from USGS, ISC and IMD for the period from January, 2011

123 2008 have been collected. Spatio-temporal plots of epicentres have been made decadalwise, which reveal the preferred distribution of epicentres, indicating the planes of weakness through which the crustal stresses get released. These planes of weakness are evidenced by the structural/tectonic fabric, in the form of lineaments, faults and thrusts. Remote sensing data in the form of IRS- 1A, 1C and 1D satellite imageries, have been examined over the same region for the years It revealed characteristic changes in the flow pattern of the streams that originate at the base of the mountain front, sudden deposition/removal of sediments. Such an observation has been ascribed to spatio-temporal trend of release of stresses. These studies reveal the close correlation between epicentral distribution and changes in topography through time. It is, therefore, summarized that analysis of the remote sensing data coupled with the spatiotemporal distribution of epicenters that yield signatures by way of topographic changes, may reveal the probable area of impending major earthquake. It is further suggested that such studies, if applied to the Bhuj region, which is a characteristic of rift tectonics, may help to decipher the probable areas where the crustal stresses are getting accumulated and therefore the future seismically active zone. S12_C4 Crustal deformation mapping in Kachchh, India using InSAR and GPS: Initial results. K. M. Sreejith 1* ( Phone: ), T. J. Majumdar 2, B. K. Rastogi 2, R. Dumka 2, P. Choudhury 2 and F. Bhattacharya 2 ( 1 Geosciences Division, Marine, Geo and Planetary Sciences Group, EPSA, Space Applications Centre (ISRO), Ahmedabad , India. 2 Institute of Seismological Research, Gandhinagar , India.) Kachchh rift basin in Gujarat has been seismically active since the historical period. The devastating Bhuj earthquake of 26 th January 2001 is considered as one of largest intraplate events. After a period of quiescence, since 2006 the area became active with several earthquakes of magnitude >5 and numerous low magnitude events. These are attributed to postseismic relaxation of the region. We made an attempt to study the seismic deformation using differential interferometry (DInSAR) aided with Corner Reflectors and DGPS observations. We have generated and analysed ENVISAT ASAR interferogram with DGPS results of 3 permanent and 11 campaign stations in Kachchh during June 2008 and October The signals related to the deformation are not directly visible in the interferogram due to decorrelation effects. Hence, only areas with coherence > 0.25 were considered for the analysis. A differential interferogram was generated by removing the topographic phases which was later converted to displacement. The deformation map thus generated shows displacement of 0-50 mm along the line of sight of the satellite. DGPS data for a period of show very low deformation rates of about 1-3 mm/yr in the horizontal direction whereas the vertical component of deformation is as high as 13 mm/yr. The vertical deformation from GPS projected along the line of sight of the satellite has given comparable results with InSAR deformation. The deformation map generated in the current study is limited to few areas where coherence is high. Nevertheless, the present study reveals that InSAR can be an effective tool for understanding the crustal deformation in Kachchh due to its wider spatial coverage. We speculate that the inferred deformation rate may be resolved for the Kachchh basin by analysing more SAR data at regular time intervals. However, the currently operating SAR sensors like ENVISAT ASAR, ALOS PALSAR have very limited data availability over India. S12_C5 The Tehri Dam, Uttarakhand: Crustal Strain and Implications in case of Reservoir Induced Loading Swapnamita C. Vaideswaran ( Ajay Paul (Wadia Institute of Himalayan Geology, Dehradun) The Tehri Dam Project is a prestigious and costly irrigation and hydropower project. The m high dam is built downstream from the Bhagirathi and Bhilangana River confluence in the state of Uttarakhand, India. Concerns about the safety of the dam in the event of an earthquake had been raised following the Uttarkashi and Chamoli earthquakes. Despite all measures taken for the dam design safety, two apprehensions regarding, first, how will the dam January,

124 perform in case of an earthquake?, and second, will the loading of dam with a full reservoir level of 830 m and live storage of 2615 million m 3 induce an earthquake? The study of accumulation of strain in the near vicinity of the dam is therefore much required. Using interferometric synthetic aperture radar (InSAR) the region around the reservoir has been studied prior to the filling of the reservoir so as to know the already prevalent stress-strain scenario around the reservoir. The study was done using ENVISAR-ASAR satellite data. This initial study was conducted to understand the nature of changes in different time frames, one month, six months and one year prior to the complete reservoir filling. The disadvantages of the Himalayan topography and rugged nature had to be dealt with. Further, vegetation, atmospheric effects also brought about loss of coherence in the image pairs. Different filtering techniques when applied led to a better understanding of the processing of the data as well as the situation of the region around the dam. However, the constraints of the topography and atmospheric artefact remain for the region. The Goldstein filtering technique gave appreciable results in this case. SAR data was processed for the period The data for one month temporal resolution shows the best coherence and the coherence retention for larger temporal resolution is difficult for the terrain. Based on our seismic network around the region, the seismicity of the region was studied. The PGA calculated for eight different stations for the years , after impounding of the dam. The presence of dense seismic network enhances estimation of accurate seismotectonic conditions due to the present scenario. S12_C6 Satellite altimeter derived geoid/gravity and the lithospheric density anomaly along the convergent zone of Sumatra-Andaman: Implications on the cessation of fault rupture up to 14 o N after 26 December 2004 Sumatra- Andaman earthquake Rajesh S. (Geophysics Group, Wadia Insitute of Himalayan Geology, Dehradun), Majumdar T. J (Institute of Seismological Research, Gandhinagar, Gujarat. ) The 26 December 2004 Sumatra-Andaman earthquake (Mw = 9.1 to 9.3) occurred along the convergent plate boundary of the Indo-Australian and Southeastern Eurasian plates. This caused a devastating Tsunami along the rim of eastern Indian Ocean states, although it gave a rare opportunity to understand the dynamics of earthquake rupture along the convergent margins. An intriguing aspect of this gigantic earthquake was the nature of propagation of fault rupture, its aerial extension and the slip rate. Many investigations 1,2,3,5,9 showed that the rupture length was more than 1400 km from the source and propagated along the frontal arc of the Sumatra- Andaman subduction zone. But what caused the cessation of the rupture up to 14 o N, notwithstanding that the region had been known for oblique convergence where the Indian plate subducts beneath the Andaman arc. The slow rupture of the Sumatra earthquake in the Andaman region was also observed 4 as a consequence of subduction of the Ninetyeast Ridge. The observed surface deformational structures as well as the termination of fault rupture are explained in the light of how an isostatically compensating source body, which is a hotspot related under plated basal material of the Ninetyeast Ridge, affected fault propagation, regional stress distribution and the convergence of the Indian plate. We used the instantaneous sea surface height measured by various satellite altimeter missions such as ERS-1&2, GEOSAT and TOPEX to derive the marine geoid/gravity 6,7 over the whole eastern Indian Ocean. The isostatic compensation mechanism of the Ninetyeast Ridge, where it impinges the Andaman trench (between 7 o to 18 o N) have been studied through geoid to topography, gravity to topography and the continuation of gravity anomalies. Particularly, Geoid to topography ratio could effectively explain the compensations caused by long wavelength lithospheric mantle density anomalies. Moreover, its anomaly wavelength is sensitive to the deeper viscous flow and hence easy to deduce the dynamics of density gradient flow existing between the Ridge compensating body and the Andaman convergent zone. Our results (Rajesh and Majumdar, 2010) obtained from geoid to topography ratio suggest that the compensation depth of the Ninetyeast ridge vary from 13 to 28 km at where it impinges the rupture terminated Andaman trench. While at its northernmost region lower average compensation depth of 8.7 ± 0.4 km is observed. Gravity to topography kernel and the January, 2011

125 upward continued anomaly show relatively dense and viscous hotspot affected under plated basal material as a prominent compensating body. The presence of such an under plated basal material beneath the ridge juxtapose to the Andaman collision zone had affected the regional lithospheric density gradient and hence the crustal rheology. Thus it is evident that in the ridge trench collision zone from 7 o N to 14 o N there exist a strong density gradient driven viscous flow in the lithospheric mantle between ridge compensating body and the subducted lithospheric slab. Such a density barrier can cause rapid dissipation of seismic energy and hence could arrest the propagation of fault further north from 14 o N. References: 1. Ammon et al., 2005, Science, 308, p Banerjee et al., 2005, Science, 308, p Gahalaut et al., 2006, Earth Planet. Sci. Lett, 242, p Gahalaut et al., 2010, Geophys. J. Inter., 180, p Lay et al., 2005, Science, 308, p Majumdar et al., 1998, Int. J. Rem. Sens. 19, p Rajesh et al., 2004, Int. J. Rem. Sens., 25, p Rajesh et al., 2010, Mar. Geophys. Res., DOI /s Shapiro et al., 2008, Geophys. Res. Lett., 35, doi: /2008gl S12_P1 Post-seismic deformation associated with the 2001 Bhuj Earthquake Pallabee Choudhury 1 ( J K Catherine 2, Rakesh Dumka 1, Sumer Chopra 1, V K Gahalaut 2 and B.K. Rastogi 1 ( 1 Institute of Seismological Research, Raisan, Gandhinagar; 2 National Geophysical Research Institute, Hyderabad) Post seismic deformations are going on in Kachchh region, Western India due to relaxation process of the 2001 Bhuj earthquake. For monitoring the crustal deformation in and around Gujarat, Institute of Seismological Research (ISR) has deployed a total of 25 permanent and 11 campaign GPS stations stations starting The velocities of 3 permanent stations and 8 campaign stations run for 3 years show average January, 2011 velocity of 49±1 mm/yr towards NNE with respect to ITRF05 frame which is same as expected from plate tectonics. To estimate local deformation in this region, the Indian plate motion was subtracted from these measurements, taking ISR permanent station (ISRG) as reference. All sites show very small movement of the order of 2-5 mm/yr. The station Lilpar (LLPR) in Wagad area exhibits a velocity of about 4 mm/yr towards SE. It appears that the Wagad area may be moving towards east. Station Dudhai (DUDH) and Chandrani (CHAN) situated on hanging wall side of the 2001 rupture plane, shows northward movement conforming to the main earthquake rupture. Stations on hanging wall side indicate movement towards WSW conforming to the main-earthquake rupture. Displacements of two ISR campaign stations, namely Dudhai (DUDH) and Amrapar (GIBF) for the period 2006 onwards are computed. DUDH is close to DHAM station of IIG while GIBF is close to RATN. The IIG stations were run for the period The reference station is Gandhinagar (ISRG) for ISR and Ahmedabad (AHMD) for IIG. Hence it is possible to combine two data sets and infer the movement at these places from 2001 onwards. The rate of movement towards NW was fast at Dudhai which is close to the epicenter. It exponentially reduced being 12, 6, 4 and 3 mm for four consecutive 6 months periods of and between 2-3 mm/ yr at present. At Amrapar, 50 km north of 2001 epicenter, the rate of movement was 1/3 rd and decaying exponentially. It has been observed that the aftershocks (Md 5) in the source region of the 2001 Bhuj earthquake in the Kachchh region are continuing and the seismicity has expanded up to 60km NE of the 2001 Bhuj earthquake aftershock zone in the last 9 years. The shear deformation for adjustment process in Bhuj earthquake zone is negligible being 2-3 mm/yr as derived from horizontal displacement of GPS stations. However, the rate of vertical displacement estimated from the campaign GPS sites is exceptionally large. Maximum rate of displacement is ~13mm/yr. The vertical movement and / or viscoelastic relaxation at lower depth levels appears to be the probable mechanism for long distance and delayed triggering of the aftershocks. 95

126 S13: Exploration for Oil and Crustal Structure Convener: S.K.Biswas THEME Most of the oil provinces are in the areas of complex geological structure and tectonically active regions with repeated earthquakes such as, Northeastern India Upper Assam, Arunachal, Tripura, & Andaman arc; Northwestern India & Pakistan Rajasthan, Sind, Punjab & Baluchistan; Western and Central India Kutch, Cambay & Narmada which are the active area for SCR earthquakes. Detailed structural studies carried out for oil exploration provide new data and perspective in the thermo-tectonic aspect of these earthquake prone areas. This may provide new insight in the crustal structure and tectonic history and help understanding the neotectonic activity and the ongoing seismicity. With this in view, papers are invited on structure and tectonics and tectono-sedimentary evolution of the petroliferous basins in the regions mentioned above, for presentation and discussion in this session. S13_I1 On-land Kutch basin and its basement configuration from seismic refraction studies and modeling of first arrival travel time skips along Jakhau-Mandvi-Mundra-Adesar profiles B. Rajendra Prasad and Emeritus Scientist (National Geophysical Research Institute, Uppal Road, Hyderabad , India) The Kutch basin is one of the three (Narmada, Cambay and Kutch) major marginal rift basins that are close to each other in western part of the Indian subcontinent. The seismic refraction and wide-angle reflection data were acquired and a first order velocity structure of the Kutch sedimentary basin along four profiles viz. Jakhau-Mandvi, Mandvi- Mundra, Mundra-Adesar and Hamirpur-Halvad is derived. Travel time skip phenomenon has been noticed in the plots of record sections indicating presence of low velocity sediments. The 2-D velocitydepth models derived from these data sets revealed a Mesozoic sedimentary sequence sandwiched between Trap and Limestone layers, in some of the profiles. Two thick low velocity layers (that corresponds early to late Mesozoic era) have been identified. These are dipping towards Mandvi along Jakhau-Mandvi profile. The early Mesozoic layer that is thinning towards southeast is completely missing in Mandvi-Mundra profile. It is also noticed that the early Mesozoic Bhuj formation exists in the northern parts of the Mundra-Adesar and Hamirpur- Halvad profiles, where it directly overlies the granitic basement. The derived velocity-depth model suggests that the basement is about 3 km deep near Jakhau and reaches a depth of about 6 km near Mandvi. The layered structure may correspond to the Tertiary, Trap, Late Mesozoic sediments and Mesozoic limestone. The velocity-depth model obtained in Kutch is very similar to earlier derived model for Jamnagar and Dwarka sub-basins of northwestern Saurashtra peninsula suggesting probable continuity/ linkage between southern on land Kutch and, across the Gulf of Kutch to Saurashtra peninunsula. It is proposed that the evolution of Kutch basin, as a pericratonic rift basin, is essentially controlled by the four (F1-F4) faults inferred from obvious abrupt changes in layer thickness/ velocity along the seismic refraction profiles. Key Words: Marginal Rift, Mesozoic sediments, Low Velocity Layer (LVL), Wide Angle Reflection, Skip phenomenon. S13_I2 Integration of geophysical data for exploration of hydrocarbons - GIS application T. Harinarayana, C. Manoj and R.S. Sastry (National Geophysical Research Institute, Uppal Road, Hyderabad , India) Geographical Information System (GIS) is an effective tool in integrating geo-scientific data sets. A pilot project was taken up to integrate the different geophysical data generated for Hydrocarbon exploration over Kutch region, India. A base-map was prepared from geographical information January, 2011

127 obtained from various sources as well as including the surface topography. Tectonic map available for the region was digitized on a regional scale. The following geophysical datasets obtained over Kutch region were incorporated into the GIS data base. 1) magnetotelluric (point) 2) residual gravity anomaly (point) 3) aeromagnetic (image). Magnetotelluric data sets contain the station location, the geo-electric model for the site as well as a directional parameter called induction vector. The depths to various horizons were smoothed by Kriging and thickness maps of various geological units of the region such as Basalt, Sediment and basement depth were obtained. A great deal of new insights into the results of MT is possible, when a joint analysis of different geophysical data sets is carried out. Gravity information, overlaid on MT results clearly show the uplifted basement in central Kutch. To delineate further anomalous regions, aeromagnetic map obtained over Kutch also was overlaid on the other geophysical data sets. MT induction vectors points to conductive regions within Earth. Induction vectors overlaid over gravity and magnetic anomalies yielded interesting results and gave new information on the subsurface geology and tectonics of the region. Interrelationship of these geophysical data obtained by raster calculations, the sub-surface structure parameters and their implication on the hydrocarbon potential bearing sediments are discussed. S13_I3 Impact of tectonics, sedimentation processes and evolving trap styles in Andaman island arc. Sandip K Roy (Department of Earth Sciences, IIT, Bombay. Following the breakup of Gondwanaland, the northward flight of the Indian plate, its anticlockwise rotation, impingement beneath the Eurasian plate and incipient sedimentation of oceanic crust derived sediments initiated development of Andaman island arc. Upper Cretaceous to recent marine sedimentation impacted by five major benchmarks in associated processes of plate convergence evolved the Andaman island arc as we see today. The first benchmark is the Oblique subduction of the Indian plate beneath the Eurasian plate in Late Cretaceous and scrapping of oceanic crust in early sedimentation processes in Upper Cretaceous-Early January, 2011 Paleogene time and acidic volcanism at the upper part of Eocene time. Late Cretaceous sedimentation is marked by Radiolarian cherts, Jaspers, globigerinid limestones involving deep water sedimentation. Exotic trap derived poorly sorted coarse clastics with abundant clasts of acidic igneous rock fragments, mudstones and subordinate coal, attributed to debris flows with and Carbonaceous pyritic shale defines the Eocene sedimentation. In Late Oligocene, Change in plate movement direction along with hiatus, renewed acceleration in subduction, flysch deposition and upliftment of the Andaman islands comprised the late palaeogene development in basin evolution is the next benchmark. The flysch is a sand rich system with thin sand shale intercalations intervening thick clast and concretion filled coarse to fine, amalgamated sandstone beds, noted particularly in the forearc and the subduction zones. N-S trending dextral wrenches, parallel to the plate boundary played a significant role in shift of arc positions. The implications are the role of these dextral shears in shifting coarse sediments to far off positions from the provenance during the Paleogene time.. Early Miocene compression in subduction zone and forearc, extensional tectonics in backarc reflected by pull apart basin formation and active acidic episodic volcanism from the volcanic arc marked the third stage in evolution of the island arc. It is a Carbonate rich section with foraminiferal limestones and finer clastics. NW-SE and NE-SW conjugate shears, very active in Neogene times acted as triggers in generation of structures in Subduction zone-forearc regime. NE-SW pull apart systems in the back arc due to extension along with rise of volcanic arc expressions and sea rises dominated the Neogene growth in back arc and volcanic arc. Renewed Mid Miocene compression near plate boundary, outgrowth of accretionary prism with contribution of Bengal fan, active conjugate wrench system oblique to Andaman trench and carbonate sedimentation overprinted the arc in the next stage of evolution.. Late Miocene to recent time witnessed true sea floor spreading in the backarc., pyroclastic flows in Ritchies Archipelago, emergence of volcanic sea rises Alcock and Sewell, and emergence of Ritchies 97

128 Archipelago and some islands in Nicobar with dominant Carbonate sedimentation imprinted the latest bench mark in evolution. The NW-SE wrenches were active in creation of tight anticlines in the forearc. Each tectonic element in the arc system defined its own trap style. Piggyback basins and folded accretionary thrust packets with associated sedimentation affected by gravity flows and turbidity currents, axial turbidites along the trench zone, and accretion of sediments in the accretionary prism. While accretionary thrust packets symbolized the Cretaceous section in a position of present day forearc, successively the thrust packets encompassed younger sedimentary packages from east to west implying a migratory type of arc trench system shifting westwards. The forearc is marked by large tight enechelon anticlines, thrust related structures, pinchouts and wedgeouts against the volcanic arc carbonates in Neogene time. BSR,S indicating gas hydrates along with bright spots,flat spots and gas chimneys of seismic controls are also conspicuous in the Neogene section. In Neogene, the intra volcanic basins along with structures associated with pull apart basin formation in the backarc define the structural features away from the Andaman trench in Lower Miocene time. Fault closures on the flanks of pull apart basins ( half grabens) in Oligocene, fluvial channels ( Oligocene), carbonate buildup on highs in early Miocene and Pre rift structural traps in the volcanic arc and the backarc.. In the entire evolutionary process, some fundamental questions still remain to be defined, like the provenance of deep marine debris flow affected early paleogene sedimentation, flysch deposition in Oligocene and deep water carbonate deposition in Neogene, role of dextral N-S strike slip faults in sedimentation with depo centre shifts, pulses of volcanism linked to the entire evolutionary process and lack of seismic imaging in paleogene and older sections. Linkage of overriding controls of tectonics to sedimentation is likely to result in better understanding of temporal and spatial facies distribution in relation to trap presence and style in the Island arc. S13_C1 Geophysical Investigations of the Gulf of Kachchh, Northwest India. D. Gopala Rao and N. Mahendar (Geology Department, Osmania University, Hyderabad, India.) The gulf of Kachchh of the northwest India is the longest east-west trending gulf along the Indian coasts. The tide dominated (5 to 6 m high) gulf is ~75 km wide and ~125 km long separating the Kutch sedimentary onshore basin from the Saurashtra peninsula in the south. The Kutch main land basin crust consists of thin Tertiary sediments (including coastal alluvium), thick Deccan volcanic rocks and Mesozoic sediments overlying the Precambrian crust. The rifted and half graben basin structure is known extending offshore especially with increase in thickness of sedimentary sequences. Our recent studies have revealed that the gulf morphology is dominated by thick alluvial mud-flats of the northern coast excepting rocky promontories of the northwest coast and corals rocks (live and relict) of the southwest coast. In view of the hydrocarbon prospectus of the Mesozoic sediments of the Kutch sedimentary basin and its offshore extents, several geophysical investigations includes high resolution seismic reflection, single and multi-channel deep seismic reflection and refraction (Ocean Bottom Seismometer), magneto-telluric, satellite derived free-air gravity, magnetic and bathymetry investigations have been undertaken. The high resolution seismic reflection studies had revealed upper Quaternary sediments seismic sequences of the limestone and coral sands and relict coral remnants and their deposition pattern affected by the sea level change of the last 100 Kyrs and neo-tectonics. The 2-D crust model studies of the gravity and magnetic anomalies lead to infer presence of 1 to 2 km thick volcanic at 0.8 to 1.0 km depth overlying the thick low density Mesozoic sediments. It is worth integration of the results of the deep-seismic reflection and refraction, magneto-telluric, gravity and magnetic anomalies and to shed light further on the basin crust structure especially thicknesses of the volcanic and Mesozoic rocks overlying the Precambrian granitic crust and their geophysical characters. It shall enable more details of structural elements affecting the rifted-half graben extent and its termination i.e. whether the rift graben abuts against major fault (east-west trending North Kathiawar Fault)? and the offshore extents of the January, 2011

129 onshore near north-south extending Median High. Plus nature of the faults, basin configuration and tectonics shall help in constraining gulf origin and it s possible relation to the separation of India from eastern Gondwana Land during late Cretaceous. S13_C2 2D-Geoelectric Subsurface structure in the surroundings of the Epicenter Zone of 2001, Bhuj Earthquake Using Magnetotelluric Studies. Kapil Mohan 1, R. S. Sastry 2, T. Harinarayana 3 and B.K. Rastogi 1 ( 1 Institute of Seismological Research, Raisan, Gandhinagar , Gujarat, India., 2 Sreemitra cute, Nagarjuna Nagar, Tarnaka, Secundrabad , India., 3 National Geophysical Research institute, Hyderabad , India.) Hundreds of aftershocks having magnitude Me 3 of 2001 Bhuj earthquake of Mw7.7 have been recorded by various agencies like National Geophysical Research institute (NGRI) and Institute of Seismological Research (ISR). Until 2006, the seismicity was very high and the earthquakes of M w >5 were recorded in the epicenter region. After 2006, aftershocks of Bhuj earthquake and seismic activity are concentrating in the eastern part of the epicentral zone along Samkhiali basin and Wagad area. To decipher the nature of the faults in this area, two Magnetotelluric (MT) profiles each of length 15km have been acquired with an inter station spacing of 1 to 3 km. The profiles have been taken about 25km west and east to the epicenter of 2001 Bhuj earthquake ( o N, o E) in N-S to NE-SW direction. From the 1D Bostick analysis of the eastern profile of 11 MT stations, the sedimentary thickness is found to be varying from 1.5 km to 2.3 km whereas along the western profile of 8MT stations, the sedimentary thickness is found to be varying from 400 m to 1.7 km. The 2D inversion analysis of MT data of the eastern profile shows two distinctive resistive blocks corresponding to Wagad uplift in the north and the Kachchh Mainland in the south. The KMF is seen west of Bhachau. Further east the geologists believe its extension beneath the soil. In this study, the assumed eastern extension of KMF is not found. However, a hidden fault is found 4 km north to the assumed extension of KMF. At same location in the western profile indications of the fault are also seen which supports this result. The possibility of further extension of January, 2011 South Wagad Fault in the west is also seen along the western profile at 14km north of KMF by virtue of basement variation of half kilometer. S13_P1 Passive Seismic Imaging of Petroleum Reservoir Mr. Sunjay (Ph. D. Research Scholar, Department of Geophysics, BHU, Varanasi , India) Low-Frequency seismic waves give geophysicists a new seismic imaging technique to monitor sweet spots, wealth and health of reservoir. Wavelet transform, known as a mathematical microscope, has scope to copeup with non stationary signal to delve deep into geophysical seismic signal processing and interpretation for hydrocarbon exploration and production. Hydrocarbon reservoirs can be the origin of a continuous source of low-frequency seismic waves. These phenomena are sometimes called hydrocarbon microtremors. Low frequency (LF) passive seismic is a breakthrough Direct Hydrocarbon Indicator (DHI) technology for identifying and delineating oil and gas reservoirs by analyzing the spectral attributes of naturally occurring, low frequency seismic wavefields. One such technology is low-frequency (LF) passive seismic technology, which is helping to improve the value of conventional seismic data by overlaying structural interpretations with reservoir information. The existence of coherent patterns relating to oil and gas reservoirs in the low frequency domain has been established in many parts of the world. Two mechanisms that can generate (DHI) in the background spectrum are of special interest: resonant amplification and resonant scattering. Resonant amplification effects of ambient seismic waves are likely candidates for hydrocarbon micro-scale tremor signals. Resonant amplification effects behave like a secondary source within the reservoir. Resonant scattering occurs on a macro-scale, where characteristic maxima are generated by reflections, both between the reservoir and the surface and within the reservoir, caused by complex impedance contrast due to the reservoir. A wavelet transform is employed for the joint time frequency analysis of seismic data. The wavelet transform properties such as localization, which is essential for the analysis of transient signals, provide a filter to extract characteristics of interest such as energy and predominant time scales. The orthonormal 99

130 decomposition of the signal energy estimated by the wavelet variance into the retained scales provides a useful means of describing the change in the signal magnitude associated with the triggering events. This type of analysis discriminates between signal phase arrival and spurious signal triggering by the different magnitude of local relative energy, which is much smaller in the latter case. S13_P2 Identification of Shallow Geological features in the Wagad area (Kachchh) using 2D Electrical Survey Kapil Mohan, Girish Patel, Gagan Bhatia, Sunita Devi and B.K. Rastogi (Institute of Seismological Research, Raisan, Gandhinagar , Gujarat (India)) The Wagad area is very close to the epicenter of 2001 Bhuj earthquake. Large number of aftershocks was recorded in the area. Since 2005, the seismicity is shifted to wagad area towards east (ISR annual report, ). The South Wagad Fault (SWF) is the Major Fault in this region. A topographical variations of almost 10m in the N-S direction is found from the SRTM (Shuttle Radar Topography Mission) data in the area at Mae dome near Vamka village (23.43 o N, o E, 17km east of the epicenter of 2001 Bhuj mainshock (2001 Bhuj Eq.)) and Shivlakha village (23.40 o N, o E, 36km east of 2001 Bhuj Eq.). Hence SWF is inferred to be passing in the near vicinity. However, for the purpose of deciding the most preferred site of trenching for paleoseismological study, the exact location of the fault surface has to be found. Therefore, four electrical profiles having length of 150 to 220 m have been acquired along N-S direction using Syscal Pro (switch 72) instrument to locate the exact position of the SWF in the region. Profile-I at Vamka village (Mae dome), Profile-II at Halra village (23.40 o N, o E, 23km east of 2001 Bhuj Eq., Profile-III at Adhoi village (23.40 o N, o E, 25.5km east of 2001 Bhuj Eq. and Profile-IV at Shivlakha village The resistivity data has been inverted using Res2dinv program by least square inversion technique shows two conductive fracture zones in the Profile-I at 78m and 110m south of the starting point of the profile. The first conductive fracture zone is identified as the boundary of the Mesozoic and Tertiary rocks. The second conductive zone is dipping steeply towards south and is also seen in profile IV and may correspond to South Wagad Fault. S13_P3 2D electrical imaging survey to identify the shallow subsurface layer in the Gujarat International Finance- Tech (GIFT) City area of Gandhinagar Kapil Mohan, Gagan Bhatia, Girish Patel and B.K. Rastogi (Institute of Seismological Research, Raisan, Gandhinagar , Gujarat (India) The GIFT city is planned near the capital city, Gandhinagar, on the left bank of the River Sabarmati across Intitute of seismological Research (ISR), at a distance of around 12 km from Ahmedabad and 8 km from Gandhinagar. The 500 acre city will accommodate a resident population of 50 thousand and a floating population of 5.5 lakhs and act as a central business district. Looking the economic importance of the area, the seismic hazard assessment of this region has been assigned to Institute of Seismological Research by Gujarat State Government. The shallow subsurface geological layers play a vital role in the estimation of seismic hazard in an area. Therefore 2D resistivity survey (shallow) has been conducted using Syscal-Pro (Switch72) instrument at 23 o N 72 o E in the area to identify the subsurface shallow layers. The profile was in N 109 o E direction with a length of 497m and with initial electrode spacing of 7m. The resistivity data has been acquired using Schlumberger and Wenner electrode configurations. The Electre II software has been used to create the electrode sequence and Prosys II software for data downloading and processing. The data has been finally inverted through RES2DINV software provided by IRIS. The least square Inversion technique has been used to invert the resistivity data. The 2D shallow resistivity pseudo sections thus prepared using both electrode configurations depict resistivity contrast (layers) at a depth of 6.5 and 12m, 15m and 35m and 45m. The profile taken from E to W, shows higher values towards west. The major layers are found at 17 and 36m. This information is used for identification of water table and soil strength January, 2011

131 S14: Ground Response Studies for Nuclear Power Plants Convener : A.G. Chhatre THEME Nuclear Power Plants are designed for Site Specific Earthquake Ground Motion (SSGM). In a nuclear power plant, not only the civil structures but mechanical, electrical, control and instrumentation equipment for safety systems and safety support systems are designed for Safe Shutdown Earthquake (SSE). The work involves carrying out geological field check and seismological studies to arrive at the active faults within an area of 300 Km radius around the plant site, to arrive at the maximum magnitude earthquake potential of these active faults to arrive at Site Specific Earthquake Ground Motion (SSGM) Subsequent to that the civil structures and also the mechanical equipment viz. Pumps, Valves, Heat Exchangers, Tanks, Vessels, Piping System, Ducting; Electrical Equipment viz. transformers, diesel generators, cable trays, low voltage & medium voltage switch gears, battery chargers, electrical panels, battery banks and delicate instruments viz., relay, contactors, push buttons, thermowells, pressure gauges, switches are seismically qualified by a combination of analysis and shake table tests to demonstrate structural integrity, pressure boundary integrity & functional performance of active components/devices. Huge amount of technical data has been collected all over the world regarding good and poor performance of Civil structures, Mechanical Electrical and Instrumentation & Control Systems which have witnessed large number of earthquakes close to the conventional industries and Nuclear Power Plants viz., Koyna (1967) & Bhuj (2001) in India which affected petrochemical, thermal & hydro power plants, cement & general industry, Kobe (1995) in Japan which affected generally industries, Niigataken Chuetsu Oki (2007) in Japan which affected Kashivazaki-Kariwa Nuclear Power Plants, Noto Hantou (2007) in Japan which affected Shika Nuclear Power Plant, Chi-Chi (1999) in Taiwan which affected general industries, San Fernando (1971) earthquake in USA which affected El Centro Steam Plant, Coalinga (1983) earthquake in USA which affected Pleasant Valley Pumping Plant and oil field facilities, Imperial Valley (1979) earthquake in USA which affected Sylmar Converter Station and the Rinaldi Receiving Station etc. There is a technical session on the topic of ground motion studies for structures, systems and equipment of Nuclear Power Plants and also on the earthquake resistance design of Industrial structures, residential buildings, and bridges. Institutes, Research laboratories & Consultants are involved in the activities of seismic design of residential buildings to a great extent and also in the design of bridges, industrial structures and Nuclear Power Plants across the country. Papers are invited in this special session of ground response studies for structures, systems and equipment of Nuclear Power Plants, Industrial & residential civil structures and Bridges. The topics can be on Attenuation correlations for active and stable continental region Geological and seismological studies, Earthquake ground motion by deterministic and probabilistic method, Design of structures systems and equipment for Nuclear Power Plants Structural design of Industrial and residential civil structures, bridges Performance of the above structures, systems and equipment during the earthquake Geological studies around nuclear power plants to arrive at the earthquake ground motion for design of civil, mechanical, electrical and instrumentation of control systems January,

132 S14_I1 Near-Field ground motion simulation for the 26th January 2001 Gujarat earthquake STG Raghukanth and B. Bhanu Teja (Dept. of Civil Engineering, IIT Madras , The 26 th January 2001 Gujarat earthquakes regarded as one of the devastating event in India provides an opportunity to understand the ground motion in SCR. This earthquake demonstrated the vulnerability of Indian habitat with rehabilitation and reconstruction costs at $2.3 billion. The loss of life and damage during for this event is mainly attributed to the collapse of built infrastructure in this region. Indian Meteorology Department reported the epicenter of this quake at N, E. This earthquake also triggered wide-spread liquefaction and ground deformation in the epicentral region. The Gujarat event generated a lot of interest among seismologists and engineers because of similar SCR worldwide and also increased the awareness towards earthquake disaster mitigation in India. Unfortunately no strong motion records are available for this event in the epicentral region. The only way to quantify the ground motion during this earthquake is through analytical approaches. Since the Gujarat earthquake produced many ground motion records at teleseismic distances, finite fault-slip models determined from these data are available. From such models, source parameters such as location of the epicentre, orientation of the fault plane, rupture dimensions, and slip distribution are known. With this limited information, one can use analytical approaches to estimate ground motion in the epicentral region. The software package, SPECFEM3D_GLOBE which is a collection of Fortran subroutines for modeling the global seismic wave propagation is used to compute the displacement time histories in the epicentral region. This package has been implemented on HP Proliant DL160 G5 servers known as Vega supercluster available at IIT Madras. The effect of self-gravitation, lateral variations in material properties, ellipticity, topography and bathymetry, the oceans, rotation have been incorporated in simulating ground motion. The Earth is modelled with million grid points. Displacement time histories are simulated at various stations in the epicentral region. A contour map of permanent ground displacements in the near source region is provided. The obtained results are validated to the extent possible by comparing them with recorded peak ground velocity data and field observations. S14_I2 Displacement-based Design of Structures: a consistent framework of limiting-strain based design method C. V. R. Murty (Department of Civil Engineering, Indian Institute of Technology Madras,Chennai ) Earthquakes impose displacements at the base of structures. This dynamically changing grounddisplacement under structures subject to earthquake shaking then results in imposed relative-deformations at upper elevations of structures, and thereby relative-deformations at ends of individual members of structures. Under strong shaking, the philosophy of earthquake-resistant design expects damage in structural components. The performance of each member can be assessed by its capability to withstand this imposed relative displacement. The current design methods in India for individual structural members are of two types, namely (a) strengthbased method (e.g., Limit State Method as stated in IS ), and (b) partially force-based and partially deformation-based method (e.g., Limit State Method as stated in IS and IS ). These methods cannot help estimate the deformation capacity of a structure; they can neither help estimate the deformation demand on the structure under specified ground deformation. This is because (a) the Indian steel code (IS ) specifies only design limit states of strength for all load actions corresponding to yield and rupture strengths; design limit states are not specified of strains; and (b) the Indian concrete code (IS ) specifies design limit states only of axial and bending strains; for shearing and torsional actions, only design limit states of strength are specified but not the design limit states of strains. Thus, a complete description of the limiting strains is not available for all load actions, namely extensionalcompressional, bending, shearing and twisting actions, to estimate of deformation capacity of both new and existing structures January, 2011

133 The paper proposes a framework for inelastic design of concrete and steel structures (in line with the Indian design codes), which will help in understanding the level of deformation actions at which design strength limits are reached, the level of damage sustained by structures when subject to seismic shaking, and the residual-deformation capacity that can be relied upon in resisting future ground shaking. The framework will present a description of limiting strain states for all load actions; it will caution on possible interactions between these strain effects. The emergence of such a method is expected to lead to a greater reliability of earthquake-resistant design of structures. S14_I3 Seismic Design of Bridges for Displacement Loading Rupen Goswami (Department of Civil Engineering,Indian Institute of Technology Madras) Traditional earthquake-resistant design of bridges is based on equivalent lateral forces estimated as per the codes of practice. There is no provision limiting the lateral deflection of bridges. Further, there is no explicit requirement on the minimum ductility of bridges. All inelasticity, and hence ductility, is expected to be through the nonlinear actions restricted to the substructures. In the current practice, the level of ductility embedded in the substructures is not clearly quantified at the time of design. Prescriptive ductile detailing requirements for building columns are being extrapolated for bridge piers also. Explicit experimental studies are not available within India on the inherent ductility of bridge piers designed as per Indian codes. The expected relative displacement demand on bridge piers is not quantified in the codes of practice for different seismic zones. With both the demand and the supply not estimated, actual behaviour of bridges is unknown, especially under strong seismic shaking. In addition, the problem is pronounced in the nearfield regions (of proximity to seismic faults), where the expected displacement under bridges can be large. Ground displacement observed is significantly different under near-fault motion, and can impose on bridges, large residual or permanent displacement (as in fault normal condition) or large instantaneous or peak ground displacement (as in fault parallel condition). These instantaneous or permanent January, 2011 displacements are to be accommodated in the bridge and its substructure, which must have adequate lateral displacement capacity. This paper highlights issues related to ways of assessing lateral displacement capacity of reinforced concrete bridge piers, and improving the same through choice of section and detailing. S14_I4 Earthquake Experience based performance of civil structures, piping systems, cable trays, ducting and mechanical, electrical, instrumentation & control equipment from industries in India Faisal Dastageer, Anshuman Singh, Rahul Mittal, Santosh Khandwe, B. Santosh, U.P. Singh, S.D. Bhawsar, R.N. Bhawal, S.M. Ingole, and A.G. Chhatre (Nuclear Power Corporation of India Limited, Mumbai) and Rajesh Mishra (Bhabha Atomic Research Center, Mumbai) Nuclear Power plants in India have been designed for earthquake resistance by the methods of analysis & testing. Many of the electrical & instrumentation equipment have been tested on shake tables available in India. The performance of the civil structures, piping systems, cable trays, ducting and mechanical, electrical, instrumentation & control equipment in industries around Koyna (1967, 6.5 M), Bhuj (2001, 7.6 M) & Muzaffarabad (2005, 7.6 M) which have witnessed the earthquake is also available. Contrary to the common perception that Koyna, Bhuj and Muzaffarabad earthquakes were a complete disaster, the data collected on equipment performance from the industries around the area was that the equipment and piping failure due to inertial load were rather nil and wherever the failures were there, they were due to total collapse of the civil structure in which they were installed or falling of brick wall on to the equipment or piping or failure of equipment due to improper or no anchorage of the equipment or due to seismic anchor movement. Apart from the failures of transformers on wheels, battery banks on wooden stillage, false ceiling, lighting fixtures and brick walls the performance of other equipment was good (tanks, pumps, valves, compressors, DGs, fans and blowers, chillers, HVAC ducts, cranes, transformers, switchgears, MCCs, battery chargers and inverters, battery banks, distribution panels, MG sets, cable trays, 103

134 false ceiling, glass partition, lighting fixtures, brick walls, piping system, instrumentation and control panels, instrumentation devices like relays, temperature and pressure sensors, switches, meters etc ) Indian experience on equipment which have witnessed earthquake is from the general industry, although not from the Nuclear Power Plants, viz. thermal & hydro power plants, chemical & fertilizer industry, cement plants, petrochemical plants, electrical substations etc. and is very similar to the experience at Kashiwazaki-Kariwa NPP on soft rock(vs30 200m/sec) and Shika NPP on hard rock(vs m/sec) in Japan. Earthquake experience data from USA, European countries, Russia, Japan etc. as available in the form of Generic Implementation Procedure GIP-DOE, GIP-SQUG, GIP-VVER, FEMA, ASME-QME , IEEE-628 etc. as collected by various institutes e.g. EPRI, EERI, LLNL from USA have also been used. The performance of the equipment during the shake table tests or during the earthquake forms the data base of equipment, which can be used by general industry as well as by nuclear industry for their design and forms the part of the experience based data. S14_I5 Seismic Analysis of a typical Nuclear Power Plant structure Apurba Mondal, Indrajit Ray, Raghupati Roy, D.K.Jain1, U.S.P. Verma (Nuclear Power Corporation of India Ltd., Mumbai, India) The operating experience of Nuclear Power plants with 220 MWe & 540 MWe PHWRs have demonstrated that they are safe, reliable and cost competitive. The next generation Indian 700 MWe PHWR has been designed after modifying the basic features of 540 MWe Indian PHWR. From the conceptual stage of 700 MWe PHWR plant layout as well as structural layout has been developed considering the both constructional aspect as well as improvement in structural performance particularly with respect to seismic loading. The Nuclear Building, which is specially conceived for the Indian 700MWe PHWR projects, consists of reactor building (RB), spent fuel storage bay (SFSB) and the remaining portion housing various reactor auxiliary systems. In order to achieve improved structural performance and bring overall economy in the structural design and to suit faster construction considering the present day advanced construction methodology, a common foundation raft for the reactor building, SFSB, reactor auxiliary building and various service areas has been planned. The structural framing in the Nuclear Building outside RB has been connected to the cylindrical outer containment structure in order to utilize the structural stiffness of the outer containment wall in improving the seismic response of the portion of the NB around RB. Nuclear safety related structures are designed for two levels of earthquakes i.e OBE (operating basis earthquake) & SSE (Safe shutdown earthquake). The detailed 3-D integrated finite element model of the structural system along with the simplified models of the major equipment has been considered. The soil-structure interaction analysis is also carried out with sub-structure approach. Fluid-structure interaction of pool water is also appropriately considered. Detailed methodology has been developed to incorporate the accidental torsion for structural design purpose. S14_C1 Design of Distribution Systems, viz., Piping, Cable Trays and Ducting Faisal Dastageer, Anshuman Singh, Rahul Mittal, Santosh Khandwe, B. Santosh, U.P. Singh, S.M. Ingole, R.N. Bhawal, S.D. Bhawsar* and A.G. Chhatre (NPCIL, Mumbai) Lots of efforts are put up in seismic qualification of piping system by performing time history analysis, response spectrum analysis or multi support excitation analysis to find out the inertial forces and the resultant stresses in the piping component. As done in other parts of the world in the past, the Nuclear Power Plants in India on hard rock have been designed for ground motion of soft rock, since not many records were available from the hard rock sites. The supports for the piping, cable trays and ducting in conventional industries in general were of rod hanger type. The piping and cable trays with rod hangers have frequency less than 1 Hz and should experience an acceleration of about 0.03g, however, the soft rock spectrum used for the design necessitated the piping and cable trays to meet an acceleration of 0.2g instead of 0.03g. As the rod January, 2011

135 hangers could not meet the qualification requirement for these accelerations, the supports were changed to angles and channel sections, thereby increasing their stiffness & frequency, resulting in attracting more acceleration, further, requiring increase in the support section size, till the frequency of the system goes in the descending part of the response spectrum. Now, this process of increased support stiffness is being reverted back to meet the low acceleration in low frequency region of the hard rock ground motion. Large unrealistic conservative floor response spectra are one of the another reasons for conservative rigid supports or snubber on piping. The analytically calculated floor response spectra for Kashiwazaki kariwa(on soft soil) and for Shika (on hard rock ) are higher by about 40% on first floor and by about 100% on second floor than the recorded values. The aim of putting the Seismic instruments in a NPP buildings is to benchmark the analytical calculations so as to remove the areas of un-conservatism lf any, but the aim is also to remove the areas of too much conservatism as well. As brought out above, based on the feed back from the experienced based data, there is a need to re think and correct ourselves in our design methodologies. In case of piping, it observed that there are no failures observed due to inertial loads, rather the failures are due to Seismic anchor movement or due to rigid smaller piping connected to bigger equipment. There is a possibility of failure of piping due to inertial load which may be due to reduction in load carrying capacity of the piping due to thickness reduction because of corrosion which can be tackled by regular in-service-inspection or by replacement, if the thickness goes below allowable value. As observed in Indian experience from general industry and also from Kashiwazaki Kariwa NPP Shika NPP in Japan, piping have survived with both rigid supports as well as with flexible rod support. So it is better to have a flexible piping with rod hangers rather than rigid piping with closed spaced supports with U clamps. Flexible piping can withstand SAM with comfortable margin and will have low thermal stresses. In view of number of similar observations, there is a need to understand, as to, whether there is a need of conducting the time consuming response spectrum analysis of piping system to arrive at the seismic inertial responses which anyway have not caused any failure. There is need of conducting a simplified seismic design of piping system and the supports by tables and charts aided by equivalent static analysis. Similar is the case of cable tray and ducting, in order to not to attract higher accelerations by going in descending part of the response spectrum where the acceleration are lower for the soft soil spectra, the supporting system have been made rigid to increase its stiffnesses. However, based on the experience of the real earthquakes, it is seen that if one make the system flexible, it will result in attracting lesser earthquake accelerations and of light weight. By making the supports rigid, it does not add any safety but makes the whole system uneconomical, so, there is a need to look into the supporting of cable trays and ducts. S14_C2 Earthquake Ground Motion Generation for Nuclear Power Plant Faisal Dastageer, Anshuman Singh, Rahul Mittal, Santosh Khandwe, B. Santosh, U.P. Singh, S.M. Ingole, R.N. Bhawal, S.D. Bhawsar* and A.G. Chhatre (NPCIL, Mumbai) The Nuclear Power Plant (NPP) is designed for two levels of earthquake viz., Operating Basis Earthquake (OBE) (S1) and Safe Shutdown Earthquake (SSE) (S2). The OBE (S1) level ground motion corresponds to the maximum level of ground motion, which can reasonably be experienced at the site once during the operating life of nuclear power plant with a return period of 100 years. Whereas, the SSE (S2) level ground motion corresponds to the maximum earthquake potential of the (site) region with a return period of years. SSE represents the maximum level of ground motion to be used for design of safety related structures, systems and equipment (SS&E) of NPP. For these two levels of earthquake i.e. OBE (S1) & SSE (S2), it is required to specify the Site Specific Ground Motion (SSGM) from which the Design Basis Ground Motions (DBGM) is arrived at. A study of regional geology and seismo tectonic features in the region of 300 km radius from site are required to be conducted to delineate the faults/ lineaments based on the landsat imageries, as given in Seismotectonic Atlas of India and its environs, January,

136 gravity anomaly map and also based on Micro Earthquake (MEQ) and Earthquake data (historical as well as recorded) in the region. The field check study is carried out in three ranges viz., Local (5 Km), Intermediate range (50 km) and Regional (300 km). Based on the field check study, the lineaments are given a status of capable fault and a maximum earthquake potential (in terms of magnitude) and depth of focus are assigned. For determining the ground motion, a SSE (S2) level of earthquake is required to be determined in terms of Maximum earthquake potential (in terms of Magnitude, Depth of focus, and Epicentral distance (Closest distance of the active fault). The ground motion is determined deterministically by three methods viz., first from the recorded time histories from the site or from the sites having similar geological and seismological features, secondly in the areas with low seismicity were recorded time histories are not available one can generate synthetic ground motion for the ground motion parameters viz. stress drop, geometric attenuation, inelastic attenuation and kappa and site amplification, thirdly in the areas of low seismicity one can also use the attenuation correlation developed for the region using the recorded ground motion or the synthetic ground motion. In the time history based method whether actual recorded or synthetic, normalized mean plus one sigma spectral shapes can be determined for controlling level of earthquake The aim of generating the normalized mean plus one sigma spectra for such a range of S2 level of earthquake time histories is to generate a mean plus one standard deviation spectra i.e. to define Dynamic Amplification Factors (DAF) with 84% non exceedance probability at all the frequencies and not only the maximum DAF. The normalized mean plus one sigma spectral shapes can then be anchored to the weighted mean PGA derived using number of correlations suitable for the geology and tectonics of the region for the controlling earthquakes. In case of the attenuation correlation based method, the mean plus one sigma spectra is generated using weightages to the correlation at all the frequencies including the pga for the controlling magnitude & distance level of earthquakes to get the SSGM. The DBGM is obtained from the SSGM by joining the peaks of the SSGM and smoothening. The paper brings out the procedure for conducting field check study, determination of the ground motion by deterministic method and also a case study of field check carried out and generation of ground motion for KAPP-3,4 Nuclear Power Plant site. S14_P1 Estimation of Spectral decay parameter Kappa, Seismic Moment, Stress drop, Source Dimension and Seismic Energy for Small Earthquakes in Kachchh region from Strong Motion Santosh Kumar 1, Dinesh Kumar 2, B.K. Rastogi 1 ( 1 Institute of Seismological Research, Gandhinagar. 2 Department of Geophysics, Kurukshetra University Kurukshetra India) The spectral decay parameter Kappa (k) characterizes the sharp decay at high frequency of acceleration spectra. This sharp decay of seismic energy may be attributed to source effect or combination of near surface attenuation and near surface effect. A set of 108 accelerograms from 25 earthquakes recorded at 15 sites in Kachchh region have been spectrally analyzed to estimate kappa and other source parameters including seismic moment, stress drop and source dimension. The Brune s source model has been used for this purpose. The accelerograms used here have been recorded in the epicentral distance range of km. The kappa values have been found in the range The source radii are found to be between 200m to 900m. The stress drop value is 100 bars for most of the events. It shows Kachchh to be a the high stress regime. The estimated seismic energy ranges from J to J. The source parameters estimated here are useful for understanding the earthquake source model of the region. The kappa values obtained here can be used to simulate strong ground motions from moderate to large earthquakes in the region which in turn is useful for the proper evaluation of seismic hazard in the region. S14_P2 Seismotectonic study to characterize the seismic sources in Gulf of Khambhat and prediction of strong ground motion in the surrounding Saurashtra and Mainland regions of Gujarat (India) January, 2011

137 Sandeep Kumar Aggarwal ( Sumer Chopra, Babita Sharma, B. Sairam, Santosh Kumar, Vishwa Joshi and B.K.Rastogi (Institute of Seismological Research, Gandhinagar ) The widely felt earthquake of M w 3.5 on 02 nd May, 2008 at 27.6km depth in Gulf of Khambhat near Surat was recorded at 33 broadband stations of Gujarat. Two aftershocks of Mw 3.2, 2.7 were recorded within one hour. The seismic data within 80 to 160 km provided an opportunity to study the seismotectonics of the region by determining Centroid Moment Tensor (CMT) solution and source parameters. The CMT solution depicts WSW-ENE tectonic trend coinciding with the trend of Narmada-Tapti rift. The earthquake may be generated by a localized earthquake source on the segmented fault extending in WSW-ENE direction. The Narmada-Son rift has a capacity to produce Mw6.5 earthquake. The observed weak motion velocity data are used to find PGA (peak ground acceleration) at eight sites within 80 to 160km around the epicenter. The magnitude 3.5 earthquake is taken as an element earthquake and using this Mw 6.5 target earthquake is generated by EGFM technique in two step simulation. The calculated PGA in South Gujarat is varying from 50 to 80 gals and in Saurashtra region varying from 60 to 80gals within 80 to 160 km. This study represents that the Saurashtra and Mainland regions of Gujarat can expect PGA between 50 to 80 gals from an earthquake near Surat in Gulf of Khambhat. Key wards: Surat, Seismotectonics, Saurashtra, Gulf of Khambhat S14_P3 Site characterization using Vs30 and site amplification in Gujarat, India B. Sairam 1 ( B. K. Rastogi 1, Sandeep Aggarwal 1, K. S. Roy 1 A. G. Chhatre 2 and Rajesh Mishra 3 ( 1 Institute of Seismological Research, Raisan Gandhinagar, 2 NPCIL Mumbai, 3 RARC, Mumbai) Gujarat has experienced great earthquakes in historical past the last being on 26 January 2001 that struck Bhuj. The Bhuj earthquake (Mw 7.7) was one of the most destructive intraplate earthquakes of India, causing catastrophic damage and casualties to the state of Gujarat, killing about 15, 000 people, injuring many more. An intensity of X close to the epicenter has been estimated on a Modified Mercalli Intensity (MMI) scale. The Bhuj earthquake caused severe damage not only in the epicentral region, also spreading to over 350 km distance like Ahmadabad, Bhuj, Rajkot, Anjar, Gandhidham, Morbi, and Surendranagar. In these cities single to multistory buildings collapsed. Soil covered areas experienced higher damage than hard rock areas. Whole of Gujarat region has the earthquake hazard of different levels from moderate to high as zones II - V are assigned to it in the seismic zoning map of India. In the Gujarat region an earthquake of magnitude 5 to 8 can be expected. Thus, there is a great need for site characterization and seismic hazard mapping of the area. We have measured Vs profiles at 200 sites in different geological units viz Deccan trap (DT), Tertiary rocks (TR), Cretaceous rocks (CR), Limestone (LS), Jurassic rock (JR), Laterites (LT), Quaternary sediments (QS), including Holocene tidal flats (HTF) and estimated Vs30 of these geological units in the range of , , , , , , and m/s, respectively. These geological units are also classified according to NERHP classification based on their Vs30 which are: C-B type: DT and TR; C-type: CR, LS, JR, and LT; D-C type: QS and E type: HTF. Further, site amplification (SA) at 50 sites was estimated using earthquake records. The SA sites were well distributed and covered different kinds of geological units. The Estimated site amplifications of NERHP classes viz B, C, D, E are in the range of , , and , respectively. A plot of Vs30 versus site amplification is showing that the amplification increases with decreasing Vs30. From this observation it is inferred that Vs30 is a good proxy for site amplification. Each geological unit has been classified according to NEHRP classification based on Vs30. by doing this, we are creating site condition map of Gujarat where each site can be classified by a general geological category. then, these general geological units can be used to transfer Vs estimates of the geological units to SMA/SRR/industrial/nuclear power plant sites located on them these velocity estimates are used develop Next Generation Attenuation (NGA) relation applicable for different soil categories of Gujarat and also for generation of synthetic seismograms and response spectra January,

138 S15: Tsunami Modelling Convener: V.P.Dimri THEME East coast of India is affected by tsunami generated along Andaman-Sumatra subduction zone and west coast from Makran subduction zone. Numerical modeling to determine the tsunami propagation, potential run-ups and inundation from tsunamigenic sources is recognized as useful and important tool, since data from past tsunami are usually insufficient to plan future disaster mitigation and management planes. Models can be initialized with potential worst case scenarios for the tsunami sources or for the waves just offshore to determine corresponding impact on nearby coast. Models can be initialized with smaller sources to understand the severity of the hazard for the less extreme but more frequent events and also far taking into account the shape of the coast line and shelf. Paleotsunami study is important to decipher pre-historic tsunamis. All this information then forms the basis for creating tsunami evacuation maps and procedures. Papers are invited on these topics regarding tsunami studies. S15_C1 Hydrodynamic Modelling of 2004 Indonesian and 1945 Macran Tsunamis R. Rajaraman ( 1 Materials Science Group S. Joseph Winston (Metallurgy & Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam , TN, INDIA.) Hydrodynamic modelling of tsunamis has progressed extensively in recent times, thrust by the vast data recorded for the December 2004 Indonesian tsunami which swept across countries bordering Indian Ocean. This significantly enhances the verification and benchmarking the numerical models. Primary objective of these modelling studies is to improve on the advance warning systems towards the disaster mitigation efforts. Another crucial role of such tsunami modelling is to analyse impact of worst case scenarios for the specific coastal regions having thick population or infrastructures such as power plants. As part of the initiative by Department of Atomic energy, India to benchmark tsunami impact for Indian coasts, numerical modelling of 2004 Indonesian and 1945 Macran tsunamis has been carried out to estimate runup and inundation at select locations. Global propagation has been modelled using finite difference code, originally developed by C. L. Mader and implemented as part of MIRONE suit, with GEBCO bathymetry data. Local inundation computation has been carried out for select locations using finite volume code ANUGA with high resolution bathymetry and land elevation data. Spatiotemporal dependent orthogonal surface momentum and wave height histories derived from global propagation model were transferred to finite volume solver for accurate inundation studies. Owing to intensive computing resource requirements of high resolution inundation modelling, finite volume solver was run in parallel environment. Finite volume code has been benchmarked to reproduce one dimensional channel propagation studies of Kowalik and the 2D tank experiment of the Okushiri tsunami. This paper presents the results of the simulation of the Dec-2004 Indonesian Tsunami with specific emphasis for the eastern side as well as the 1945 Macran Tsunami for the western side of India. Inundation profiles and runups are compared with available field data, highlighting the satisfactory usability of such modelling for disaster mitigation preparedness for the entire Indian coast. S15_C2 Tsunami Assessment of Indian Nuclear Coastal Sites for Sumatra 2004 and Makran 1945 Tsunami Events R. K. Singh (Reactor Safety Division Bhabha Atomic Research Centre, Trombay, Mumbai , India), P Sasidhar (Safety Research Institute, Atomic Energy Regulatory Board, Kalpakkam, Tamilnadu, India) January, 2011

139 The two tsunami events due to Sumatra earthquake with magnitude 9.3 of December 26, 2004 and Makran earthquake with magnitude 8.1 of November 28, 1945 are of interest for the present and future prospective nuclear coastal sites of India. The tsunami generated due to Sumatra earthquake is well studied and reported, however, the Makran event has associated larger uncertainties due to lack of historical data. The paper describes a rational tsunami modeling and validation study for the run up and inundation assessment for Indian coastal sites with due consideration to the source term modeling for these two potential tsunami sources. Bhabha Atomic Research Centre, Trombay initially undertook computational simulation for all the three phases of tsunami source generation, propagation and run up evaluation for the protection of public life, property and various industrial infrastructures located on the Indian coastal regions for the National Tsunami Warning System. Further, studies have also been carried out for the protection of the coastal nuclear facilities. The site selection and design of Indian nuclear power plants require the evaluation of run up and the tsunami mitigation measures for the coastal plants. Besides it is also desirable to assess the early warning system for tsunamigenic earthquakes. The tsunamis originate from submarine faults, underwater volcanic activities, and sub-aerial landslides impinging on the sea and submarine landslides. In case of a submarine earthquakeinduced tsunami, the tsunami wave is generated within the ocean due to displacement of the seabed. These studies have been effectively utilized for design and implementation of early warning system for coastal region of the country in addition to the site evaluation of Indian nuclear coastal installations. The tsunami wave modeling using shallow water wave theory is first presented with in-house finite element code Tsunami Solution (TSUSOL) through numerical simulation of Sumatra-2004 and Makran tsunami events. The time signal analysis of the wave time history from TSUSOL code confirms the reflections from Sri Lanka and various other Indian islands. The reflected wave periods from Sri Lanka computed as 4096 sec, 2560 sec and 1280 sec compare well with the spectral periods of 4380 sec, 2580 sec and 1320 sec respectively from the detided data of NIO tide gauge records. The tsunami January, 2011 source modelling with regard to the fault parameters, fault multiple segments and orientations are described to identify and characterize the tsunamigenic earthquakes in Indian Ocean. The TSUSOL code is shown to have special capability of coupled tsunami and acoustic wave simulation, which is an important feature for the early warning system. Coupled seabed and water column dynamic models are proposed for identifying the tsunamigenic earthquakes with help of tide gauge wave form time signal analysis and the associated tsunami periods and wave lengths. As an inter-code comparison and code benchmarking exercise, using a refined local bathymetry and land morphology data, detail inundation modelling has been carried out for Kalpakkam nuclear site in South India for tsunami event of Sumatra-2004 with different tsunami numerical codes through a systematic National Round Robin Exercise with participants from research, academic and technical organizations. Detail computational results of inundation reach and wave run up for Kalpakkam site are presented and are shown to have reasonable comparison with the post tsunami measurements carried out after the Sumatra-2004 tsunami event. A sensitivity analysis of the results obtained from the different codes is carried out with regard to various modelling schemes and assumptions. The influence of bottom friction and Coriolis forces and issues of coupling of storm surges with tsunami waves to evolve the design basis for the coastal nuclear facilities have been addressed. The result of this assessment has been further utilized for tsunami hazard evaluation of coastal nuclear plants in India. For the Makran event, Tarapur site has been chosen for detail inundation and run-up study. The eastern and western halves of Makran subduction zones have different seismic patterns. The regions of western coast have very shallow depths and separation between the global and global models was arrived from the modelling experience of Sumatra event. This resulted into mminimization of the numerical dispersion and diffusion in the multi-grid models to capture natural physically consistent amplitude dispersion and phase dispersion for accurate inundation and run-up modeling. 109

140 Keywords: Tsunami hazard, coastal nuclear sites, inundation height, tsunami modelling, numerical codes. S15_C3 Development of Paleo-Tsunami Database and Hazard Assessment for Indian Subcontinent from A & N Islands Akhilesh K. Verma and William K. Mohanty ( (Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur , India) Many destructive tsunamis have occurred in the Indian Ocean and in the Mediterranean Sea although the frequency of occurrence is very less as compare to the Pacific Ocean. In the present study, a paleotsunami database has been prepared for Indian subcontinent from various sources such as NOAA/ WDC. The Indian coastal belt has not recorded many tsunamis in the past. Most of the events recorded are true paleo-tsunamis that occurred prior to the historical record or have no written observations. The one well documented devastating shallow megathrust earthquake-cum tsunami (M W >9) of December 26th, 2004 occurred on the interface of the India and Burma plates and was caused by the release of stresses that develop as the India plate subducts beneath the overriding Burma plate. Almost all the countries situated around the Bay of Bengal were affected by the tsunami waves during this destructive event. The resulting tsunamis from Indian Ocean devastated the shores of Indonesia, Sri Lanka, India, Thailand, and other countries, even reaching the east coast of Africa, 4500 km (2,800 miles) west of the epicenter. The Andaman and Nicobar (A&N) islands in the southeast of mainland India are the Indian land masses closest to the epicenter of the 26 December 2004 event. Commenting on the recent earthquake that occurred, the Andaman and Nicobar Islands took place in a most seismically active region in the world and at the plate boundary separating the Indian-Australian and East-Asian Plates. In addition, we have also carried out the maximum magnitude (m max ) and the b value for this tectonically active region. The m max is estimated for Andaman and Nicobar region only, the earthquake catalogue do not include the 26th, 2004 event of moment magnitude 9.3. The estimated maximum possible magnitude (m max ) and b value for the Andaman and Nicobar region are 8.2 ±.54 and 1.05 ±.02 respectively. The maximum observed magnitude in this region was 7.7. This preparation of database and hazard analysis may efficiently useful to improve our understanding about tsunami sources, even its magnitude and frequency. Keywords: Paleo-tsunami, database, India, Andaman and Nicobar Islands, m max, b value, Hazard assessment. S15_C4 Tsunami Effect on Porbandar, Western Gujarat Coast. V. M. Patel 2 ( H. S. Patel 2 ( A. P. Singh 3 ( ( 1 Ganpat University, Ganpat Vidyanagar, Mehsana , Gujarat, India. 2 Department of Applied Mechanics, L. D. College of Engg., Ahmedabad, Gujarat, India. 3 Institute of Seismological Research, Gandhinagar, Gujarat, India.) Almost all of the recorded tsunamis along the Arabian Peninsula have occurred on its eastern and southern edge, some, such as the one formed by the 1945 Makran earthquake, were extremely destructive. The Indian Ocean is the most likely source area for future destructive tsunamis (Jordan, 2008 & Rastogi, 2006). The most significant tsunamigenic earthquake in recent times was that of 28 November :56 UTC (03:26 IST) with a magnitude of 8.1 (Mw). In this paper an attempt is made for a numerical simulation of the tsunami generation from the Makran Subduction Zone, and its propagation into the Arabian Sea and its effect on the Porbandar city of Gujarat, India, through the use of a numerical model. It is observed from the results that the simulated arrival time of tsunami waves at the Porbandar is in good agreement with the available data sources. In this study more importance has been given to the run up height of tsunami waves, arrival time and inundation map. Also effect of different fault parameters on basic data is also studied January, 2011

141 Keywords: Earthquake, Tsunami, Makran Subduction Zone (MSZ), Numerical Modeling, Porbandar. S15-P1 Numerical modeling of Arabian Sea tsunami propagation and its effect on the Gujarat Coast (India) as well as tsunami directivity from Makran and Andaman-Sumatra sources A. P. Singh ( and B. K. Rastogi (Institute of seismological research (ISR), Raisan, Gandhinagar , Gujarat (India)) Historically, tsunamis are a reality in the Arabian Sea and one of the most deadly tsunami ever in the region occurred on 27th November Seismologists are concerned about the possibility of the occurrence of tsunami in this region again. Therefore, it is important to know about the impacts of tsunami wave on Gujarat coastline, especially the extent of inundation in coastal towns. Mathematical modeling of tsunami provides an effective tool to know about the tsunami propagation and its impact on land. The shallow water non-linear mathematical model TSUNAMI- N2 is used for tsunami propagation and inundation. In this model, a set of nonlinear shallow water equations with bottom friction term are discretized by the leap-frog finite difference scheme. The model generates the water level displacement in model domain at given time intervals for all nested grids and maximum water level displacement at each grid cell independently of the time when it occurred. For the modeling of tsunami, open source bathymetry and topography data (GEBCO) which is available at 1 minute interval is used. The fault parameters of the earthquakes for the generation of tsunami are strike 270 0, fault area (200km length and 100km width), angle of strike, dip and slip (270, 15 and 90 ), focal-depth (10 km) and magnitude of 8.0. For this study, the initial vertical displacement of the sea bottom is calculated with the Mansinha and Smylie (1971) method. The initial displacement is generated in the study area with the hypothesis that the sea bottom displacement is immediately reflected in a sea surface displacement. If the strike is 250 0, the directivity is towards India. The simulation of model results were stored in an animation movie at every minute using MATLAB and found that the tsunami wave propagated initially very fast in Arabian Sea and slowed down when it reached shallow sea near Gujarat coast, Gulf of Kachchh and Gulf of Cambay. At the source, it generates 6-7 m tsunami at the moment of the earthquake. At Dwarka, positive tsunami waves arrive within 2 hours and 10 minutes and Mandvi it takes 3 hours 10 minutes, if the source is eastern Makran. If the fault strike is 250, the travel time reduces. However, if the source is considered along the western part of Makran, the travel time increases by twenty minutes. The tsunami strikes Dwarka, Jakhau and Porbandar with 2.0, 2.5 and 1.5m runups, respectively. If the tsunami strikes during high tide, we should expect more serious hazard which impacts local coastal communities. The study of tsunami inundation along Gulf region shows that there is no impact during low water in inner gulf, however, a combined effect of high water and tsunami wave has a great impact inundating up to 1200 m in Mandvi area. Directivity of Andaman-Sumatra, 1300 km long source zone is studied by dividing it into five segments. Each segment is assumed to have different fault parameters. The northern three segments comprising Andaman-Nicobar belt are found to be contributing to the tsunami affecting east coast of India and directivity of the southern two segments comprising Sumatra is away from India. The combined effect of all the segments is also estimated. This estimate gives 7-8 m run up at Nagapatanam, the most affected place in India during December 2004 tsunami January,

142 S16: IGCP Session on Archeoseismology Conveners: Prof. Manuel Sintubin and Dr. Javed Malik. THEME The session on Earthquake Archaeology in Central and Southern Asia invites case studies that consider the principles and/or practices of archaeoseismology within the broader Himalayan seismic zone in Central (e.g. Afghanistan, Tadzhikistan, Kyrgyzstan, Tibet) and Southern Asia (e.g. India, Pakistan, Nepal, Bangladesh). This session is organized in the framework of the international geosciences programme IGCP567. S16-IGCP_Keynote-1 Archaeoseismology and the role of tectonics in the demise of the Indus Valley Civilization Pradeep Talwani (Department of Earth and Ocean Sciences, University of South Carolina Columbia, SC, 29208, USA) The study of how earthquakes affect archaeology, archaeo-seismology, is a nascent forensic science where in archaeologists are beginning to appreciate the role of earthquakes in the destruction of structures and earth scientists are beginning to decipher archaeological ruins to fill gaps in their knowledge of prehistoric earthquakes and improve seismic hazard assessment in a region. Recent archaeoseismological studies have shown the role of earthquakes in the destruction of major structures and end of many civilizations in the seismically active region in and around the Mediterranean Sea. Some of the techniques employed in archaeoseismology include the identification of the affects on structures of the horizontal and vertical ground movements on which they are built, and on the patterns of destruction due to shaking. Several causes have been attributed to the sudden end of the Indus Valley Civilization, ~2500 to 1700 years before present. Among these, a cause I will explore in my talk is the role of tectonics. I will also explore the possibility of conducting archeoseismological investigations to decipher the ancient earthquakes that leveled Dholavira, the ruins of which lie on the seismically active Island Belt fault. S16_IGCP-I1 Major Earthquake Occurrences in Archaeological Strata of Harappan Settlement at Dholavira (Kachchh, Gujarat) R.S. Bisht ( Former Joint Director General, Archaeological Survey of India, 9/19 Rajendra Nagar III, Sahibabad, Ghaziabad, U.P Archaeological excavation at Dholavira, District Kachchh, Gujarat, (during ) has suggested that the Harappan settlement thereat visited by at least three major seismic episodes of intense magnitude at different time-periods during the third millennium BCE. Significantly, the first two brought about qualitative changes in the planning as well as in cultural form, of course, for good as the state of economy was healthy and growing, while the third one dealt a fatal blow to the mature Harappan city and forced the inhabitants to abandon the settlement because the already tattering financial condition did not enable them to undertake large-scale damages that have been wrought. It is necessary to state at the outset that the signatures of all the three devastative earthquakes are best evident in the castle, which was the most important, most attractive and towering component of the Harappan settlement. A deep gully cut by the rain water across the southern arm of the fortification wall of the castle was considered to make a deep probing with a view to obtaining a cultural sequence vis-à-vis growth of defences which incidentally provided evidence for successive earthquakes, at least the first two January, 2011

143 First earthquake occurred towards the close of the cultural Stage II, possibly sometime after 2900 BCE. Its signatures are found in the occupational strata, deposited against the fortification walls of the first two stages. All those layers show two vertical breakages and as many dislocation, i.e. subsidence, more pronouncedly in those floor layers which were made of compact earth or clay. All strata slightly slid towards north causing a small bulge a little further where two mud-brick walls of two different stages worked as bulwark. Furthermore, both the houses walls were considerably impacted, so much so their bricks got badly crushed. Second earthquake was far more devastative. It brought about end of Stage IIIA, sometime around 2700 BCE, when the mature Harappans were yet to arrive on the scene. A large chunk, measuring 7.60 m wide, of which 2.80 m height is now extant, collapsed and slipped away. Additionally, 4.00 m wide portion of the wall, behind the collapsed part, got partly dislodged and smashed or deeply fissured. The latter may still be seen behind the later reconstruction. This effected part which was retained still show dislodgment, smashing and slipping of brick work. A horizontal cross section portion of thus impacted wall has shown multiple cracks running almost parallel in E-W direction, which are reflected on the vertical section as well. Another piece of evidence of this occurrence was seen beside an inner bastion. The southern face, of this structure collapsed and its stone were found lying helter-skelter during excavation. Tell-tale marks of this visitation could be seen elsewhere too. Third earthquake resulted in the end of the mature Harappans stay at the site, somewhere during BCE. It caused tremendous damage to the gates of the castle. Particularly, the north gate retained the impact in the form of tilting and arching of the enormously thick inner walls while the outer ones seem to have collapsed at the first tremor itself. In the southern arm of the castle, a 6.30 m part of the wall slipped from the top. The quake must have razed most of the residential houses down to the ground. But the evidence was hard to find because the later Harappans, who came to occupy the site after a gap of many decades, had collected the stones and even robbed the pre-existing ruins to build their defences and houses, thus obliterated the signs of the damage. Here, its seems worthwhile to recall that all the houses of the ultimate phase, so far excavated at another Harappan site, Juni Kuran in the Khavda Bet (Kachchh), were found to have been collapsed towards the south. This is the observation and interpretation of an archaeologist who knows a little of seismology. S16_IGCP-C1 Archaeological Evidences for a 12 th -14 th Century Earthquake at Ahichhatra, Barreilly (U.P.), India Bhuvan Vikrama 1 ( S. Sravanthi 2 ( Javed N Malik 3 ( Onkar Dikshit 4 ( ( 1 Archaeologist, Archaeological Survey of India, Agra., 2 PhD Student, Department of Civil Engineering, IITK, Kanpur., 3 Associate Professor, Department of Civil Engineering, IITK, Kanpur, 4 Professor, Department of Civil Engineering, IITK, Kanpur) In India archaeo-seismology is still in its infancy, despite the claim of the earliest archaeologically dated earthquake at Kalibangan was made as early as This and such other claims were supported more by wishful thinking and surmises rather than by varied and numerous archaeological evidences. Recent excavations at Ahichhatra, located in the Upper Gangetic Plain in the wet-lands between Himalayan foothills and river Ganga, have revealed evidences which may indicate towards an earthquake event causing proverbial end to the dwindling city. Recent paleo-seismic investigation in the Central and January,

144 North-West Himalayan Foothills suggests occurrences of a few major paleo-earthquakes during 1000 AD-1500 AD (Lave et al., 2005; Kumar et al., 2006; Malik et al., 2008). It has been suggested that ~1100 AD a major earthquake occurred along Main Frontal Thrust with a surface rupture of about 200 km 300 km along the strike of the fault in the foothill zone (Lave et al., 2005). Another set of events are been reported to have occurred during 984 AD AD around Ramnagar in Central Himalaya (Kumar et al., 2006) and along North-West Himalayan foothills during ~ AD (Kumar et al., 2006; Malik et al., 2008). Thus the major earthquake events those occurred during 1100 AD AD were responsible for the destruction of the Ahichhatra and in particular probably the AD events (?) from Ramnagar located about 120 km from Ahichhatra contributed to total destruction of the site. This paper envisages to list all such evidence from Ahichhatra and test them on the whetstone of the reasoning and archaeo-seismological parameters. An attempt will be made to date the event archaeologically and understand the relationship to the paleo-earthquake event. S12_IGCP-C2 Active Fault Influence on the Evolution of Landscape and Drainage: Evidence from Lateral Propagation of a Branching Out Fault along Himalayan Front and Deflection of Dabka River, Kumaun, Himalaya Javed N. Malik ( Ph: , Fax: ), Sambit P. Naik, A. A. Shah and N. R. Patra (Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur Uttar Pradesh, India The geomorphology and drainage patterns in an area of active fault and related growing fold provide significant information on the ongoing tectonic activity. The Kaladungi fault, an imbricated thrust fault of Himalayan Frontal Thrust (HFT) system provides one such excellent examples of forward and lateral propagation of fault and related folding. This fault has displaced the Kaladungi fan surface along it, which is well revealed by variable heights along the front. In the east, the uplifted fan surface is much higher (~140 m) as compared to the west (~60 m). The variation in heights along the fault line can be attributed to the lateral propagation of faultfold towards northwest. The northwestward propagation of the Kaladungi fault has resulted into diversion of the Dabka River. A marked diversion of the modern Dabka River along its present course from east to west direction can be traced between the Pawalgarh and Karampur towns covering a distance of about 7-8 km. The diversion of Dabka River can well be justified by the existence of paleowind gap through which it flowed earlier in the recent past. The wind-gap is characterized by about km wide incised valley extending in NE-SW direction from Pawalgarh right up to the front From our studies we conclude that initially the tectonic active propagated forward along the Kaladungi fault, and then the fault started propagating laterally towards west causing diversion of the Dabka River. Keywords: Active fault; lateral propagation; River diversion; Dabka River; Central Himalaya. S16_IGCP-C3 Signatures of active faulting in Southern Peninsular India Biju John, D.T. Rao, Yogendra Singh and P.C. Nawani (National Institute of Rock Mechanics, Kolar, Karnataka) Peninsular India was considered as seismically stable until the most devastating 1993 Latur Earthquake (M=6.3) occurred in this region. Most of the source zones in peninsular India could not be identified before bigger earthquakes, mainly due to their long recurrence intervals. Thus it is important to identify such source zones through geological and geomorphological studies. Recent studies in the region south of Palghat Cauvery shear zone, identified two NW-SE trending source zones viz. Desamangalam and Periyar faults, in the Western Ghat region based on the geological and geomorphological evidences. In the present study another possible NW-SE trending source zone is identified in a flat terrain in the southern Tamilnadu, where most of the drainages are seasonal. Regionally this lineament is sympathetic to Achancovil shear zone of Pan African orognesis January, 2011

145 ( Ma). The major drainage of the area, Karamaniyar River, is flowing along the part of this lineament in the study area. The trace of the fault is visible both in crystalline and Miocene formations and is associated with distinct geomorphic features on either side. In the east coast, this fault shows an elevated perturbation of southwestern portion of landmass towards sea whereas beach rocks are not exposed in the northeastern side of the land mass. A major drainage seems to be abandoned in the southwestern block of the fault whereas a big natural pond developed in the northeastern block in the study area. Our field studies identified a zone of fractured laterite extending beyond 500m in the hard capping (vermicular laterite) of the crystalline rocks. The deformation zone is charaterised by open cracks as well as reverse movement where no further leaching after the fracturing. This may indicate that the fracturing might have occurred after ending of the laterization process. The style of the deformation exhibits similar to that of surface rupture associated with Latur Earthquake and may be indicating the prevalence of compressive tectonic regime even at the southern end of Peninsular India. S16_IGCP-C4 Macroseismic Intensity Assessment of 1885 AD Historical Earthquake of NW Kashmir Himalaya, Using ESI Scale Bashir Ahmad ( G.A. Mukhtar #, A.S. Mahmood $ (* Department of Education, J&K, Srinagar, India # Jammu and Kashmir Power Development Corporation, Srinagar, India $ Directorate of Tourism, Jammu and Kashmir, Srinagar, India) Kashmir Valley having long history of 5,000 years provides a sketchy picture of historical earthquakes. In all we collated details of 18 earthquakes from the historical scribes. While most of the earthquakes may have their epicenters outside the Kashmir Valley, and few which caused severe demage to life and property and were associated with ground ruptures and long periods of aftershocks seems to have been appeared within the Valley. Of these, only 1885 AD event is well documented. We analyse environmental effects of this ruinous earthquake which occurred along Pir Panjal range of NW Kashmir Himalaya in the early January, 2011 morning (5.00 a:m) of 1885 AD. The present attempt envisages to implement ESI 2007 macroseismic intensity scale where in archival sources have been consulted. The effects (primary and secondary) induced by 1885 AD event to the environment reveals that intensity would have been VIII IX on ESI scale which correspond to on RF scale and probably on Richter scale. It has been further inferred that the intensity must have been variable all along the Epicentral tract (severe at Baramulla less at Srinagar) because of the severity of demage decreasing from NW to SE direction. S16_IGCP-C5 Fault segmentation and propagation characteristics based on rupture patterns and slip distribution along the 1957 Gobi-Altay earthquake rupture, Mongolia Jin-Hyuck Choi 1, Kwangmin Jin 1, Amgalan Bayasgalan 2 and Young-Seog Kim 1 ( ( 1 GSGR, Dept. of Earth Environmental Sciences, Pukyong National University, Busan , Korea., 2 School of Geology and Petroleum Engineering, Mongolian University of Science and Technology (MUST), Ulaanbaatar, Mongolia.) The 260km-long surface rupture associated with the 1957 Gobi-Altay earthquake (Mw=8.1) occurred along the WNW-ESE or EW-trending Bogd leftlateral strike-slip fault in SE Mongolia. Some dip slips were reported around the secondary thrust and normal faults locally developed along the fault. However, detailed study on slip distribution, fault segmentation and propagation along this rupture has not been carried out. In this study, geomorphologic and geological investigations including measurement of the amount of horizontal- and vertical-slips are carried out to interpret rupture patterns and characteristics of slip distribution. Based on the earthquake information, the surface rupture was initiated near the western end of the rupture and propagated unilaterally eastwards. The left-lateral slip along the rupture up to 7.0 m and with m of average displacement. Although the Bogd rupture propagated through many geometrical oversteps, abrupt changes of slip occurred only at three oversteps. Based on the 115

146 rupture patterns and slip distribution, the Bogd surface rupture is composed of three segments; North-Ih, East-Ih and North-Baga Bogd segments from west to east. The eastern tip damage zone is characterized by widely developed minor ruptures (conjugate faults, mole tracks, and tension cracks) with small displacements (less than 1m) rather than the western tip zone. The slip distribution pattern indicates that oversteps act as barriers against rupture propagation. This supports that structural maturity of step-over zone is one of the main controlling factors on rupture propagation. The asymmetric tip damage pattern is also well consistent with the unilateral propagation of the 1957 earthquake. Slip distribution indicates that the easternmost overstep acted as a strong barrier, and the displacement is decreased and the eastern tip damage structures may be developed to accommodate the releasing stress. Detailed analyses on the 1957 earthquake rupture patterns and slip distribution indicate; 1) minor ruptures are concentrated at fault linkage and tip zones, and their damage patterns strongly resemble the suggested fault damage model, 2) characteristics of step-over zone highly affect fault propagation and termination. These results indicate that fault segmentation and propagation are very important factors to fault damage patterns and amount of slip along earthquake ruptures. S16_IGCP-C6 Preliminary study on active faults around Mandi region, NW Himalaya, India Javed N. Malik ( Santiswarup Sahoo (Department of Civil Engineering Indian Institute of Technology, Kanpur , Uttar Pradesh, India.) The Mandi area in Himachala Pradesh falls under meizoseismal zone of 1905 Kangra earthquake in northwest Himalaya. Preliminary satellite photo interpretation revealed offset of streams, linear valleys and occurrence of fault scarps along the NNW-SSE striking faults with right-lateral sense of movement near Mandi and Marathu villages. Most prominent stream offsets were considered near Mandi and Marathu areas to calculate the slip rate along the faults in both the segments. In order to calculate the slip rate, the offset ratio (a=d/l) as suggested by Matsuda (1975) was used, where D is the offset of the streams along the faults and L is the upstream length of the respective stream. The average slip rate along both the segments is about 4.9 ± 0.15 mm/yr. The preliminary identification of active fault trace extending for about 20 km suggests that this fault can produce an earthquake of M>6.5. Further studies are in progress, which will be great significance towards better evaluating the seismic hazard of this region. IGCP-C7 Archaeology of Earthquakes at Mahasthanghar (Province of Bogra, Bangladesh) Bruno Helly 1, Ernelle Berliet 2, Barbara Faticoni 3 ( 1 Directeur de recherche au CNRS (émérite), membre de la Mission franco-bangladaise de Mahasthanghar, Maison de Orient et de la Méditerranée Jean-Pouilloux, Université de Lyon, 7, rue Raulin, F LYON (France)., 2 Archéologue, membre de la Mission franco-bangladaise de Mahasthanghar, École Française d Extrême Orient,Bangkok. 3 Archéologue, membre de la Mission franco-bangladaise de Mahasthanghar, Université La Sapîenza, Rome (Italie)). At about twenty miles northwest of the present town of Bogra, north of the confluence of the Ganges and Brahmaputra, is the ancient walled city of Mahasthan. Beyond the fortifications, the suburban area from ancient times spread over a radius of 8 to 9 km outside the walls, with theexception of the eastern side limited by the course of Karatoya, a river that has largely contributed to the prosperity of the city and which also marks the limits of expansion of the site. A high brick wall, surrounded by a road defines urban space itself about 1.5 km long by 1 km wide. The remains of the ancient city were discovered and identified for the first time by F. Buchanan Hamilton, 1808.But it was not until 1879 that Sir Cunningham identifies Mahasthan as the ancient city of Pundranagar reported by the texts. The first regular excavations at Mahasthan were conducted between 1928 and 1933, then sporadically until 1936, by the Indian archaeologist K.N. Diksit January, 2011

147 of the Archaeological Survey of India. The latest research at Mahasthan is developped as a cooperative program run by a Franco-Bangladesh since 1993 under the direction of Jean-François Salles. The early campaigns ( ) concentrated on an area called Rampart East aimed at establishing the whole stratigraphic sequence and timing of the city and its evolution. The layers were well preserved since the oldest dating in IVe century BC levels until the latest dating from around the twelfth century AD. In view of analyzing the levels of medieval and modern occupation, an excavation program was launched in 2001 in south-eastern city on the plateau of Mazar, the highest point of the city. They revealed a residential area which corresponds to the last period of occupation of the site and whose remains offer clear traces of violent and simultaneously destruction that can probably be attributed to an earthquake. Recent campaigns ( ) on the wall that limits the area of the city have helped to clarify this hypothesis and to refine the chronology of events : the construction of this wall in the oldest period, the successive phases of reconstruction, particularly after a siege of a rare intensity, and finally the final phase of a wall hastily restored before being permanently ruined by the earthquake that ended the history of the city. À une vingtaine de kilomètres au nord-ouest de l actuelle ville de Bogra, au Nord de la confluence du Gange et du Brahmapoutre, s élève ville fortifiée de Mahasthan. Au delà des fortifications, l espace suburbain des temps anciens s étend sur un rayon de 8 à 9 km hors les murs, à l exception de la face orientale limitée par le cours de la Karatoya, une rivière qui a largement contribué à la prospérité de la ville et qui marque également les limites de l expansion du site. Un haut rempart de briques, bordé d un fosse (douve?), délimite l espace urbain proprement dit sur 1,5 km de long par 1 km de large. Les vestiges de l ancienne cité ont été découverts et repérés pour le première fois par F. Buchanan Hamilton, en Mais ce n est qu en 1879 que Sir Cunningham identifie Mahasthan comme étant la ville antique de Pundranagara relatée par les textes. Les premières campagnes de fouilles régulières à Mahasthan ont été menée entre 1928 et 1933, puis de manière plus sporadique jusqu en 1936, January, 2011 par l archéologue indien K.N. Diksit de l Archaeological Survey of India. Les recherches les plus récentes s inscrivent dans le cadre d un programme de coopération mené par une équipe franco-bangladaise depuis 1993, sous la direction de Jean-François Salles. Les premières campagnes ( ) concentrées sur un secteur nommé «Rempart Est» visaient à établir l ensemble des sequences stratigraphiques et chronologiques de la ville et de son évolution. Les couches étaient bien préservées depuis les plus anciennes remontant au IVe s. av. jusqu au niveau datant des environs du XIIe siècle ap. J.-C. Dans la perspective d analyser les niveaux d époque médiévale et moderne, un programme de fouilles a été lance en 2001 au sudest de la ville, sur le plateau de Mazar, le point le plus élevé de la ville. Ils ont révélé un quartier d habitation qui correspond à la dernière période d occupation du site et dont les vestiges portent clairement les traces d une destruction violente et simultanée que l on peut probablement attribue r à un séisme. Les campagnes récentes ( ) sur le rempart qui limite ce secteur de la ville ont permis de préciser cette hypothèse et d affiner la chronologie des événements : la construction de ce rempart dans la période la plus ancienne, les phases de reconstruction successives, notamment suite à un siège d une rare intensité, et enfin la phase finale d une muraille hâtivement restaurée avant d être définitivement ruinée par le séisme qui a mis fin à l histoire de la cité. S16_IGCP-C8 Archeoseismology of the A.D earthquake in Chiang Mai, northern Thailand Miklos Kazmer 1 ( and Kamol Sanittham 2 ( 1 Department of Palaeontology, Eotvos University, Pazmany Peter setany 1/c, H-1016 Budapest, Hungary. 2 Department of Mathematics and Statistics, Chiangmai Rajabhat University, Chiang Mai, Thailand) The A.D Chiang Mai earthquake in Thailand is one of the few ancient seismic events, when both historical documentation and the hard evidence, the smoking gun is available. We studied the Buddhist temples in and around the old city of Chiang Mai to 117

148 identify possible earthquake-induced damages preserved in the buildings structure and orientation. The earthquake occurred on 28 July 1545, in the afternoon hours between 4.30 and 6.00 pm. The well-known Wat Chedi Luang highest chedi ever built on the alluvial soil of the Chiang Mai- Lamphun Basin has lost about half of the original 80-metres height, due to southward-directed collapse. We visited further seventy-four temple sites in search for earthquake-induced damages. Twentyone sites display tilting of the chedi, up to 5 systematically either in northward or southward direction. Data for pre-1545 construction of temples are mostly available. We suggest that a city-wide liquefaction event occurred related to the A.D earthquake. North-south-directed strong motion destroyed the Wat Chedi Luang, and affected other, significantly smaller buildings of different vibration characteristics. An area of at least 4 km 2 suffered liquefaction extended on the Ping River alluvial plain, where ground-water level is often less than 1 m below ground. Liquefaction is mostly attributed to nearby epicentres (within 3-4 km). We suggest that the activity of the nearby Doi Suthep fault westward of Chiang Mai city is responsible for both the desctruction of Wat Chedi Luang and the liquefaction-induced tilting of many other chedis in the area. The Doi Suthep low-angle normal fault is currently regarded as inactive. It is the western master fault of the half-graben of the Chiang Mai Basin. Its Miocene activity produced the km-thick sedimentary succession of the basin, while allowing the uplift of the Tertiary metamorphic core comples of Doi Suthep. Its continued activity in the Holocene is evidenced by the extensive alluvial plain of Ping River extending westwards just to the foot of Doi Suthep Mountain. Currenty earthquake activity in northern Thailand in interpreted within the framework of Thoen Fault (Chiang Saen, May 2007, M L = 6.3), Mae Tha and Pha Youv fault zones tens of kilometres away. Since recurrence time of major earthquakes seems to be longer than the instrumental period of 50 years, archaeoseismology is a necessary tool to extend the observation period to centuries. S16_IGCP-C9 Paleoseismological analysis in north of Dushanbeh, Tajikistan H. Nazari, 1,2 M. Qorashi, 2 A. Ibrohim, 3 M. Shokri, 1 A. Fathian, 1 R. Juroyov 3 and B. Oveisi 1 ( 1 Geological survey of Iran, Seismotectonic group, P.O. Box , Tehran, Iran., 2 Institute for Earth Science, Geological survey of Iran, P.O. Box , Tehran, Iran., 3 Geological Survey of Tajikistan Dushanbeh, capital of the Tajikistan with 680,000 population, Standing at south of the Hissar range that is surrounded by several active faults. Height of the Hissar with WNW-ESE trend are including of metamorphosed and nonmetamorphosed rocks of Paleozoic to Mesozoic that are covered by Neogene deposits in south of Dushanbeh. Regard to morphotectonic features and lack of instrumental and historical earthquakes in this area, it is necessary to know about active faults and past seismicity of them for a better perception of seismic hazard in Dushanbeh city. paleoseismology is one approach that we can use for this purpose. In this study we used satellite imagery (Spot; with pixel size 2.5m, SRTM data with 90m resolution), digital topographic model made by kinematic GPS and field observation during June 2010 to identify geometry and kinematic patterns of the most important fault near the Tajikistan capital. In order to identify paleo events, we dug two trenches at north of sheikhan village along an active scarp. Measured apparent Vertical and leftlateral displacement on a ridges axis are 19 and 12 m respectively. Trench 1 with 33m in length, 1.5m wide and ~3.5m high, located in N 38Ú , E 68Ú Trench 2 in downstream of trench 1, with 15m in length, 1.5m wide and ~3.5m high, is located in N 38Ú , E 68Ú Six and three units observed in the eastern wall of the trench 1 and 2 where the trenches dug in cream to light brown loess deposits respectively. Our field observation and drown logs on the trench 1 and 2 allow us to interpret 2-3 paleo earthquakes due to reactivity of an active fault on this studied area January, 2011

149 Keywords: Paleoseismology, Trench, event, Dushanbeh, Tajikistan S16_IGCP-C10 Archaeoseismological approach based on stone heritages in Gyeongju, SE Korea M. Lee and Y.-S. Kim * ( of Geosciences, Pukyong National University, Busan , Korea) The Korean peninsula is located within the relatively safe Eurasian intracontinental region. However, in some neighbouring countries around Korea such as Japan and China, big earthquakes have occurred frequently. However, according to the Korean historical records, some big seismic events affected Korea peninsula. Furthermore, over 20 quaternary faults are recently discovered along the Yangsan and Ulsan faults located in south-eastern part of Korea. Gyeongju, which is located between these faults, is represented as an oldest capital city in Korea. Therefore, there are many cultural heritages and historical records to study on. According to the historical records, the Gyeongju area has experienced several big earthquakes, which have resulted in extensive damages to the heritages. Deformed manmade structures with recognized age and original state can offer supplementary information on past earthquakes. For this study, we will apply the Earthquake Archaeological Effects (EAE) - ESI07 macroseismic scale - and statistic analysis on destroyed stone heritages such as pagodas and ramparts. In addition, we will collect historical and instrumental earthquake data to figure out the characteristics of the past seismic activity in Korea. This study can give some useful information to paleoseismic and earthquake hazard studies in Korea. S16_IGCP-C11 Discover and the Characteristic Initially Search of Gaixia Ruins s Nature Distortion Vestige, Guzhen County, Anhui Province, P.R.China 1 YAO Da-quan(Seismological Administration of Anhui Province, Hefei,Anhui P.R.China,230031, January, 2011 During recent years, with the large-scale economic construction in Eastern China, such as highway, highspeed railway and other major projects under construction have excavated a large number of ancient sites, ancient tombs, which make it possible to identify and trace for thousands of years of natural deformation history in Eastern China. Recently, the earthquake department with the cultural relic archaeology department cooperation, to conduct the special excavation research to Anhui Guzhen Gaixia ruins archaeology scene, the fault and the crack are discovered.the preliminary study to demonstrate both for the different time stratum dislocation event s vestige, and the time approximately to be equal to the Dawenkou culture stage. The fault and crack located in the same culture layer, displaying tension deformation, which occurred in the culture layer of the plastic clay soil, should be the fast fracture remains, and in particular, the movement traces of the upwards flow of sand along the crack as the flame appearance, shows a typical stick-slip mark. According to the combination of the cultural relic pieces of the culture layer, this culture layer belongs to the Late Dawenkou Dynasty. But they still show difference: The fault is a tensile shear, showing tension shear fracture; the crack is tensile, showing tension cracks; They ended in the bottom of the different overlaying cultural layers. The time of the crack formed was earlier, and may represent twice stick-slip events. The specific time is to be proven by further study. To analyze the seismogeology environment of the vestige, the location lies on Tancheng-Lujiang fault in NNE trending. According to the history records, several earthquakes of Ms6 occurred near this area. Our discovery of this earthquake ruins enriches the new deformation activity in this area. 4 This paper is a contribution to Scientific Research Special Project of the Earthquake Calling ( ) and Science and Technology Tackle Key Problem Plan Project of Anhui Province ( ) 119

150 S16_IGCP-C12 Paleo-earthquake evidence from archaeological site in mesoseismal zone of 1819 Allah Bund event, Great Rann of Kachchh, Gujarat, Western India Malik J N 1, Gadhavi M S 3, Ansari K. 1 Dikshit O 1, Chiranjeeb Banerjee 1, Falguni Bhattacharjee 2, A. K. Singhvi 4 and B. K. Rastogi 2 ( 1 Department of Civil Engineering, Indian Institute of Technology Kanpur 2 Institute of Seismological Research, Gandhinagar, 3 L. D. College of Engineering, Ahmedabad, 4 Physical Research Laboratory, Ahmedabad) The Kachchh region in seismic zone V is not only well known for the occurrence of large magnitude earthquakes occurred in 1668 (M7); 1819 (M7.7±0.2), 1956 (Ms6.1), and 2001 (Mw7.6), but also for having major Harappan ( year) and historical sites. One of such major sites was Dholavira located on Khadir Island. Few sites in Great Rann of Kachchh (GRK), probably flourished until 1819 Allah Bund earthquake (?). Till date it is not fully understood as whether these sites were affected by the major seismic events in the past and also the presently evolved landscape was influenced by tectonic movements. The geologists, archaeologists, and scholars of ancient Indian history have mentioned the existence of numerous mighty southwest flowing rivers viz. the Sindhu (Indus), Shatadru or Nara (Sutlej) and Sarasvati, during Pre- Vedic and Vedic times (~4000 yr). These rivers flowed into then existing Arabian Sea, presently the GRK. We excavated 6-8 trenches in Allah Bund region GRK. Study reveals occurrence of at least 3 major events during recent past, which were probably responsible for the disruption of major channels (?), changing the landscape and destruction of the settlements. Trenches on the hanging wall of ABF shows thick massive yellowish medium-fine sand overlain by m thick laminated sequence of siltysand and clay. This suggests change in depositional environment from fluvial to fluvial-marine or tidal environment (high sea-level during yr?). Trench at Vigukot revealed prominent sand-sheets at three levels indicative of 3 major liquefaction events, triggered by near source earthquakes, the latest event probably be the 1819 Allah Bund. Preliminary OSL ages of the sediments dated from the sand blow, soft sediment deformational structures, faulted sedimentary units from the trenches excavated on the hanging wall and across the Allah Bund Fault suggests occurrence of at least 2-3 events during ka, with the most recent event during 2.0 ka January, 2011

151 MISCELLANEOUS M_P1 Specific Yield-Water Level Fluctuation Method an Effective Tool for Quantitave Evaluation of Groundwater Resource A Case Study Syed Zaheer Hasan (Gujarat Energy Research and Management Institute, 203, IT Tower-1, Infocity, Gandhinagar , Gujarat, India. India. and M. Yusuf Farooqui (Gujarat State Petroleum Corporation Ltd., GSPC Bhavan, 3rd Floor, North Wing, Sector-11, Gandhinagar , Gujarat, India. The area under study, Kasganj sub-division, district Etah, Uttar Pradesh, represents a part of Ganga- Kali interfluves characterized generally by a flat topography barring some uplands and low valleys. Covering an area of 1175 sq. km, the area falls under the sub-tropical climatic zone of India where the rainfall forms the principal source of groundwater recharge besides, the seepage from canals and irrigation return flow. The mean annual rainfall in the region is 755mm. The pre and post-monsoon depth to water level and fluctuation maps show a wide variation over the entire region corresponding to the surface topography and lithological control respectively. The Quaternary alluvium unconformably rests over Neogene sediments, which is unconformably underlain by the lower Bhander Limestone and continues upto the Bundelkhand Granite. The study shows that the groundwater recharge through canal seepage is 71.23MCM whereas; through irrigation return flow it is 45.77MCM and the monsoon recharge is MCM. The net annual recharge is MCM and the net draft is MCM thus, leaving a balance of 95.70MCM as utilizable resource for future development. The stage of groundwater development is 58.56%, which shows that the area falls under the safe category. Keywords: Groundwater development, groundwater recharge, canal seepage, irrigation return flow, monsoon recharge, groundwater draft and groundwater resource evaluation M_P2 Environmental studies using Electrical Resistivity Method Sunita Devi & Rupal Malik (Institute of Seismological Research, Gandhinagar, India. E- mail: Ground water is one of the basic needs of the human beings for their survival on the earth. With the development, it is being polluted because of the addition of the chemicals into seas, rivers & lakes. The impact of pollutants like solid & liquid wastes produced by different source (domestic & industrial), pesticides used in agriculture on our environment can be studied by resistivity survey. We have used the Electrical method for this purpose. The objective was the environmental studies in the area. For this purpose, the data was acquired in the Kurukshetra University, in Haryana near the canal & at dump site. The data was acquired using Wenner configuration using 2m electrode spacing. After collecting, the data was interpreted using RES2div software. The resistivity values came out to be of the order of ohm-m. The resistivity values were low near the surface & up to depth 4.0 m. these low values were due to seepage from canal thereby increasing moisture content, leading to low value of resistivity. Near the dump site, the survey was done using wenner configuration & the resistivity values vary from 14.0 to ohm-m. the high values are due to dryness in the area & broken building material. In the near surface the resistivity values were low in the range 10.8 to 16.4 ohm-m. Thus the resistivity method helps in the environmental studies January,

152 SPECIAL LECTURES ISES Lecture Program on Study of Earthquake Precursors in India Harsh Gupta (Panikkar Professor, National Geophysical Research Institute,(Council of Scientific and Industrial Research)Hyderabad , India.) A National Task Force for earthquake precursory studies was set up by the Department of Science and Technology, Government of India to take stock of the efforts and the progress made so far in the area of earthquake precursory studies and formulation of a focused program, relevant to Indian Context. A series of meetings were held and the global effort on study of earthquake precursors was examined. A note was made of the precursors observed by the Indian scientists, and success in medium term forecast in the North- East India region, and short term forecasts in the Koyna region of artificial water reservoir triggered earthquakes. Keeping in mind the large Indian Territory and that Himalayan region is particularly vulnerable to frequent damaging earthquakes, the following approach is suggested: 1. Identify a few areas (4 to 5) where a few precursors (such as swarms and the following quiescence) have been observed and there is a good probability of an earthquake (Me 6) to occur, particularly in the Himalayan region hubs are proposed for concentrated observations of all possible precursors by concerned agencies/laboratories/universities. These are: a. RRL, Jorhat for NE Himalaya b. WIHG, Dehradun for NW Himalaya c. IMD, Central Himalaya d. NGRI for Koyna and one or two other locations in Himalaya 3. In these identified areas concerted efforts by various partners to monitor all possible precursors. 4. Operate multi parametric observatories at a few selected locations. 5. Look into the possibility of setting up a 15 to 20 element SODAR system to cover the entire (2000km) range of Himalaya to monitor temperature in the 5-6 km layer of the atmosphere for monitoring possible thermal anomalies. 6. Solicit and develop satellite projects for monitoring the precursors. 7. Meet frequently (every 3 months) to monitor the progress. It is also suggested to prepare earthquake scenarios, if the past damaging earthquakes repeat. An additional issue is to set up rapid forecast of anticipated accelerations soon after a major earthquake occurs in the vicinity of a metropolis, particularly New Delhi, the capital of India which lies in the vicinity of the Himalayan earthquake belt. Special - 1 Shailesh Nayak (Secretary MoES, Govt. of India) Special - 2 India s Tsunami Warning System: A Success Story Harsh Gupta (Panikkar Professor, National Geophysical Research Institute,(Council of Scientific & Industrial Research) Hyderabad , INDIA. The recent Indian Ocean Tsunami (December 26, 2004), is now established to be the strongest in the world over the past 40 years. It resulted in devastations amounting to national calamities in several parts of the Indian Ocean. As compared to the most severe Tsunamis of the past, the loss of lives in the Indian Ocean Tsunami has been higher by an order of magnitude, thereby calling for development of Tsunami Warning System on a warfooting. The coastal population being the victims of storm surges and tsunami, it is obvious that the systems for their mitigation have several commonalities (in terms of observational network, data base on bathymetry and coastal topography, data January, 2011

153 communication, dissemination of warnings, training and education, operational practices) and hence it is prudent and cost-effective to address them together. India planned for development of an integrated mitigation system for the oceanogenic disasters viz. Tsunami and storm surges in the northern part of Indian Ocean region with an ultimate goal to save lives and property. The design of the System is based on end-to-end principle, involving i) mean real time estimate of earthquake parameters, ii) assessment whether a tsunami has been indeed generated through deployment of ocean bottom pressure sensors and tide guages, iii) numerical modelling for tsunami, storm surges with all associated data inputs, iv) generation of coastal inundation and vulnerability maps, v) development of Tsunami Warning Centre at INCOIS, Hyderabad and its operation on 24x7 basis for generation of timely advisories for implementation, and vi) capacity building, education, and training for all stakeholders. The Project has been implemented by the Department of Ocean Development (now Ministry of Earth Sciences) through its Institutions, with active participation from Department of Science and Technology, Department of Space, Council of Scientific and Industrial Research, and University departments. The planning of project started in January By March 2005 all the details were worked out and it was estimated that it would be operational by September This deadline has been successfully met, and system tested during the occurrence of tsunamigenic earthquake on September 12 & 13, Today, this is the best system operating any where in the world. Special - 3 Time-varying Tsunami Characteristics in Wavelet Domain Ashutosh Chamoli (E- mail: V. Swaroopa Rani, Kirti Srivastava, D. Srinagesh and V.P. Dimri (National Geophysical Research Institute, Hyderabad , India.(Council of Scientific and Industrial Research)) Wavelet theory provides different methodologies to understand the signal behavior and interpretation in space scale domain. In this domain, the time-varying signals can be analysed in a unique framework and the signatures in wavelet domain give optimum timefrequency information. In this work, the seismograms of different earthquakes are studied using wavelet analysis and characterized for tsunamigenesis. The frequency content of the earthquakes is interpreted in terms of rupture duration and slip of the earthquake. The methodology is tested on the earthquakes mainly from Andaman-Sumatra region and other important earthquakes. The wavelet domain analysis provides a diagnostic method to understand the seismogram characteristics. Special - 4 Making of Probabilistic Seismic Hazard Map of India for the Bureau of Indian Standards B.K. Rastogi, RBS Yadav, Babita Sharma and Vikas Kumar (Institute of Seismological Research, Raisan, Gandhinagar , India Seismic Hazard in term of engineering design is generally defined as the predicted level of ground acceleration which would be exceeded with 10% probability at the site which is under consideration due to the occurrence of earthquake in the region, in next 50 years. This corresponds to a return period of 475 years meaning in next so many years, the estimated acceleration can be expected. It is also called Operating Basis Earthquake (OBE). Different probabilities and return periods are also considered some times. The acceleration exceedance map with 2% probability in 50 years (return period 2375 years) is called Maximum Credible Earthquake (MCE). Probabilistic Seismic Hazard Analysis (PSHA) involves three steps: 1) Specification of the seismic-hazard source models 2) Specification of the ground motion models (attenuation relationships), and 3) Probabilistic calculation January,

154 The input parameters that are needed for performing a Probabilistic Seismic Hazard Analysis (PSHA) following the Cornell approach (Cornell, 1968; Reiter, 1990) are: A seismotectonic source model, which defines fault or areal zones of equal seismic potential. The definition of source zones relies to a large degree on expert judgment, which is based on the assessment of the seismotectonic framework, on past seismicity, and on considerations regarding the temporal and spatial stationarity of earthquake activity. An earthquake catalog, which is used to derive recurrence rates and to estimate the maximum possible earthquake for each source zone. A predictive ground-motion model (PGMM), which describes the attenuation of amplitudes (acceleration, velocities) as a function of distance as well as the scaling of ground-motion as a function of magnitude. The Indian subcontinent region bound by N and E has been considered for the preparation of probabilistic seismic hazard map of India as task given by Bureau of Indian Standards (BIS). The study region consists of India including Andaman-Nicobar islands and also Pakistan, Hindu Kush, Karakoram, Tibet and Burma. Based on the seismicity distribution and tectonic features, 31 potential seismic source zones were delineated. The seismotectonic characteristics of these source zones have been explained. A seismicity database has been prepared for the period AD 180 to 2008 containing earthquakes, using all existing catalogues. The prepared seismicity database has been homogenized for moment magnitude (M w ) with the help of various empirical relationships developed among different magnitude scales (M L, M s, m b and M w ). The 50.14% earthquakes (foreshocks and aftershocks) being dependent have been removed from the entire catalogue using the method developed by Uhrhammer (1986). In this method, initially a visual analysis of earthquake catalogue is necessary to identify the seismic cluster. A spatial and temporal windowing method is applied to identify the aftershocks and foreshocks from the seismic clusters. The spatial extension (L) of the cluster of aftershocks and foreshocks is estimated using the equation Log L = a * M +, where, a and b are the coefficients of regression equation. The spatial window has a circular shape with a radius equal to L/2 and centered on the main event. The duration (T) of the cluster of aftershocks and foreshocks is counted from the first event in the sequence and expressed as a function of magnitude M through the equation Log T = c * M + d. where c and d are the coefficients of regression equation. All events (foreshocks and aftershocks) with epicenters falling within the defined two windows are removed. The cut-off magnitude (threshold magnitude or magnitude of completeness, Mc) for this seismicity database is estimated as M w 4.5 for interplate (Himalayan seismic belt) region and 4.1±0.17 for intraplate (Peninsular India) region. The completeness periods for different magnitude ranges are also estimated. It is observed that in Peninsular India events with magnitude are complete for 80 years, while events for Mw > 4.5 are complete for 200 years. Along Himalayan plate boundary regions catalogue is complete for 40 years for magnitude M w ; 80 years for M w ; 100 years for M w ; and 200 years for M w M w >7.0. Using the clean catalog, the seismic hazard parameters a-value (defining seismicity level), b- value (defining number of large earthquakes expected w.r.t. smaller ones), M max (The maximum magnitude was estimated from past seismicity for each of zones separately) and return period were estimated by a computer program written by A. Kijko, which goes as inputs to hazard computation. The maximum likelihood estimation of earthquake hazard parameters (maximum magnitude M max earthquake activity rate ë and b parameter in Gutenberg-Richter equation) is extended to the case of mixed data containing large historical events (extreme catalogue) and recent complete instrumental data (complete catalogue). Therefore January, 2011

155 to find these hazard parameters we divide the earthquake catalogue into two parts, namely, extreme catalogue and complete part of catalogue. The extreme part of catalogue, extended to allow for varying time intervals from which maximum magnitude are selected. Assuming that this part of the catalogue contains only the largest seismic events, and having the possibility of dividing the catalogue into time intervals of different lengths, the complete part of catalogue rejects the macroseismic observations that are incomplete and uses complete part of catalogue. In Kijko approach it is possible to combine the information contained in the macroseismic part of catalogue with that contained in the more complete parts of catalogue. Thus, to determine the seismic hazard parameters (maximum magnitude M max earthquake activity rate ë, b value and return period) of Indian region we use extreme as well as complete part of catalogue, separately as the input of Kijko computer program. For example, for Zone1 we divide its earthquake data into extreme and complete part. The earthquake data for this zone is from 1912 to From 1912 to 1963 the earthquake data is not complete so we take it as extreme part of catalogue. From 1964 to 2008 the earthquake data is completely recorded. Thus we take this part of catalogue as complete one. The output of this contains b-value, beta, activity rate, and return period. After finding the all hazard parameters, the next step is to prepare a Seismic Hazard map, for this we use probabilistic hazard assessment approach of Esteva- Cornell, to determining the peak ground acceleration (PGA), which were computed using CRISIS2007 software for 10% probability of exceedance in 50 years, for Indian region, on a grid of points spaced by an angular distance of 1.0 degrees both in N-S and in E-W direction. Our basic assumption in the application of CRISIS2007 code is a Poissonian model of seismic event time recurrence. An attenuation relationship is used to provide probabilistic estimates of PGA expected at a given distance for an earthquake of given magnitude: at this regard we adopted the relationship obtained by Abrahamson & Silva (1997), Youngs et al (1997) and SEA99 (1997) January, 2011 Abrahamson & Silva (1997) derived attenuation relation for the average horizontal and vertical component for shallow earthquakes in active tectonic regions as given below: log(pga)= a 1 + a 2 ( M-6.4) - a 3 (8.5-M) 2 + { a 4 + a 5 (M-6.4)}LN(R) where, a 1, a 2, a 3, a 4, and a 5 are constants, M stands for given magnitude and R is the closest distance to the rupture plane in km. In Youngs et al. (1997), attenuation relation for peak ground acceleration for subduction zone earthquake is determined. The attenuation relation given as, log (PGA) ij = C 1 * + C 2 M i + C 3 * ln[(r) ij + exp{c 4 * - (C 2 /C 3 * )M i }] + C 5 Z ss + C 8 Z t + C 9 H i + ç i + å ij ; C 4 * = C 4 + C 7 Z s C 1 * = C 1 + C 3 C 4 - C 3 * C 4 * ; C 3 * = C 3 + C 6 Z s where i is earthquake index, j is the recording station index for the ith event, M is moment magnitude, R is the closest distance to the rupture plane in km, H is focal depth, C k, k=1 to k=10 are coefficients determined by regression analysis, Z ss indicates shallow stiff, ç i (inter-event component representing earthquake to earthquake variability of ground motions) and å ij (intra-event component representing earthquake variability of ground motions) are error terms, Z t indicates source type (0 for interface events and 1 for intraslab) While in SEA99 (1997), attenuation relation is derived for hard rocks and for soil. Based on seismotectonic features of our 31 seismic zones, we applied this attenuation relation to these seismic zones. For zones 1 to 7, zones 9 to 13 and zones 16 to 18, Youngs et al. attenuation is applied. For zones 8, 14, 15, and 22, Abrahamson and Silva attenuation model is applied. And SEA99 attenuation model is applied for zones 21 and zone 23 to 31. Besides these attenuation relation as input for hazard computation in CRISIS2007, we take threshold magnitude (i.e. minimum magnitude), upper bound magnitude (maximum magnitude), and all seismic hazard parameters (Beta â, earthquake activity rate ë and b value) for each seismic zone as an input. The 125

156 Fig. Seismic Hazard Map of India with Return Period of 475 years i.e. 10% probability in 50 years. The value of PGA is expressed in terms of gal. hazard map for 10% probability of exceedance in 50 years (Fig.) shows that Hindu Kush region have high hazard level of order 3.989E+02 gal, followed by Northeast and Burmese arc where hazard level is 3.20E+02 gal, the northwest Himalaya shows the hazard level up to an order of E+02 gal, whereas Tibetan plateau region have hazard level of order 1.90E+02 gal. In Indian shield region the order of hazard level is on average 4.25E+01 gal whereas some areas like Kachchh where hazard level is up to 1.20E+02 gal and Koyna having hazard of order 1.513E+02 gal. The Andaman-Nicobar region also shows the high level of hazard of order 3.125E+02 gal. Special - 5 NEW PROBABILISTIC SEISMIC HAZARD MAP OF INDIA R. N. Iyengar (Centre for Disaster Mitigation, Jain University, Bangalore-Kanakapura Road, Jakkasandra In this talk the new PSHA map of India developed for NDMA, Govt. of India will be presented. The talk highlights how the source, path, site paradigm has been used to estimate surface level hazard at hard rock sites (A-type: Vs > 1.5 km/s). All known data about past earthquakes and mapped faults are considered to characterize the seismic activity. Based on the tectonic setting of the country and disposition of faults thirty-two source zones are identified. An earthquake catalogue (M w >4) from the remote past January, 2011

157 till the end of year 2008 is prepared with discussion on issues related to completeness and recurrence relations. The country is structured into seven geological provinces with differing quality factors. Finite fault stochastic source mechanism model of Boore is used to develop new strong motion attenuation relations for the above seven regions. Validation of the empirical relations is presented wherever possible with available strong motion data. Standard PSHA has been carried out covering the whole country on a grid size of x Well established probabilistic analysis procedure is adopted to compute the prevalent hazard in terms of peak ground acceleration (PGA), short period and long period spectral accelerations for return periods of 500, 2500 years. Contours of PGA values for 5000 and year return periods are also mapped. The results presented can be directly used on A- type rock sites. For other site types, corrections have to be applied in terms of either modifying factors prescribed in standard codes (IBC-2009) or by carrying out necessary soil amplification analysis based on local geotechnical data. Application the PSHA results is illustrated by working out the design response spectra as per IBC-2009 for the four metropolitan cities, Delhi, Mumbai, Kolkata and Chennai. Special - 6 RECOMMENDATIONS FOR EARTHQUAKE SAFETY AND RETROFITTING IN GUJARAT Padmashree Dr. Anand S. Arya (FNA, FNAE; Ex-National Seismic Advisor MHA, GoI-UNDP Professor Emeritus of Earthquake Engineering, IIT- Roorkee, India s high earthquake risk and vulnerability is clear from the fact that about 59 per cent of India s land area could face moderate to severe earthquakes in seismic III, VI and V. During the period 1990to 2006, more than 23,000 lives were lost in India due to 6 major earthquakes, which also caused enormous damage to buildings and public infrastructure. These earthquakes include the Uttarkashi earthquake of 1991, the Latur earthquake of 1993, the Jabalpur earthquake of 1997, and the Chamoli earthquake of 1999, followed by the Bhuj earthquake of 26 January 2001 and the Jammu & Kashmir earthquake of 8 October 2005.The occurrence of several devastating earthquakes even in Zone III area indicates that the built environment in the country is extremely fragile. All these major earthquakes established that the casualties were caused primarily due to the collapse of buildings. However, similar high intensity earthquakes in the United States, Japan, etc., do not lead to such enormous loss of lives, as the structures in these countries are built with structural mitigation measures and earthquake-resistant features. This emphasizes the need for strict compliance of town planning bye-laws and earthquake-resistant building codes in India. For achieving earthquake safety, there is a need to undertake reduction of earthquake risk before the next earthquake strikes. Disaster risk reduction and its mainstreaming into all development activities has become a subject of utmost importance. The measures required to reduce direct, in direct and intangible disaster losses, will have to cover technical, social or economic action, to be taken by the various stakeholders. Two aspects of the disaster reduction strategy are i) mitigation involving measures for reducing the impact or effect of the occurrence of an earthquake, and ii) preparedness meaning a state of readiness to deal with a threatening earthquake situation and the effects thereof. These measures need to be mainstreamed into the development policy and practice so that it becomes normal practice, fully institutionalized in the State. The paper will attempt to present the actions to be taken by the state and various stakeholders namely i) the owners of the buildings such the state government, various undertakings, banks, businesses, housing boards, etc.: the various executing departments such as PWDs, Development Authorities, health and education departments, cantonments, police and industries, etc. The Local Body Authorities namely, the corporations, municipal councils, nagar panchayat and rural panchayats must play their regulating and monitoring roles. These January,

158 operations will requires capacity buildings at various levels in which the universities, technical and professional colleges and training centres will have to play critical role. The funding organizations like banks insurance etc. must develop techno-financial regulations so that all developments funded by these organizations are designed and constructed to remain safe in the next earthquake. Mainstreaming of disaster risk reduction will go a long way to minimize adverse impact of future earthquakes in the State Special - 7 S K Jain CMD, NPCIL, Mumbai Nuclear power in India is poised for a large expansion, based both on indigenous technologies and with foreign cooperation. In the next two decades, an installed capacity of MW is planned to be reached from the present 4780 MW. This capacity is planned to be reached by setting up about 40,000 MW of Light Water Reactors (LWR) in technical cooperation with foreign countries and the remaining based on indigenous Pressurised Heavy Water Reactors (PHWR), Fast Breeder Reactors (FBR). The LWRs based on foreign cooperation are planned to be indigenized progressively. There are also plans to develop and deploy indigenous LWRs Safety is of paramount importance in nuclear power, the motto being safety first, generation next. Safety against external natural events, particularly earthquakes is accorded highest priority in nuclear power plants, in siting, design, construction and operation. Structures, systems and equipment are designed and qualified for possible earthquake loads to ensure their safe and reliable performance during an earthquake. Special - 8 Structure, Tectonics & Active Faults of Kutch Rift Basin, Gujarat, Western India S. K. Biswas (Formerly: Director, KD Malviya Institute Petroleum Exploration, Dehradun Flat No. 201, C-Block, ISM House Thakur village, Kandivili (E) Mumbai Ph: , , The Kutch basin is a western margin pericratonic rift basin of India. The rift is bound by Nagar Parkar uplift in the north and Kathiawar uplift (Saurashtra horst) in the south respectively along Nagar Parkar and North Kathiawar faults (NPF & NKF). The rift is styled by three main uplifts along three master faults, (from north to south) Island Belt, Kutch Mainland and Wagad uplifts, with intervening grabens and half-grabens. The uplifts are upthrust basement blocks tilted along sub-vertical faults with initial normal separation. The NKF is the principal master fault along which the rift subsided most. The structure is thus styled by tilted blocks and halfgrabens within a south tilted asymmetric rift basin. Blanketing sediments over the basement drape over the tilted edges of the upthrusts as marginal flexures. The flexures are narrow deformation zones along master faults enclosing complicated folds, locally much faulted and intruded by igneous rocks. In the western part the uplifts are tilted to the south with flexures draped over the faulted up northern edges. In the eastern part a large uplift, Wagad Uplift, occurs between the Mainland and Island Belt uplifts. It is tilted opposite to the north with a narrow deformation zone along the faulted southern edge. The backslope ends up against Bela horst of the Island Belt uplift. A subsurface basement ridge Median High, crosses the basin at right angle to its axis in the middle. Acting as a hinge it divides the basin into a deeper western part and a shallower and more tectonised eastern part. The rift is terminated in the east against a transverse subsurface basement ridge, Radhanpur Arch, which is the western shoulder of the adjacent N-S oriented Cambay rift. To the west the rift merges with offshore shelf. The Kutch basin is the earliest pericratonic rift basin to form in the western margin of the Indian craton during the Late Triassic break up of Gondwanaland. The rift evolution with syn-rift sedimentation continued through Jurassic till Early Cretaceous as Indian plate separated from Africa and drifted northward along an anticlockwise path. The rift expanded from north to south by successive reactivation of primordial faults of Mid-Proterozoic January, 2011

159 Delhi fold belt. The faults strike E-W but eastward the strike swings to NE-SW merging with the Delhi- Aravalli strike. The rifting was aborted by the trailing edge uplift during Late Cretaceous pre-collision stage of the Indian plate. The uplift caused structural inversion during rift-drift transition stage when most of the uplifts with drape folding over the edges came into existence by upthrusting along the master faults. The motion during the drift stage of the plate induced horizontal stress and the near vertical normal faults, which were reactivated as reverse faults during initiation inversion cycle, became strike-slip faults involving divergent oblique-slip movements. The present structural style evolved by right lateral slip, which shifted the uplifts progressively eastward relative to each other from south to north. This resulted in the present en echelon positioning of the uplifts with respect to Kutch Mainland uplift. The strike slip related structuring modified the linear flexures breaking them into individual folds at the restraining and releasing bends. Narrow deformation zones complicated by conjugate reidal faults formed along the master faults modifying the initial drape folds. Syntectonic intrusions further modified the structures. Igneous rocks extensively intruded the Mesozoic sediments during rifting and post rift hotspot related Deccan volcanicity. Studies on the intrusive bodies and seismological data suggest the presence of an ultramafic magmatic body close to the crust-mantle boundary. Inversion continues during post-collision compressive regime of the Indian plate and the Kutch rift basin has become a shear zone with transpressional strikeslip movements along the active sub-parallel rift faults. This is evident from neotectonic movements along these faults that are responsible for the present first order geomorphic features. In the current tectonic cycle under NNE-SSW compressive stresses the KMF/ SWF and KHF are the most active faults as evident from the concentration of aftershock hypocenters. Pulses of movement along these faults are responsible for generation of new fault fractures within the respective deformation zones. These new fractures are propagating through the recent piedmont and scarp-fan sediments in the January, 2011 frontal zones of the thrusts as seen in the trenches dug close to KMF and KHF and in GPR surveys. The pulses are also destabilizing the loose gravelly sediments causing gravity sliding seen as low-angle to sub-horizontal fractures associated with the faultgenerated fractures. The morphotectonic features also indicate Quaternary uplift along the above mentioned faults. During the present compressive stage the Radhanpur arch acts as a stress barrier for eastward movements along the principal deformation zones (PDZ). This is creating additional strain in this part of the basin between the arch and the Median High. The Kutch Mainland Fault (KMF) along the rift axis becomes the active principal fault. Towards the eastern end of the Mainland uplift the right lateral KMF, becomes South Wagad Fault (SWF) by left stepping with an overlap in the region between Samakhali and Lakdiya. This overstep zone Samakhiali-Lakadiya graben - is a convergent transfer zone undergoing transpressional stress in the strained eastern part of the basin. This is the most strained part of the basin. Expectedly, this is the most favoured site for rupture nucleation. The occurrence of closely spaced epicenters of two major earthquakes viz., 1956 Anjar (Ms 6.1) and 2001 Bhuj (Ms.7.9), in this zone and concentration of aftershock hypocenters around it validate this conclusion. The sub-vertical SWF is expected to flatten with depth towards the south in the mid-crustal region and merge with a listric link fault, presumably the northern rift margin fault, NPF. Thus, SWF is expected to dip about 60 0 S in the mid crustal region. The similar pattern is indicated by the distribution of the aftershock hypocentres. The aftershock data suggest a reverse slip on a fault plane dipping 60 o south as the causative fault. SWF zone, therefore, seems to be the causative fault of the Bhuj as well as Anjar earthquakes. The curvature of the fault at a depth of 20+ km, close to the ultramafic magmatic body at the base of the lower crust appears to be the zone of earthquake nucleation. Presumably, the fluid released by the serpentinisation of the ultramafic body aids the slippage along this causative fault. Based on this and the detailed depth wise analysis of aftershock data, a conceptual domino-listric model of Kutch rift is presented here. 129

160 Special - 9 A TESTABLE MODEL FOR INTRAPLATE EARTHQUAKES Pradeep Talwani ((Retired), Dept. of Earth and Ocean Sciences, University of South Carolina, Columbia, SC, 29208, USA. Globally, more than 98% of the total seismic moment release associated with intraplate earthquakes (IPE) occurs in former rifts and taphrogens (Schulte and Mooney, 2001). The seismicity occurs at stress concentrators in both shallow and deeper crust in response to the ambient compressional stress field (Gangopadhyay and Talwani, 2003). At many locations of IPE, the stress field is further modified by local stress perturbations (e.g. due to glacial rebound, sedimentary deposition etc., Talwani and Rajendran, 1990). Weakening agents, such as the presence of fluids at hypocentral depths further influence the seismogenesis of IPE. Mooney and Ritsema (2010) have shown that these rifted basins are associated with a weaker lower crust, mappable by S-wave seismic tomography. Modeling results have shown that when rifted sedimentary basins which had been formed under extension, with a priori weaknesses, are inverted under compression, the results are weak conjugate and boundary faults with up-welled lower crust, identified as rift pillows These characteristic features of stress inversion are associated with local (~100s surface area) elevated strain rates. These observations and modeling results suggest the following testable model. Major IPE occur in reactivated rifted basins, with conjugate and boundary faults and an up-welled lower crust. (The precise geometry and seismic potential of each site depends on its tectonic history and geometry after stress inversion). These features are sites of LOCAL stress concentrations and elevated strain rates, and potential IPE. I will illustrate these ideas with data from Kutch and Sea of Japan earthquakes. To test this model and to predict potential locations of IPE, S-wave tomography can be used to define the weaker lower crust associated with rifted basins, and dense, continuous GPS observations can be used to identify LOCAL pockets of elevated strain rates; and seismicity and geophysical observations can be used to identify stress concentrators and locations of IPE. Special - 10 SPACE INPUTS IN DISASTER MONITORING, MITIGATION AND EARLY WARNING R.R. Navalgund and A.S. Rajawat (Space Applications Centre, Indian Space Research Organisation, Ahmedabad INDIA Natural disasters are events, which are caused by purely natural phenomena and bring damage to human societies (such as earthquakes, volcanic eruptions, cyclones, spread of epidemics, asteroid/ meteorite impacts etc.). Natural disasters are inevitable and in general difficult to predict. Humaninduced disasters are natural disasters that are accelerated/ aggravated by human influence (such as landslides, forest fire, floods, land subsidence, desertification, coastal erosion etc.). Human made disasters are events, which are caused by human activities (such as atmospheric pollution, industrial, chemical accidents, major armed conflicts, nuclear accidents, oil spill etc.). Natural disasters may occur at global, regional or local scale. Time and spatial extent of disasters may vary e.g., earthquake may destroy a large area in few seconds, landslide may damage a small area in few minutes, floods may damage a large area in few hours to days where as drought may damage a large area in few weeks to months. Population growth and occupation requirements force people to live in areas vulnerable to natural hazards, especially in developing and underdeveloped countries. India has been traditionally vulnerable to natural hazards on account of its unique geo-climatic settings. It is frequently affected by disasters such as tropical cyclones, floods, drought, earthquakes, landslides, forest fires, oil slicks and occasionally tsunami. Besides slow yet significant hazards like coastal erosion, desertification, land degradation, glacial retreat and sea level rise are another threat our country faces. Disaster management is the key issue and the country s scientific and technological achievements January, 2011

161 have a major role to play in it. Disaster Management aims to minimize loss of life, property and environment. Space provides scientific and technological ways and means in all stages of Disaster Management. Disaster Management involves effective Preparedness, Response, Rehabilitation, Reconstruction and Mitigation for a specific disaster and improvement at each component level with recurrence of that particular disaster. Communication satellites help in early warning and relief mobilization. Earth observation satellites provide reliable database for disaster prevention, mitigation and preparedness programmes. Geographic Information System (GIS) provides additional tool to integrate large spatial and aspatial geo-referenced data sets for improved disaster management solutions. A synergy of Earth Observation, GIS and communication technology is playing a major role in effective disaster management. Realizing the role of space technology in various components of a disaster management cycle, Department of Space, Indian Space Research Organisation (ISRO) has launched Disaster Management Support (DMS) Programme as one of its key programs. Constellation of Indian satellite Series (IRS, Resourcesat, Cartosat, Oceansat, INSAT, GSAT) provides quick and reliable services in all phases of disaster management. The DMS program focuses on integrating the space technology inputs and services, on a reliable and timely basis through various units of ISRO. Space based inputs are operationally provided to various state and central user agencies by Decision Support Centre of National Remote Sensing Centre (NRSC), Hyderabad for various natural disasters in particular for floods, drought and forest fire. Space Applications Centre, Ahmedabad provides R&D support to DMS Programme by identifying and carrying out pilot studies related to use of space technology for early warning of various natural disasters, development of Airborne DM-SAR and satellite based emergency communication systems. Indian Institute of Remote Sensing, Dehradun supports capacity building besides R&D for various natural geo-hazards. Some of the major disasters occurring frequently in India and use of space technology in disaster monitoring, mitigation and early warning are discussed in this paper. The tropical cyclone constitutes one of the most destructive natural disasters over the coastal areas, which bear the brunt of the strong surface winds, squalls and flooding from storm rainfall and storm surge as well as ocean wave action. The tropical cyclone forecasting involves: Geolocation (Locating the position (centre) of the cyclone); Track change detection; Intensity Estimation; Intensity change detection. In all these aspects, satellites have been effectively used. Real-time cyclone track prediction algorithms using INSAT data have been developed. All the cyclones in the Indian Ocean during were tracked and predicted in real-time with a lead time of 48 h. Real-time track prediction for tropical cyclones GONU, SIDR, AKASH and NARGIS are some of the examples. 24 hour track prediction error ranges from km for different algorithms and 5-day track prediction error is < 250 km. In addition, an Automated Intensity Estimation Algorithm was developed using Multichannel Microwave data, JTWC Intensity analysis (maximum sustained wind) and all global cyclones for the period The accuracy of developed algorithm is ~11 kt, which is at par with the accuracy of existing methods globally. As most of the major cities are located near the coast, tidal floods are serious disasters. Remote sensing data especially RADAR images are one of the powerful tools to map the inundated areas even when clouds are present. Satellite data is operationally analyzed for early warning of drought. Early warning of drought is based on monitoring vegetation status using National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) data for the entire country and IRS WiFS/ AWiFS data for at district level. At present, fourteen States of the country- Andhra Pradesh, Bihar, Chhatisgarh, Gujarat, Haryana, Jharkhand, Karnataka, Maharashtra, Madhya Pradesh, Maharashtra, Orissa, Rajasthan, Tamil Nadu, Uttarakhand and Uttar Pradesh are covered and bulletins giving the district-wise status are issued from August to October. These bulletins are sent to Dept. of Agriculture and cooperation, State Agricultural Department and Relief Commissioner for implementing relief measures January,

162 Remote sensing is useful in identifying precursors to earthquakes such as sudden rise in land surface temperature, sudden changes in gravity anomaly and in assessing damage to infrastructures and geomorphic changes caused by the earthquake in near real time. Early warning research through identification of precursors to earthquakes such as sudden rise in land surface temperature (NOAA AVHRR data), have been carried out in hindcast mode for seismically active region of Kachchh, Gujarat. In addition, geophysical (gravity/magnetic) studies have been done in seismically active regions of Kachchh and Andaman & Nicobar island regions. Differential SAR interferometry techniques are being explored for early detection of surface deformation of the crust (ALOS/ENVISAT/ERS- 1/2 data) for seismically active zones such as parts of Kachchh, Gujarat and Himalayan regions. Remote sensing and GIS techniques are used in inventory and monitoring of landslides and landslide hazard zonation. Methodology for Landslide hazard zonation has been developed by integrating information on lithology, structure, geomorphology, slope, aspect, land use/land cover, and drainage for some of the most landslide prone regions of the Himalayan Ranges. Efforts are in progress towards developing rainfall threshold based early warning models of landslides in Garhwal and Sikkim Himalayas. Remote sensing data (IRS-1C/1D, MODIS, ASTER etc.) along with GIS techniques are being used to provide information on Forest Fire detection and monitoring; Post fire damage assessment, fire Scar / burnt area mapping; Forest Fire prone / risk area mapping, and Planning the recovery of forest stand and mitigation. Remote sensing data helps in mapping desertification processes/indicators and their severity. Desertification status mapping of entire country using multitemporal Resourcesat-1 AWiFS data on 1:500, 000 scale has been carried out. Method for early warning of desertification was developed based on Desertification Vulnerability Index (DVI). High and medium resolution and multi-temporal remote sensing data has proved useful for assessing the damage caused by Tsunamis. Besides, this tsunami warning system has become operational at INCOIS, Hyderabad using INSAT based communication network among seismic stations, tide gauges, data buoys with pressure sensors. Coastal erosion has caused and continues to cause property damage, and large sums of money are spent to control it. Shoreline change maps for the entire Indian coastline have been prepared using remote sensing data at 1: 50, 000 scale and at 1:25,000 scale. Vulnerable zones for coastal erosion have been identified. It is necessary to identify areas, which may be affected by sea level rise, so that remedial measures can be planned. An approach has been developed to understand coastal processes using Indian Remote Sensing Satellite data for carrying out Coastal Vulnerability Index (CVI) based assessment of the coastal zone of Andhra Pradesh, Tamilnadu and Gujarat states. Disaster is a global phenomenon. Any disaster that strikes does not restrict itself to a country s administrative boundary. Even if its effect is limited to a particular country, it becomes a global concern for response and relief. Hence, it is essential to have a network of various international organizations working towards disaster management, more particularly in the field of utilization of space technology for disaster management. The activities of international organizations such as International Charter on Space and Major Disasters Global Earth Observation System of Systems (GEOSS), UN-SPIDER, Sentinel Asia, GMES-SAFER, Disaster Monitoring Constellation etc. are noteworthy. Efforts are in progress to realize International cooperation to strengthen existing constellation of EO satellites for specific applications related to all phases of disaster management and in particular for early warning. Special - 11 Bhuj 2001 Earthquake Revisiting existing knowledge of structural behavior of traditional and new constructions, geological hazards of the Kutch region and the regime of seismic safety. Alpa Sheth 1 & V Thiruppugazh 2 ( 5 Seismic Advisor, Gujarat State Disaster Management Authority January, 2011

163 Additional Chief Executive Officer, Gujarat State Disaster Management Authority) The Bhuj Earthquake of 2001 brought to the forefront several knowledge gaps in our understanding of the seismicity of the region, expected behavior of structures in a region of such seismicity and the regime for ensuring structural safety of the built habitat under seismic loads. The paper discusses some of these issues such as Microzonation studies carried out in the Kutch region identified hitherto unknown levels of hazard. There is need to incorporate new-found hazards in our design process through upgradation of design codes. Traditional housing which had some seismic resistant features behaved better than some reinforced concrete frame structures. The Bhuj earthquake thus provided an occasion to review long-held views that reinforced concrete buildings were safer than traditional homes and made a case for confined masonry housing and other such systems. The earthquake identified the need for having indigenously grown mechanisms for seismic safety. International regimes of regulatory frameworks, implementation mechanisms and code compliance do not work effectively for safe housing strategies in regions with a strong sense of tradition and a long history of disregard to formal processes. Innovative strategies involving incentivization, sensitization and hand-holding are more effective to foster a culture of seismic safety than hard measures Special - 12 The Road to Seismic Safety Sudhir Jain, (Director IITgnr, Chandkheda, Ahmedabad, Special - 13 Bhuj earthquake and role of CEPT University in post disaster scenario Prof. V. R. Shah (H.O.D Structural Design department, CEPT University, Ahmedabad, India Gujarat, India had a large magnitude earthquake in CEPT University which is premier institute of learning for the built environment in the region played a major role for the post disaster work. Apart from carrying out a major rapid assessment survey of 5000 houses for the city of Ahmedabad which was used as model for other cities of Gujarat, the institute also took a lead role in post earthquake activities like reconstruction of villages and public buildings, conducting training programs for capacity building of architects, engineers and skilled workers. To involve its students into these activities, the institute re-oriented its academic program for the semester and the students got the first hand experience of architectural design of reconstruction, planning of villages and towns and participation in capacity building programmes, The presentation is on the activities an institute carried out in the event of disaster like major earthquake. The disaster like earthquakes are unfortunate events but how even those can be converted into an opportunities for the students and professional for learning and preparing them for the future was ably demonstrated by an institute. Institute collected the data of almost 5000 damaged houses which is now a rare and huge data bank for study of various aspects of behavior of modern urban structures January,

164 AUTHOR INDEX A Chaudhuri H Acharyya Anshuman... 18,20 Chauhan Mukesh... 82,89 Adwani Akash Chen C-H Aggarwal Sandeep... 6,14,46,75,76,77,78,89,107 Chhatre A.G ,104,105,107 Ahmad Bashir Choi1Jin-Hyuck Allameh-Zadeh Mostafa... 5 Chopra Sumer... 56,58,61,75,76,87,95 Alonso L. José Choubey V.M ,60 Anand S P County Vestige Guzhen Ansari K Choudhary Suryanshu Arora B.R ,44,60,85 Choudhury Pallabee... 93,95 Arora Yogesh D Ayra A S Da-quan YAO B Das J. D Bannerjee Chiranjib Dasgupta Sujit... 18,20 Bapat Arun Dastageer Faisal ,104,105 Barik Arijit Dattatrayam R.S ,52 Baruah Saurabh... 59,83 Devi Sunita Bayasgalan Amgalan Dhiman Gunjan Bellalem F Dikshit Onkar ,120 Berliet Ernelle Dimri Siddhart Bhakuni Chandra Dimri V.P ,123 Bhandari R. K Dumka R. K ,82,93,95 Bhanu Teja B Dutta Utpal Bhatia Gagan Dutta H.N Bhatt N.Y... 5 F Bhattacharya F ,120 Fathian A Bhattacharya S.N ,43,89 Faticoni Barbara Bhawal R.N ,104,105 Farooqui M. Yusuf Bhawsar S.D ,104,105 G Bihari Om Gadhavi M S Bilham Roger... 26, 62 Gahalaut Kalpna Bisht R S Gahalaut V.K ,91,95 Biswas Ankita Gamage Shantha S.N Biswas S. K... 82,96, 128 Gaur M.S Bobrovskii Alexander Gera B.S Bora K. Dipok... 20,83 Gerstoft Peter Bürgmann Roland... 91,92 Ghatpande M.A C Ghose D Carcolé E Giuliano F. Panza... 65,66,70 Celebi E Goktepe F Chadha R. K ,31 Gorshkov A Chandan Bora Goswami Rupen Chandrashekar D.V.... 8, 91,92 Gupta Sandeep January, 2011

165 Gupta A. K ,37,82 Gupta Harsh... 23,122 Gupta Sushil Gwal A.K H Hamdache M ,59,68 Hao Xiao-Guang Hasan Syed Zaheer Hasegawa Koichi Hassani B Hazarika Devajit Hazarika Pinki... 13,24 Helly Bruno Hough Susan Hu Xiao-Gang Hwang Cheinway I Ibrohim A Ingole S.M ,104,105 Irikura Kojiro... 58,61,63 Iyengar R N J Jain D.K Jain S K Jain Sudhir Jagad Mehul... 77,80 James Mr. Naveen Jan M. Qasim Jayangondapermal R Jin Kwangmin John Biju Joshi Vishwa... 89,107 Joshi A ,83,87 Joshi M Juroyov R K Kamra Leena Kaneko Fumio... 47,64 Kato Teruyuki Kayal J. R.... 2,16,59 Kazmer Miklos ,117 Khan Prosanta K Khandwe Santosh ,104,105 Kim Young-Seog ,115,119 Kolathayar Sreevalsa Korjenkov Andrey Kossobokov Vladimir G.... 3,4,64 Kothyari Ch.Girish... 29,82 Kouteva M Kumar Abhishek Kumar Deepak Kumar Devender Kumar Dinesh... 17,61,18,87,106 Kumar M.Ravi...13,24,72,83,84,86,88 Kumar Narendra... 86,60,20,44 Kumar Naresh... 20,44,60 Kumar Praveen... 69,84 Kumar Sushil... 34,80,81,64 Kumar Santosh... 6,106,14,46,57 Kumar Vikas... 82,123 Kushwah Vinod Kumar Kuyuk H.S L Lin S-J López Casado C Lee M M Madhusudana Rao K Mahendar N Mahendar N Mahmood A.S Maibam Sarda Majumdar T. J ,93,94,95 Malaviya K Malhotra Dr. Praveen K Malik Javed... 26,27,64,112,120 Malik Rupal Mamyrov Ernes Mandal Prantik... 2,3,6,16,21 Mandal H.S Manisha Matsuo Jun... 47,64 Mehdi Waseem Melana Deepanshu Mishra.O. P.... 7,15 Mishra Rajesh ,107 Mittal Rahul ,104,105 Mobarki M ,21, January,

166 Mohan G Mohan Kapil... 63,99,100,62,63,75,76 Mohanty S.... 9,12,13 Mohanty William K ,50,70,110 Mohapatra Alok Kumar... 20,50 MonaLisa Mondal Apurba Mondal S.K Mori Jim... 1,4 Morino M ,64 Morino Michio... 27,64 Mr. Sunjay Mukhopadhyay Basab Mualchin Lalliana Mukhtar G.A Murty C. V. R N Nagabhushanam P... 41,28 Namita Pegu Navalgund R R Nawani P.C Naik Sambit P Nayak Shailesh Nazari H Nekrasova Anastasia K.... 3,64 Negishi Hiroaki... 4 O Olimat Waleed Eid Oveisi1 B P P Anbazhagan P Sasidhar P. Mahesh P. Pradeep Pande Prabhas... 1,9 Pandey.O.P Pandey Ajeet P ,40 Panza G.F... 65,66 Parvez Imtiyaz... 66,64 Paskaleva I Patel Vandana... 6 Patel girish Patel H. S Patel V. M Patra.N. R Paul Ajay Peláez J.A Peresan A ,66 Pérez.Omar J Petersen Mark... 3 Pradhan Rashmi... 46,80,29 Prakasam K.S Prakash Rajesh Prasad B. Rajendra Prasad M.S.B.S Q Qorashi M R R. Meena Raghukant S T G Rai S.S Rajaram Mita Rajaraman R Ramola R.C Rani Kavita... 63,102 Rajawat A S Rao.N. Purnachandra... 13,23,24,25,72 Rao Ch. Nagabhushan Rao D. Gopala Rao D.T Rao N. Purnachandra... 13,23,24,25,72 Rastogi B. K.... 1,6,14,29,46,76,61,75,81,111,15,25 Rawat Vineeta Ray Indrajit Reddy C.D Reddy D.V ,41 Rehman Saifur Rodkin M.V Rodríguez Carlos Romanelli Fabio Romashkova Leontina L Roy K. S Roy P. N. S Roy Raghupati Rust Derek S S Rajesh Sahoo Santiswarup January, 2011

167 Saikia D Sairam B ,77,107 Santosh B ,104,105 Saraf Arun K Sarkar Shivalika Sarma Rajgopal Sato Tamao... 4 Satyanarayana H.V.S Segawa Shukyo Sen P Shah A. A Shah R.D... 5 Shah V R Shandilya Anurag Shaikh Md Babar Sharma Babita... 83,87 Sharma Kanika Shashidhar D Shen Wen-Bin Sheth Alpa Shokri M Shukla A.K ,74 Singh Anshuman ,104,105 Singh Ramesh P Singh A. P ,75,76 Singh Anshuman... 18,20 Singh B... 8 Singh Arun Singh R. K ,80 Singh Satish C Singh Savita Singh U.P ,104,105 Singh Yogendra Sinha B Sinha Sushmita Singhvi A ,120 Sitharam T.G ,67 Sivar K Solanki P.M... 5 Solomon Raju P Sreejith K. M ,93 Srijayanthi G ,24 Srinagesh D ,23,24 Srivastava H N... 43,74 Sukhtankar R. K Sumedha, Sunil P.S Suraweera S.A.D.L.K Suresh G Suresh N Surve,G Sushini K Suzat Yazdana T Talbi A... 20,21 Talwani Pradeep ,130 Teotia S.S Thiruppugazh V Tiwari Arjun Tripathi Jayant N U Umamaheswari A Ugalde A V Vaccari F ,70 Vaghmare Dr. Rajeev Vaideswaran Swapnamita C Verma Akhilesh K ,17 Verma U.S.P.101 Vikrama Bhuvan Vipin Dr. K.S ,72 W Wadhawan Monika Walia Vivek Wang Dijin Wen K. L Wenzel Friedemann Winston S. Joseph Y Yadav Renu Yang T. F Yadav Dilip Kr Yi Jun Z Zafarani H Zuccolo E Zala Kishansinh January,