Probabilistic Seismic Hazard - J-SHIS 地震ハザー … for this area is included in shallow...

Ground motion intensity for a given exceedance probability

Exceedance probability for a given ground motion Intensity

t yea

r exc

eeda

nce

prob

abili

ty

(loga

rithm

ic sc

ale)

確率地震予測評価之課題

Ken XS Hao (郝憲生) 　　独立行政法人　防災科学技術研究所 National Research Institute for Earth Science & Disaster Prevention

Probabilistic Seismic Hazard Assessment in general issues

TEM-‐NIED Workshop At NCU, June 4-‐6 2012

Seismic Hazard Assessment Issues in the island arc of Taiwan and Japan

Ø 1. Seismic ac�vity in Island arc of Taiwan and Japan

Ø 2. Probabilis�c Seismic Hazard Assessment Ø Modeling of Seismic Ac�vity

Ø  Classifica�on into 3 category

Ø  EQ without specified source faults

Ø Uncertainty

Ø  Reality on East Japan

Ø 3. Coopera�ve works on PSHA Ø  Historical records

Ø  Sharing EQ database

Ø  Person exchange

The big quakes might be considered “black swans”, for they are rare, had an extreme impact on society. But being rare is not the same as being an outlier that invalidates a par�cular probability model or overturns a methodology. Consequently, it is not obvious that our models and methods are in need of repair (Ellsworth, 2012).

convergent

ISLAND ARC OF TAIWAN AND JAPAN

divergent

Subduc�on

Ma Kuo-‐Fong, 2011, GEM

Four Plates of Eurasia, North American, Pacific and Philippines joined in Japan with 4,000 km of subduction zones

地震調査委員会（2004）

安芸灘（Akinada）ß-‐-‐-‐-‐à日向灘(Hyuganada)

Bathymetry and Tectonic Setting near Taiwan

Ma Kuo-‐Fong, 2011, GEM

2. Probabilis�c Seismic Hazard Assessment   Modeling of Seismic Ac�vity   Classifica�on into 3 category

  EQ without specified source faults   Uncertainty   Reality on East Japan

National seismic hazard maps for Japan Long term evaluation

Probability of occurrence, magnitude, location

Strong-motion evaluation

Strong-motion, underground structure

Probabilistic Seismic Hazard Maps

・・Strong-motion intensity with a given probability, or the probability with a given intensity.

・Considering all possible earthquakes.

Scenario Earthquake Shaking Maps

・・Strong-‐mo�on intensity around the fault for a specified earthquake.

System for the national seismic hazard mapping project

Surveys for active faults

Surveys for underground structure

Long-term evaluation

Study on methods to make probabilistic

seismic hazard maps

Study on methods　　 to make scenario earthquake maps

Evaluation of Strong-motion

National Seismic Hazard Maps for Japan

Advanced m

aps

Japan　　

Seismic H

azard Inform

ation Station (J-SHIS)

NIED ERC

National Research Institute for Earth Science and Disaster Prevention, Japan

独立行政法人防災科学技術研究所

November 2009

Technical Reports on National Seismic Hazard Maps for Japan

Technical Note of the National Research Institute for Earth Science and Disaster Prevention

No.336

Table of Contents 1. Introduc�on Outline 2. Seismic Source Fault Models for Characteris�c Earthquakes in Long-‐Term Evalua�on (pp 41)

2.1 Major Ac�ve Fault Zones 2.2 Subduc�on-‐Zone and Eastern Margin of the Japan Sea

3. Probabilis�c Seismic Hazard Maps (PSHM) (pp 357)

3.1 Evalua�on Procedure and Its Result Representa�on 3.2 Area Covered by the PSHM and Map Specifica�ons 3.3 Seismic Ac�vity Evalua�on Models 3.4 Earthquake Category 3.5 Ground Mo�on Evalua�on Models 3.6 Change Logs for the Used Parameters of Probabilis�c

Seismic Hazard Maps 3.7 Evalua�on Results

Technical reports on Na�onal Seismic Hazard Maps for Japan (2009) h�p://www.j-‐shis.bosai.go.jp/en/downloads

National Research Institute for Earth Science and Disaster Prevention, Japan

独立行政法人防災科学技術研究所

November 2009

Technical Reports on National Seismic Hazard Maps for Japan

Technical Note of the National Research Institute for Earth Science and Disaster Prevention

No.336

Table of Contents (Con�nued) 4. Seismic Hazard Maps for Specified Seismic Source Faults

(pp 36)

4.1 Procedure and Results of Evalua�on & Presenta�on Method

4.2 Areas Covered by the SHM and Its Specifica�ons 4.3 Determina�on of the Inner Source Parameters and

Others of Characteris�c Earthquakes Occurring in Major Ac�ve Fault Zones

4.4 Subsurface Structure Models 4.5 Method of Strong Mo�on Simula�on rela�on 4.6 Evalua�on Results

5. Japan Seismic Hazard Informa�on Sta�on (J-‐SHIS) (pp 19) 5.1 Outline 5.2 Objec�ves 5.3 Technical Background 5.4 J-‐SHIS System 5.5 Toward Sending Informa�on on Earthquake Risk

6. Toward the Future (pp 3) 7. Closing Remarks Acknowledgments Appendix Strong Ground Mo�on Predic�on Method ("Recipe") for Earthquakes with Specified Source Faults (pp 50)

Technical reports on Na�onal Seismic Hazard Maps for Japan (2009)

Modeling of Seismic Activity

Earthquakes of which the seismic source fault is specified (earthquakes occurring in major active fault zones, subduction-zone

earthquakes, and earthquakes at any other active faults) Earthquakes without specified source faults

Target site

Evaluation of the probabilities of magnitude, distance and earthquake occurrence (frequency)

Probability function of the magnitude Pk(mi)

Probability function of the distance where the

magnitude is mi Pk(rj|mi)

Magnitude Magnitude Distance Distance

Prob

abili

ty

Prob

abili

ty

Prob

abili

ty

Prob

abili

ty

Earthquake occurrence probability P(Ek;t) or occurrence frequency v(Ek)

Earthquake occurrence frequency v(Ek)

Target site

Target site

Probability function of the magnitude Pk(mi)

Probability function of the distance where the

magnitude is mi Pk(rj|mi)

For known faults: Unknown faults:

Modeling of seismic activity

Magnitude i distance j

Stationary Poisson process

Poisson G-R relation

BPT distribution based on a renewal process

Probability that the ground motion intensity exceeds a certain level where earthquake k has occurred

Probability that the ground motion intensity exceeds level y where the

magnitude is mi and the distance is rj

Probability distribution of ground motion intensity

Hazard curve for each earthquake

Distance

Gro

und

mot

ion

inte

nsity

Earthquake k

Ground motion intensity

Probability that the ground motion intensity exceeds a certain level within t years as a result of the target

earthquake (earthquake cluster) k

or

t-yea

r exc

eeda

nce

prob

abili

ty

Hazard curve integrating the results for all earthquakes

t-yea

r exc

eeda

nce

prob

abili

ty

Ground motion intensity

Prob. for each earthquake P(Y > y)= P(Ek) P(Y > y|Ek)

Prob. for all Eqs Ek P(Y > y)=1-Π[1- P(Yi > y)]

Exceedance Prob. of an intensity level P(Y > y|Ek)

Magnitude i distance j earthquake k

Ground motion intensity for a given exceedance probability

Exceedance probability for a given ground motion Intensity


12/06/13

Classifica�on into Earthquake category EQ category I EQ category II EQ category III

Characteris�c Subduc�on-‐zone Earthquakes

Fused Subduc�on-‐zone Earthquakes Crustal Earthquakes

3.3.3 Earthquakes occurring on Ac�ve faults

Ø  Determina�on of the earthquake occurrence probability

Ø  R (year) : Mean recurrence interval

Ø  R = D / S * 1000 Ø  Where, D (m) = displacement per event; Ø  S (mm/year)= average slip rate

Ø  log R = log L / S + 1.9 Ø  Where, fault length L

Ø  log L = 0.6 M -‐ 2.9; (Matsuda, 1975)

Ø  log D = 0.6 M -‐ 4.0 ;

Ø  For the unknown of average slip rate, Ø  ac�vity levels are grouped as Ø  Class A: 1 mm/y Ø  Class B: 0.25 mm/y Ø  Class C: 0.047 mm/y

EQ category III Technical reports on Na�onal Seismic Hazard Maps for Japan (2009)

3.3.4 Earthquakes without specified source faults

3.4.3-8 Idea of distinguishing between interplate earthquakes and intraplate earthquakes (SLTE/SESGM, ERC, 200

all earthquakes are regarded earthquakes

Area where distinction is made between interplate earthquakes and intraplate earthquakes based on a ratio

urface of the Earthquakes deeper than this line

are regarded as intraplate earthquakes

Ø  The Earthquake Occurrence Ra�o Ø  R = between Interplate and intraplate

EQ category II Technical reports on Na�onal Seismic Hazard Maps for Japan (2009)

Figure 3.3.4.9-1 Target earthquakes of earthquakes without specified source faults in the vicinity of Nansei

(a) Shallow earthquakes in the vicinity of Nansei-shoto islands

(b) Earthquakes in the vicinity of Yonaguni-jima

Shallow earthquakes in the vicinity of

Nansei-shoto islands

Upper surface of the Philippine Sea plate

Evaluated as earthquakes at the Philippine Sea plate (Relatively deep earthquakes from Kyushu to the vicinity of Nansei-shoto islands) Relatively deep

earthquakes

Data for this area is included in shallow earthquakes.

Earthquakes in the vicinity of

Yonaguni-jima

Upper surface of the Philippine Sea plate Since relatively deep earthquakes have not

been modeled in the vicinity of Yonaguni-jima, earthquakes shallower than 100 km are treated collectively.

Figure 3.3.4.9-5 Occurrence frequency of earthquakes without specified source faults in the vicinity of Nansei-shoto islands (per 0.1-degree square, M5.0 or more)

X 10-4 [times/year]

Occurrence frequency of Earthquakes (M>5) without specified source faults


2009 version (data: - Dec. 2007) Rate of change = (2009-2008)/2008 2008 version (data: - Dec. 2006)

Figure 3.3.4.10-2 Occurrence frequency of earthquakes without specified source faults in the Philippine Sea plate (Total for interplate and intraplate earthquakes)

X 10-4 [times/year] X 10-4 [times/year]


Uncertainty: U = Ur_+Uk

１．Ur: Aleatory (Random) Uncertainty

  Time of EQ occurrence

  Location of EQ occurrence

  Source properties (e.g. M) of EQ occurrence

  Ground motion at a site

  Given the median value of motion

  Inner Source parameters，fault rupture process(e.g.,

direction of rupture　震源の微視的)

  Geometry of seismotectonic and seismo-genic zones

  Distributions describing source parameters

(e.g., rate, b value, maximum M)

  Median value of ground motion given the source properties

  Limits on ground shaking

２．Uk: Epistemic (Knowledge) Uncertainty 情報不足->不確定性

Common logarithm standard deviation σ

Seismic intensity in 3% exceedance probability within 30 years

σ = 0.23 σ = 0.15

Random phenomenon (Aleatory uncertainty ) was considered in hazard curve calcula�on

Reduce uncertainty by using variance σ depending on Velocity amplitudes

Com

mon

loga

rith

mic

sta

ndar

d de

viat

ion Conventional value (0.23)

Value to be used for the National Seismic

Hazard Maps for Japan

Estimated value of the peak velocity (cm/s) on the engineering bedrock (Vs = 600m/s)

3.3.2 Subduc�on-‐zone Earthquakes

3.2-3 Areas covered in evaluation of the Miyagi-ken-Oki Earthquake and earthquakes in the Sanriku-Oki to Boso-Oki

regions.

A: Miyagi-ken-Oki B: Northern Sanriku-Oki C: Close to the offshore

trenches in the Northern Sanriku-Oki to Boso-Oki regions

D: Central Sanriku-Oki E: Close to the offshore

trenches in Southern Sanriku-Oki

F: Fukushima-ken-Oki G: Ibaraki-ken-Oki

B

Japan Trench

A

C D

E

F

G

We did pointed out that a M7.4 to 8.0 earthquake in Miyagi-ken-Oki, area A, with probability of 99%, would be occur within 30 years.

However, the ruptures trigged areas A, E, D, F, G and C simultaneously, over a region of 500km x 200km, which was far beyond our considerations. The maximum M was underestimated.


Major earthquakes on ac�ve faults and subduc�on zone with low-‐probability. Regarding the PSHA for low probability, at presen it is insufficient to evaluate the uncertainty for low probability of M8-‐class earthquakes and it is necessary to improve techniques for them.

1,000 years 10,000 years 100,000 years

How to give the warning or message to public, for unexpec�ng event, or low probability but destruc�ve events,

Strong-motion maps considering low-probability earthquakes

convergent

ISLAND ARC OF TAIWAN AND JAPAN

Prepara�on for the next M9

3. Coopera�ve works on PSHA

  Historical records   Sharing EQ database

  Person exchange

What lessons we have learnt from the Tohuku earthquake? “The borderless world of Science” à enabling knowledge and data exchange each others.

Subduc�on zones à Crossing border connect the world

Earthquakes without specified source faults in the vicinity of Ryukyu islands

Arrows -‐> Earthquake occurrence regions

地震調査委員会（2004） W.-‐J. Huang, et al, 2010

Subduction zones for Island arc 地震調査委員会（2004）

Interna�onal Coopera�on à

Trilateral coopera�ve program enabling knowledge data exchange

Approved and supported by each individual coun�es

New Release www.j-shis.bosai.go.jp/intl/cjk

à SHA for Next Genera�on

12/06/13

à Welcome to Coopera�on with TEM

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