Earthquake Seismology and Earthquake Hazard

Transcription

1 Earthquake Seismology and Earthquake Hazard Peter Sammonds

2 Earthquake Seismology and Earthquake Hazard Course details GH07 MSc Geophysical Hazards GEOLGG09 MSc Geoscience / Earthquake Engineering GEOL4002 MSci Geophysics etc. M (masters) level course ECTS (PG) Half course unit (UG)

3 Earthquake Seismology and Earthquake Hazard Course organiser Peter Sammonds Professor of Geophysics Department of Earth Sciences Office: Pearson Building, 2 nd p.sammonds@ucl.ac.uk Course website: Other contributors Alan Douglas Blacknest Observatory 1 day Tim Wright COMET, Leeds University 1 day Tiziana Rossetto Civil Engineering, UCL 1 lecture Clare Matthews Earth Sciences, UCL PG teacher Joanna Faure Walker Earth Sciences, UCL PG teacher

4 Earthquake Seismology and Earthquake Hazard Workload a) 20 Lectures 20 hrs b) 6 Self-guided tutorials 18 hrs c) 3 Analytical/computing practicals 16 hrs d) Study visit to seismological observatory 6 hrs e) Earthquake hazard eercise 6 hrs e) Private reading hrs f) Practical write ups hrs g) Revision 30 hrs Total: hrs Assessment Written eamination: 80% 2 hrs 30 mins Coursework: 20% 2/3 Practical write-ups Both eamination and coursework must be passed

5 Earthquake Seismology and Earthquake Hazard Times & venues Monday 1.00pm to 6.00pm Wk1: Starting Monday 1 st October Lectures & Practicals: 188 Tottenham Court Road, Room SB5 Computer practicals: Computer Terminal Room, 2 nd flr South Wing (PIN: 25334) & Lewis Workroom, Basement Lewis Earthquake Hazard Eercise

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7 Earthquake Seismology and Earthquake Hazard Blacknest trip Compulsory eercises at Blacknest Wednesday / Thursday 7 th /8 th November Lecture Half day visit depart am Paddington Professor Alan Douglas Blacknest Seismological Observatory MoD, AWE Aldermaston

8 Earthquake Seismology and Earthquake Hazard Course outline Observational Seismology Earthquake Waves & Seismograms IASPEI Seismology Handbook Visit to Blacknest Observatory Earthquake Source Mechanics Seismic Moment & Seismotectonics Earthquake magnitude & intensity Seismometer Theoretical Seismology Signal Processing Tutorial

9 Tectonics Strain-Stress Tensors State of Stress in the Crust Earth Materials Satellite Remote Sensing Earthquake cycle deformation Interpreting interferograms Earthquake Hazard Eercise Earthquake engineering Earthquake Recurrence Earthquake Statistics Realistic Disaster Scenarios

10 Earthquake Seismology and Earthquake Hazard 1. Propagation of seismic waves Observational seismology How to interpret a seismogram:- analyse both old ink trace and modern digital records analysing earth structure

11 Earthquake Seismology and Earthquake Hazard 2. Earthquake source mechanics Seismotectonics using Matlab Determining the earthquake focal mechanism:- Seismotectonics:- earthquake hazard assessment

12 Earthquake Seismology and Earthquake Hazard 3. Propagation of seismic waves Theoretical seismology Understand elastodynamic equation:- solutions to it tell us about the earthquake source, seismotectonics, earth structure, ground motion ( ) + + = + + = + = i j j j j i k i k i j j i k k ij j ij kk ij j j ij u u u u u u μ λ μ λδ με ε λδ σ

13 Earthquake Seismology & Earthquake Hazard 4. Earthquake faulting Analysis of strain & stress Observed interferogram calculated from ERS-1 SAR images taken before and after the Izmit Earthquake

14 Earthquake Seismology and Earthquake Hazard 5. Earthquake source mechanics Earthquake models and scaling Friction and fluid flow models of earthquakes:- Slip weakening model Rate and state models Coulomb stress model Fractal scaling

15 Earthquake Seismology and Earthquake Hazard 5. Earthquake design Ground motion & damage Social & economic impact Ground motion from wave equation Tsunami Shake maps Soils and structures

16 Earthquake Seismology and Earthquake Hazard 6. Forecasting earthquakes Earthquake statistics Poisson statistics Non-Poissonian statistics Etremal statistics Hazard maps: practical hazard assessment Approaches to forecasting and warning

17 Great Kanto Earthquake 1923 Great Kanto earthquake (Mw = 7.9; M s = 8.2) Occurred along the Sagami Trough in the Sagami Bay on 1 September 1923 One of the most disastrous earthquakes in Japanese history Refugees Imperial Palace Saiten Tamura Earthquake claimed 99,331 dead, 43,746 missing, and left 3.4 million homeless Major social consequences - systematic massacre of 6,000 Koreans & political assassinations

18 Great Kanto Earthquake 1923 JMA Intensities

19 Great Kanto Earthquake 1923 Ratio of total collapse of wooden houses

20 Great Kanto Earthquake 1923 Tsunami height reached 12 m at Atami in Shizuoka Prefecture and 9.3 m at Aihama on the Boso Peninsula The tsunami struck Atami, located close to the focal region, about 5 minutes after the earthquake occurred Hence the tsunami was not triggered directly by the earthquake itself, but a subsequent submarine landslide There was no large tsunami wave inside Tokyo Bay Tsunami damage Yuigahama Beach

21 Great Kanto Earthquake 1923 Lloyd s realistic disaster scenarios USA Windstorm, Marine Collision in Prince William Sound, North Sea- Loss of Major Comple, Aviation Collision, Satellite Risks, Political Risks, Liability Risks Compulsory Scenarios Second Event, Florida Windstorm, California Earthquake, New Madrid Earthquake, European Windstorm, Japanese Earthquake, Terrorism Objective is for syndicates to estimate losses in a variety of hypothetical disaster scenarios Wanted me to assess how realistic this scenarios was and the impacts, including a tsunami assessment

22 Great Kanto Earthquake 1923 JMA Intensities: Maimum is 7 Lloyds RDS: is it realistic?

23 Reading list Recommended Tets Shearer P M (1999) Introduction to Seismology, C.U.P. Bolt B A (2003) Earthquake 5 th edition, W H Freeman & Co., New York Woo G (1999) The Mathematics of Natural Catastrophes, Imperial College Press An advanced tet from an unusual viewpoint, directed towards the insurance industry. Fowler C M R (2005) The Solid Earth 2 nd edition, Cambridge University Press A general introductory geophysics tet Vita-Finzi C (2002) Monitoring the Earth, Terra Readable account of active tectonics