Seismic Hazard Assessment in Japan - J-SHIS … Hazard Assessment in Japan Hiroyuki Fujiwara National Research Institute for Earth Science and Disaster Prevention National seismic

Seismic Hazard Assessment in Japan

Hiroyuki Fujiwara

National Research Institute for Earth Science and Disaster Prevention

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

・Showing the strong-motion

intensity with a given

probability, or the probability

with a given intensity.

・Considering all possible

earthquakes.

Scenario Earthquake Shaking Maps

・Showing the strong-motion

intensity around the fault

for a specified earthquake.

Background of the Project

The Great Hanshin-Awaji Earthquake Disaster on January 17, 1995 killed 6,434 people and destroyed over 100,000 buildings, and brought to light a number of problems in our national earthquake disaster prevention measures.

Following on the lessons learned from this disaster, the Special Measure Law on Earthquake Disaster Prevention was enacted in July 1995 to promote a comprehensive national policy on earthquake disaster prevention.

Headquarters for Earthquake Research Promotion was established in accordance with the Special Measure Law on Earthquake Disaster Prevention (1995).


Promotion of Earthquake Research -（April 23, 1999）

－Comprehensive and Fundamental Measures for Promotion of

Observation, Measurement and Research on Earthquakes

(The 1st stage : 1999-2008)

Major subjects of Earthquake researches immediately

１．Preparation of seismic hazard maps based on surveys of active

faults, long-term evaluations of the probability of earthquake

occurrence, and evaluations of strong ground motion

２．Promotion of real-time transmission of earthquake information

３．Improvement of observation system for earthquake disaster

prevention

４．Promotion of observation and research for earthquake

prediction


The next Promotion of Earthquake Research -（April 21, 2009）

－Comprehensive and Fundamental Measures for Promotion of

Observation, Measurement and Research on Earthquakes

(The 2nd stage : 2009-2018)

The objectives of the earthquake research which should be promoted in the

coming 10 years are as follows.

(1) Improving the accuracy of the prediction of earthquake occurrence, strong

ground motion and tsunami based on the observation and research for the

subduction-zone earthquake

(2) Systematic accumulation and maintenance of the information for the

research related to active faults and advanced evaluation

(3) Strengthening of mediation function to promote the study on engineering

and social science for disaster prevention and disaster reduction

Probabilistic Seismic Hazard Map

Predicting possibility that a certain area is attacked

by strong ground motion in a given years.

・Showing the strong-motion intensity with

a given probability, or the probability with

a given intensity.

・Considering all possible earthquakes.

・Showing comprehensive ground motions

caused by independent earthquakes

Example of probabilistic map

PSHM Feature

Evaluation of occurrence probability of earthquakes

by ERCJ

Flowchart of PSHA

Modeling of seismic activity

Evaluation of an EQ occurrence probability P(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)]

Probabilistic evaluation of an intensity level P(Yi > y|Ei)


Probability in 30 years. (≧JMA Seismic Intensity 6-）

Seismic Intensity with 3% probability of

exceedance in 30 year.


≧JMA SI 6- ≧JMA SI 6+

≧JMA SI 5- ≧JMA SI 5+

These maps show the

probability in 30 years

with the JMA seismic

intensity more than or

equal 5-, 5+, 6-, 6+,

respectively.

Classification into Earthquake category

Earthquake

category 1

Earthquake

category 2

Earthquake

category 3

Characteristic Subduction-zone Earthquakes

Fused Subduction-zone Earthquakes

Crustal Earthquakes

1/4 2/4 3/4 1/4 2/4 3/4 1/4 2/4 3/4

Hazard Map for each earthquake category

Probability in 30 years. (≧JMA Seismic Intensity 6-）

interquartle

The 2011 Tohoku-oki earthquake

Comparison between the hazard maps and observed strong motions

Seismic Intensity with 2% probability

of exceedance in 50 year.

Seismic Intensity with 5% probability

of exceedance in 50 year.

Modeling of seismic activity in the Pacific plate

M for characteristic earthquakes Max M for background earthquakes

M=8.0

M=7.7

M=8.2 Mt=8.2

M=7.5

M=7.4

M=7.0

?

?

Mu=7.0

Mu=7.5

Mu=7.0

Mu=7.2

Mu=7.5

Mu=7.1

Mu=7.3

Mu=7.0

Issues to be solved for improvement of

seismic hazard assessment for Japan

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 of

strong ground motions for mega-thrust earthquakes.

Scenario Earthquake Shaking Maps

The shaking maps are evaluated for 490 scenario earthquakes

of almost all of major faults in Japan.

Selection of a specified scenario is essential to make a shaking map. The basic policy of the selection of a

scenario earthquake is that we choose the most probable case.

For treatment of uncertainties, we assume several cases of source model and compare the results of them to

show deviation of strong-motion evaluation due to uncertainties.

Theoretical approach for evaluation

of strong-motion

Amplification due to

thick sediment

Amplification due to soft soil near surface

Wave propagation in a

heterogeneous medium

Complicated

source process

Low frequency range

High frequency range

Hybrid method for evaluation of strong-motion

deterministic Stochastic

Finite Difference Method

Stochastic Green’s function method

Superposition

Low

frequency

range

High

frequency

range

Matching filter

The technical details on the hybrid method are summarized as the

‘Recipe for strong-motion evaluation’, which are published by the

earthquake research committee of Japan.

Characterized Source Model

Complicated source model

The complicated source model is simplified by the

characteristic source model for strong-motion prediction.

Characterized source models are composed of asperities and a

background slip area surrounding the asperities. Asperities are

the main rupture areas in the fault zone.

Source parameters required to evaluate strong-motions by

using the characterized source model are classified into three

parts.

The first part is the set of outer parameters that show the

magnitude and the fault shape of the earthquake.

The second part is the set of the parameters that describe the

degree of fault heterogeneity.

The third part is the set of the parameters to define the

characteristics of the rupture propagation.

Modeling of underground structure S

edim

ent

Source

Seismic bedrock

（Vs=3km/s）

Engineering bedrock

（Vs=0.4～0.7km/s）

Deep

und

ergro

und

structu

re S

urface

soil

Flowchart of structure modeling

•The deep underground structure from the crust and

plates up to seismic bedrock;

•The structure of sediments from the seismic bedrock

up to engineering bedrock (Vs=400m/s～700m/s);

•The structure of surface soils from the engineering

bedrock up to the ground surface.

Site Amplification 2005～2008 2009

Site Amplification Site Amplification

1km2 0.25×0.25km2

Mesh size Mesh size

390,000 meshes 5,960,000 meshes

Subsurface modeling of deep sedimentary layers

Vp 2.1km/s Vp 2.5km/s Vp 3.0km/s Vp 3.5km/s

Vp 4.0km/s Vp 4.8km/s Vp 5.5km/s

Initial

model.

Velocity-structure of deep sedimentary layers from the seismic bedrock to the engineering bedrock greatly affects the characteristics

of relatively long period strong-motion.

We developed a velocity structure model of deep sedimentary layers of the whole of Japan for evaluation of strong motion.

Velocity structure model for deep sedimentary layers

Depth contour of seismic bedrock

To improve the initial model, with a focus on

predominant periods, by comparing the H/V spectral

ratio of seismic records (for M5.5 or greater) obtained

by the Kyoshin Network (K-NET, KiK-net) and the

H/V spectral ratio of fundamental to 4th higher-mode

Rayleigh waves obtained from velocity structure

models.

Comparing calculated waveforms with observed

waveforms for middle-scale earthquakes (around M5),

the validity of adjustments using H/V spectral ratios

was reviewed.

Development of Integrated Geophysical and Geological Information Database

NIED

Database of

underground structure

AIST

Database of

geological information

Municipalitie’s

DB

PWRI

Database of

soil dynamics

JGS’s

database

Coordination and integration

by the network

9 9 9 9 9

0

00

00

00

00

00

000

500

000

500

000

500

000

500

000

500

000

500

000

000

Information on underground structure

Reduction of natural disaster

Construction of safe, secure and sustainable society

Management system on sharing for Integrated Database

ERI of

Tokyo University

Tokyo Institute of

Technology

Utilization of the database

The concept of Integrated Database

Integration by

shared management

via the network

Integration of databases of

multiple organizations

Integration of data

across the country

Integration in terms of

depth from the shallow

part to the deep part

Qualitative integration

of information on geology,

geophysical data, etc.

Integration of data

contents from the original data

to model data

Image of Integration

As we regards information on underground structure as ‘public assets of the nation’, we develop a

database that allows for mutual utilization and publication of data through a network of each

organization’s databases. The keyword of this research project is ‘Integration’. The word ‘Integration’

implies several meanings, as shown in this figure, the process of integration is to be carried out

following these six principles.

Diagram showing the concept of the management system on sharing

WMS: Web Map Service

WFS: Web Feature Service

Working group (Venue to discuss utilization and publication of data)

Service integration, Data integration Portal site （NIED）

User Search function, Map display function, Download

function

Image, GML Applicable software: Browser, GIS

AIST

Database

Spatial database

WMS server WFS server

Database B Database A

NIED (Head office)

Internal user

Existing system

Database

(Example: PostgreSQL)

Spatial database

(Example: PostGIS)

Spatial information

and attributes

WMS, WFS server

(Example: MapServer)

Upgrading adapter

Image, GML Image, GML Image, GML Image, GML

Spatial

information

and attributes Existing system

Upgrading adapter

Internal user

PWRI

Database

Spatial database


Database C

Spatial

information


Upgrading adapter

Internal user Database

Spatial database


Database D

Spatial

information


Upgrading adapter

Internal user

Municipality

The configuration of the data sharing management system consists of database management

servers for individual organizations and a portal site.

Boring data collected and registered into database

The number of borehole data which were

collected and registered into data base

Location map of boring data

which were collected and

registered into the database.

Organization NO. Detail Detail No.

MLIT 90,542 MEXT

（NIED） 51,950

Hokkaido area 11,242 Tohoku area 8,229 Kanto area 77,180

Hokuriku area 6,681 Chubu area 21,630 Kinki area 3,698

Shikoku area 100 Hokkaido 315 Tochigi 777 Chiba 2,196 Saitama 1,560 Kanagawa 24,098 Shizuoka 2,419 Niigata 169 Fukui 342 Ishikawa 4,201 Fukuoka 13

Academic societies 79,645 Public corporation 3,652

Geological maps, etc. 10,422 Total 401,061

Country 142,492

128,760 Prefecture

Municipality 36,090

Other 93,719

The number of boring data

that have been registered in

the database is approximately

400,000 across the country.

Japan Seismic Hazard Information Station

http://www.j-shis.bosai.go.jp

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.

Probabilities that seismic intensity exceeds the JMA scale 5-, 5+, 6- and 6+ in 30 or 50 years. The JMA seismic intensity corresponding to the exceedance probability of 3% and 6% in 30 years and of 2%, 5%, 10% and 39% in 50 years.


Example of display of site amplification factor

By changing the transmission rate, background map

can be emphasized.

GPS

WMSサービス

RestfulAPI

3G/WiFi

J-SHIS application for smart phone

Japanese-Chinese-Korean cooperative joint research

collaboration program

Title of cooperative research project (2010-2013)

Seismic Hazard Assessment for the Next Generation Map

Research Leaders

Hiroyuki Fujiwara (Japan, NIED)

Tao Xiaxin (China, Harbin Institute of Technology)

Myung-Soon Jun (Korea, KIGAM)

Cooperative joint research

1. To review the data and methodologies adopted in SHA maps of the three countries, and re-

evaluate and improve the SHA in each of the countries.

2. To compare the data and the methodologies with the state of the art, and see if there

anything could be accepted for the next generation maps.

3. To develop a procedure to establish ground motion equations for maps.

4. To combine the probabilistic seismic hazard assessment and the scenario seismic approach,

the latter is especially for near field of potential large earthquake.

Disaster-Risk Information Platform (BOSAI-DRIP)

Disaster-Risk Management

System for Individual

災危険度タ

危度大丈夫

自宅の登家族の登自宅耐震評価備蓄登ァイル編集表示ツルヘル

緊急震速報

風豪予想

災危険度タ

危度大丈夫


緊急震速報

風豪予想

……

……

Disaster-Risk Evaluation System

History and Record of Disaster

Interoperability of information

DRI for Earthquakes

DRI for Volcanic Eruption

DRI for Floods

DRI for Landslides

Universities, Institutes Governments

Companies, NPOs

Hazard Map Damage Assessment

Institutions and Services

Geospatial Information

Interoperable

Information Environment

DRMS for

LC

DRMS for

LC

Disaster-Risk Management

System for Local Community

Clearinghouse for DRI

DRMS for I

災危険度タ

危度大丈夫


緊急震速報

風豪予想

災危険度タ

危度大丈夫


緊急震速報

風豪予想

DRMS for I

災危険度タ

危度大丈夫


緊急震速報

風豪予想

災危険度タ

危度大丈夫


緊急震速報

風豪予想

I A U

“AIU(Japanese ABC)” for BOSAI-DRIP

DRI for Heavy Snow and Ice

Utiliz

ation o

f in

form

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Adva

ncem

ent of in

form

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Thank you for attention.

Documents

Seismic Hazard Assessment in Japan - J-SHIS … Hazard Assessment in Japan Hiroyuki Fujiwara National Research Institute for Earth Science and Disaster Prevention National seismic