after the 2011 Tohoku earthquake Hiroyuki Fujiwara National Research Institute for Earth Science and Disaster Prevention

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1 Seismic hazard assessment for Japan after the 2011 Tohoku earthquake Hiroyuki Fujiwara National Research Institute for Earth Science and Disaster Prevention

2 National seismic hazard maps for Japan Long term evaluation Strong-motion evaluation Probability of occurrence, magnitude, location Strong-motion, ti underground d structure t Probabilistic Seismic Hazard Maps Scenario Earthquake Shaking Maps Showing the strong-motion intensity with a given probability, or the probability with a given intensity. Considering all possible earthquakes. Showing the strong-motion intensity around the fault for a specified earthquake.

0 1000 2000 3000 4000 5000 6000 7000 深度 (m) 下五十嵐新竹野町升潟石油公団 (1968a) 石油公団 (1994) 大淵石油公団 (1968b) P 波速度 (km/s) 1 2 3 4 5 6 1.6 魚沼魚沼 387 611 679 826 灰爪 910 1.9 1000 魚沼魚沼魚沼灰爪魚沼 + + 西山灰爪灰爪 1518 1700 2.

8 寺泊寺泊 4568 七谷 4659 寺泊 4920 4979 4903 グ 5015 グリーンリグタフリ 6310 ンタフグリーンタフ 38.5 38.33 38.17 38 37.83 37.67 37.5 37.33 37.17 37 36.

2 2070 2970 5000 上部寺泊下部寺泊グリンタフ 5.4 3.6 4.1 吉田石油公団 (1970a) 2064 3600 4430 5006 P 波速度 (km/s) P 波速度 (km/s) 1 2 3 4 5 6 1 2 3 4 5 6 椎谷 2.2 242 魚沼 2.1 上部寺泊 3.8 魚沼 837 + 956 3.7 灰爪灰爪 2.

2 下部寺泊 3127 七谷 3853 6100 グリンタフ東山石油公団 (1999) 8000 7000 6500 6000 5500 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 400 300 200 100 50 0 4.4 5.

4 深度 (m) 下五十嵐新竹野町升潟石油公団 (1968a) 石油公団 (1994) 大淵石油公団 (1968b) P 波速度 (km/s) 魚沼魚沼灰爪魚沼魚沼魚沼灰爪魚沼 + + 西山灰爪灰爪灰爪西山椎谷 2932 灰爪 3200 西山西山西山 3.5 西山 3743 上部寺泊椎谷下部椎谷上部寺泊 3.8 寺泊寺泊 4568 七谷 4659 寺泊グ 5015 グリーンリグタフリ 6310 ンタフグリーンタフンタフ新潟平野新津石油公団 (2003) 石油公団 (2003) P 波速度 (km/s) P 波速度 (km/s) 魚沼灰爪 500 西山椎谷上部寺泊下部寺泊グリンタフ吉田石油公団 (1970a) P 波速度 (km/s) P 波速度 (km/s) 椎谷魚沼 2.1 上部寺泊 3.8 魚沼灰爪灰爪西山椎谷寺泊 2264 西山椎谷 3490 上部寺泊 4032 下部寺泊 5809 七谷 5982 グリーンタフ 6300 三島石油公団 (1993) 下部寺泊 3127 七谷グリンタフ東山石油公団 (1999) Development of Integrated Geophysical and Geological Information Database 石油公団 (1994) 月潟石油公団 (1991b) Information on underground structure Management system on sharing for Integrated Database NIED AIST PWRI Database of geological information Database of underground structure Database of soil dynamics Municipalitie s DB Coordination and integration by the network ERI of Tokyo University Utilization of the database Tokyo Institute of Technology JGS s database Reduction of natural disaster Construction of safe, secure and sustainable society

5 Japan Seismic Hazard Information Station hi i j In order to promote the use of the national seismic hazard maps, an engineering application committee (Chairman: Prof. H. Kameda) was established by NIED. Under the committee guidance, we developed an open web system to provide information interactively, and named this system as Japan Seismic Hazard Information Station, J-SHIS. Our products are aimed to meet multi-purpose needs in engineering fields by providing information of the probabilistic seismic hazard analysis.

The ground motions were recorded at more

6 The 2011 Tohoku earthquake This M9.0 megathrust earthquake initiated approximately 100 km offshore of Miyagi prefecture and the rupture extended 500 km along the subducting Pacific plate. The Tohoku earthquake was the first M9-class earthquake that is recorded by dense seismograph network. The ground motions were recorded at more than 1200 K-NET and KiK-net. The peak ground accelerations (PGA) exceeded 1G at 20 sites and the largest PGA, 2933 gal was observed at the K-NET Tsukidate station (MYG004).

7 Paste-up of the observed waveforms Acceleration EW component Displacement ( Hz) EW component Normalized acceleration and displacement ( Hz) paste-up of the waveforms observed by K-NET and KiK-net ordered by latitude which reveal a very complex source process; An initial strong phase originating near the hypocenter is clearly observed. A subsequent seismic phase uniformly delayed by approximately 40s suggests a second event at nearly the same location. A later seismic phase is strongly observed to the south s after the initial phase. This phase suggests that a third strong event took place off-shore of Fukushima-Ibaraki.

8 Observation facilities damaged by the tsunami K-NET (IWT004) K-NET (IWT006) K-NET(3 observation sites) Taro(IWT004) Yamada(IWT006) Kitakami(MYG008) K-NET (MYG008) KiK-net (MYGH12) KiK-net(2 observation sites) Shizukawa(MYGH12) Senadai(MYGH01) KiK-net (MYGH01)

9 Height of Tsunami and Inundation Area Rikuzen-takada st. Ofunato city Rikuzen-takada city Kesen-numa city Taihaku ward Wakabayashi ward Natori city Shibata town Watari town Iwanuma city

10 Overview of Damages Prefecture House Damage Totally collapsed Partially destroyed d Missing and Dead Hokkaido Aomori Iwate 20,184 4,551 6,050 Miyagi 82, ,587 11,350 Yamagata Fukushima 19,157 58,603 2,008 Ibaraki 3,012 22, Tochigi i 265 2,048 4 Gunma Saitama Chiba 797 9, Tokyo Kanagawa Total 126, ,600 19,479

11 House Damages by the Great East Japan Earthquake Disaster

12 Category Building Residence, Shop, Office, Factory, Machinery etc. Lifeline Water supply, Gas, Electricity, Communication Infrastructure Economic Impact Estimated Loss (JPY trillion) The Great East Japan The Great Hanshin-Awaji Earthquake (2011) Earthquake (1995) by Cabinet Office, Gov. Of Japan River, Road, Port, Sewage, Airport Agriculture, Forestry and Fisheries 1.9 by National Land Agency Other Other 1.1 Total Total loss of the listed companies amounted to JPY 3.1 trillion One third of companies, which are listed in the first section of the Tokyo Stock Exchange and fiscal year ending March, posted a loss. About 20 companies posted a loss of over JPY 10 billion

13 Japan Worldwide Claims Paid for Major Disasters USD 1 = JPY 80 Category Event Name (Year) Total Loss Claims Paid (USD billion) (USD billion) personal insurance East Japan (2011) personal mutual aid Earthquake corporate 7.5 personal Hanshin-Awaji (1995) insurance personal mutual aid Typhoon MIREILLE (1991 No.19) Earthquake Northridge (1994) Katrina (2005) Hurricane Andrew (1992) Terrorism 9.11 WTC (2001) Cabinet Office, Government Of Japan, 2 National Land Agency, 3 National Research Institute for Earth Science and Disaster Prevention, 4 The General Insurance Association of Japan, 5 JA mutual Aid, 6 SwissRe, Sigma2011, No1

14 Lessons from the Tohoku Earthquake Complex wide-area disaster The limits of crisis management for complex wide-area disaster were exposed. Lack of Bird's-eye view for response to disaster Lack of comprehensive measures Elemental technologies were effective. (Earthquake-proof technology) Limits of elemental technologies that are optimized for the event in the expected. Lack of measures for unexpected events Needs for an integrated system for disaster mitigation Improvement of national power for disaster management and mitigation by reform of the social system Operational integration of disaster management and mitigation system as a service

Comparison between the hazard maps and observed strong motions Comparison

earthquake and seismic intensity distribution for 2% probability of exceedance

7 6+ 6-5+ 5-4 3 or less As you can see from this comparison, predicted ground

underestimated in Fukushima Prefecture and the northern part of Ibaraki

15 Comparison between the hazard maps and observed strong motions Comparison between the observed seismic intensities ( :K-NET, :KiK-net)of the Tohoku earthquake and seismic intensity distribution for 2% probability of exceedance in 50 years, which is one of the probabilistic seismic hazard map or less As you can see from this comparison, predicted ground motion level in the probabilistic seismic hazard map was clearly underestimated in Fukushima Prefecture and the northern part of Ibaraki Prefecture for the Tohoku earthquake. seismic intensity Seismic Intensity with 2% probability of exceedance in 50 year.

16 Flowchart of PSHA Modeling of seismic activity Evaluation of an EQ occurrence probability P(Ei) Probabilistic evaluation of an intensity level P(Yi > y Ei) Evaluation of probabilistic seismic hazard for each earthquake P(Yi > y)= P(Ei) P(Yi > y Ei) Evaluation of probabilistic seismic hazard for all earthquakes P(Y > y)=1-π[1- P(Yi > y)]

17 Evaluation of occurrence probability of earthquakes by ERCJ

19 Modeling of seismic activity in the Pacific plate before the 311 Tohoku earthquake M=8.0 6% Mu=7.0 M=7.5 >99%? M=7.7 81% Mu=7.0 Mu=7.2 Mu=7.5 M=7.4 7% M=7.0 99% M=8.2 5% Mt=8.2 20%? Mu=7.0 Mu=7.1 Mu=7.3 Mu=7.5 M for characteristic earthquakes Max M for background earthquakes

20 Seismic activity model for hazard assessment Earthquakes with specified dfault Earthquakes in major or other fault zones Earthquakes in subduction zones (Interplate or intraplate) Background earthquakes Inland earthquakes Earthquakes in subduction zones (Interplate or intraplate) In order to construct a probabilistic seismic activity model that encompasses the seismic activity of all possible earthquakes, it is necessary for the complement the long-term evaluation to use a different methodology from the traditional long-term evaluation.

21 Classification of uncertainty factors Aleatory Uncertainty Intrinsic uncertainty. It is represented by a random variable in the prediction model. Uncertainty caused by a limitation of model to explain phenomena. Uncertainty used to calculate a hazard curve. Epistemic Uncertainty Uncertainty due to a lack of knowledge and data. Uncertainty due to differences in judgment for modeling It is evaluated by using a logic tree. Represented by more than one hazard curve.

22 Problems that must be overcome for improvement of seismic i hazard assessment 1) Modeling of seismic activity with no oversight to low-probability earthquakes. 2) Preparation of strong ground motion maps considering low-probability earthquakes. 3) Development of methodology for selecting appropriate scenario earthquakes from probabilistic seismicity model. 4) Development of methodology for prediction i of strong ground motions for mega-thrust earthquakes.

23 Seismic activities in the Pacific plate No.1 No.2 (G-R law) It is necessary to promote proper modeling of background earthquakes that encompasses all earthquakes without longterm evaluation. For example it may be possible to evaluate the magnitude of For example, it may be possible to evaluate the magnitude of earthquakes from the area of the plate boundary that can be considered to cause earthquakes, and to assess the frequency of occurrence of earthquakes by using the Gutenberg-Richter formula that shows the relationship between the number of earthquakes and their magnitude.

24 Tentative modeling of seismic activity in the Pacific plate after the 311 Tohoku earthquake M=8.0 7% Mu=7.0 M=7.4 (55%)? Mu=8.0 or 8.2 M=7.9 0% M=7.4 14% M=7.0 95% M=8.2 5% Mt= % Mu=8.0 or 8.4 Mu=8.0 or 8.4 Mu=8.0 or 8.2 Mu=8.0 Mu=8.0 or 8.3? Mu=8.0 or 8.3 Intraplate Mu=7.5 or 8.2 M for characteristic earthquakes Max M for background earthquakes (Model 1 or Model 2)

25 PSHM taking into account the Tohoku earthquake (M9) Setting conditions for the Tohoku EQ Source area: Aftershock area The origin of the time:2011/1/1 Average interval: 600 years Latest activity period: 15th century Occurrence probability in 30 years: 15.4% G d ti ti Ground-motion equation: Si and Midorikawa(1999) (Saturated with Mw8.3)

26 PSHMs considering the Tohoku type earthquake (a) PSHM2011 (b) PSHM2011+TohokuM9

27 Strong-motion maps considering low-probability earthquakes 1,000 years 10,000 years 100,000 years Based on the averaged long-term seismic hazard assessment, evaluating strong-motion level for about 10, , years return period, we prepare the maps that show the distribution of strong-motion level, which represent effect of almost all of major earthquakes on active faults and subduction zone earthquakes with low-probability. Regarding the seismic hazard assessment for low probability, at present, it is insufficient to evaluate the uncertainty for low probability M8 class earthquakes and it is necessary to improve techniques for them.

28 The East Japan Earthquake and Other Major Earthquakes Massive Earthquake Model along Nankai Trough by the Central Disaster Prevention Council (2011) The Great East Japan Earthquake North Tokyo Bay The Great Kanto 1923 Genroku 1703 JMA Seismic Intensity for the 3 Coupled Earthquakes along Nankai-trough were evaluated by the Central Disaster Prevention Council (2003)

29 Historical and Assumed Earthquakes Event Name Estimated Population in the Area (million) 5+ SIJMA 6- SIJMA Property Loss (JPY trillion) Estimating Organization The Great Hanshin-Awaji Earthquake (1995) The Great East Japan Earthquake (2011) National Land Agency Cabinet Office, Government Of Japan 3 coupled Earthquakes along Central Disaster ~60 Prevention Council (2003) Nankai-trough (Tokai, To-Nankai, Nankai EQ) Tokyo Metropolitan Earthquake (North Tokyo Bay Earthquake) Central Disaster Prevention Council (2005)

30 Prepare for disaster risk by the intelligence Natural disaster Expertise Disaster prevention Resilient Society Experimental knowledge Knowledge on the region Knowledge on themselves I di id l i i d i l k l d h i Individuals can acquire expertise and experimental knowledge that exist in distributed and utilize them and sophisticate their own intelligence for disaster prevention.

31 災害危険度メータ _ 自宅の登録家族の登録自宅の耐震評価備蓄登録ファイル編集表示ツールヘルプ緊急地震速報なし台風や豪雨予想危険度 3 大丈夫? なし災害危険度メータ _ 自宅の登録家族の登録自宅の耐震評価備蓄登録ファイル編集表示ツールヘルプ緊急地震速報なし台風や豪雨予想危険度 3 大丈夫? なし災害危険度メータ _ 自宅の登録家族の登録自宅の耐震評価備蓄登録ファイル編集表示ツールヘルプ緊急地震速報なし台風や豪雨予想危険度 3 大丈夫? なし Disaster-Risk Information Platform (BOSAI-DRIP) Geospatial Information Interoperability of information Damage Assessment Hazard Map History and Record of Universities, Institutes Governments Disaster Companies, NPOs Interoperable Institutions and Services Information Environment AIU(Japanese ABC) for BOSAI DRIP A I U Disaster-Risk Management System for Local Community Clearinghouse for DRI DRMS for I DRMS for LC DRI for Earthquakes DRI for Volcanic Eruptions DRI for Floods DRI for Landslides DRI for Heavy Snow and Ice Disaster-Risk Evaluation System DRMS for I Disaster-Risk Management System for Individual DRMS for LC Utiliz zation of informatio on Ad dvanceme ent of info ormation

32 Thank you for attention.

National Seismic Hazard Maps for Japan and an integrated system for sharing information, J-SHIS

National Seismic Hazard Maps for Japan and an integrated system for sharing information, J-SHIS H. Fujiwara, N.Morikawa, K. XS. Hao National Research Institute for Earth Science and Disaster Resilience