china and earthquake - 日本学術振興会 areas of china areas of the world 33% 55% death toll in...

China and Earthquake

BAI Ling (白玲バイリン)JSPS F ll U i i f T kJSPS Fellow, University of Tokyo

JSPS science dialogue @ Seiryo High School

P t I E th k C t Chi• Part I Earthquake Country‐China地震大国ー中国地震大国ー中国

• Part II waveform analysisPart II waveform analysis

波形の解析


ChinaChina

• Capital: Beijing

• Area: 9.6 million km²Area: 9.6 million kmAbout 25 times larger than Japan

P l ti 1 3 billi• Population: 1.3 billionAbout 10 times more than Japan


Seismicity of the world世界震源地図世界震源地図

JSPS science dialogue @ Seiryo High School(from Univ. of Tokyo and Tokyo Cartographic Co.)

7%

Areas of ChinaAreas of the World

33%

55%

Death toll in ChinaContinental quakes in ChinaContinental quakes in the World

by earthquakes Death toll in the world by earthquakesy q


What is an earthquakeWhat is an earthquake

Earthquake=Earth+quake:the result of a sudden release of energythe result of a sudden release of energy

in the Earth's crust that creates seismic wavesJSPS science dialogue @ Seiryo High School

Zhang Heng張衡張衡

(A.D.78-139)

Houfeng SeismographHoufeng Seismographou e g Se s og ap候風地動儀

ou e g Se s og ap候風地動儀

John Milne(1850-1913)

The first modern seismograph1880


How does the earthquake occur地震はどのようにして起こるのかはどのようにして起こるのか

Eurasia Plate

North American Plate

Pacific plate

Eurasia Plate

Philippine Sea PlateIndian Plate

Philippine Sea Plate

The surface of the earth is covered with PLATESJSPS science dialogue @ Seiryo High School

(from Univ. of Tokyo and Tokyo Cartographic Co.)

Plate tectonicsプレートテクトニクスプレトテクトニクス


① Interplate Earthquakeプレート境界型地震プレト境界型地震


Interplate Earthquakes around Japan日本付近のプレート境界型地震日本付近のプレト境界型地震


② Intraplate Earthquakeプレート内地震プレト内地震


The 2008 Sichuan, China earthquakeq

FaultLocation

A bank building Rain and rock slides JSPS science dialogue @ Seiryo High School

Intraplate Earthquakes in Japan日本での地殻内地震日本での地殻内地震

2003 宮城県北部の地震(M6.2)2008 岩手・宮城内陸地震(M7.2)

2004 新潟県中越地震(M6.8)

2003 宮城県北部の地震(M6.2)

2007 新潟県中越沖地震(M6.8)2007 能登半島地震(M6.9)

2000 鳥取県西部地震 (M7.3)1995 兵庫県南部地震 (M7.3)


intraplate earthquake: movement of faultプレト内地震断層でのすべり運動プレート内地震: 断層でのすべり運動

• Normal Fault 正断層 • Reverse (Thrust) Fault 逆断層：

Hanging wallfoot wall

• Strike‐Slip Fault横ずれ断層


Earthquake faults that appear in surface of the earth地表に現れた地震断層

• Nojima fault: 1995 Kobe eq N d i f lt 1891 N bi• Nojima fault: 1995 Kobe eq • Neodani fault:1891 Nobi eq

• 2008 Sichuan eq • Denali fault:2002 Denali eq

Comparison of two types of earthquakes二種類の地震の比較

I t l t I t l t

二種類の地震の比較

Interplate Intraplate

Location The boundary between two plates Interior of a plate with active fault

Period Tens to hundreds years Thousands to ten thousands years

Magnitude M８～M９ M７～M８

Disaster Tsunami Direct hit

Examples ・ 2004 Sumatra earthquake・ 1944 Tonankai earthquake・ The expected Nankai earthquake

・ 2008 Sichuan, China earthquake・ 2008 Iwate‐Miyagi inland earthquake


Conclusion 1

・ Plates are moving・ Plates are moving

1.g

・ Interplate earthquakeg

・ Interplate earthquake

22.

Sli f f ltSli f f lt2.・Slip of fault・Intraplate earthquake・Slip of fault・Intraplate earthquake

Q: How to study the earthquake that occur in the deep area of the Earth.


P t I E th k C t Chi• Part I Earthquake Country‐China地震大国ー中国地震大国ー中国

• Part II waveform analysisPart II waveform analysis

波形の解析


Size of shakeWaveform 波形

① jump

Size of shake

① j p

② t i② train

③ earthquake

10 minutes time JSPS science dialogue @ Seiryo High School

Waveforms recorded by a station at Taiwan地震波記録の例（台湾の観測点）地震波記録の例（台湾の観測点）

Surface waveSize of shake

Iwate・Miyagi inland eq P wave S wave

Surface wave

P wave S wave

Surface wave

Sichuan, China eqP wave S wave

timeJSPS science dialogue @ Seiryo High School

P wave

S wave

Surface wave


Distance to hypocenter震源までの距離震源までの距離

Distance =(Ts-Tp)*8

Earthquake early warning to announce before the arrival of strong tremorsJSPS science dialogue @ Seiryo High School

Analysis of earthquake fault震源断層の解析

Observed waveforms Theoretical (black) and observed (red)

震源断層の解析① ③

Supposed fault②Supposed fault


The 2008 Iwate ・Miyagi inland earthquake2008年岩手・宮城内陸地震2008年岩手・宮城内陸地震

Surface of the Earth

Width (W): ~20kmColor: amount of slip (D)

（largest: ~3m）

Length of fault (L): ~40km

Moment magnitude：Mw= μ×D×L×W 6.8Mw μ D L W 6.8


The 2008 Sichan, China earthquake2008年中国四川地震2008年中国四川地震

~40km

~250km

0

10m!

Mw 7.9


One difference in magnitude…マグニチュードが１違うと．．．マグニチュドが１違うと．．．

10km

M 6.0 0.5m

1.5mM 7.0

30km

M 8.0

5m

100kmOne difference in magnitude

Area of fault： ~10 timesAmount of slip: ~3 times} Released energy: ~30 times

g


The size of the fault of Sichuan eq in Japan map四川地震の断層の大きさを日本で考えると四川地震の断層の大きさを日本で考えると

長野

東京名古屋


Conclusion 1

・ Plates are moving・ Plates are moving

1.

・ Interplate earthquake・ Interplate earthquake

・Slip of faultl h k

・Slip of faultl h k

2.

・Intraplate earthquake・Intraplate earthquake

3.・ waveform analysisL ti f th k

・ waveform analysisL ti f th k・Location of earthquake

・Focal mechanism・Location of earthquake・Focal mechanism

Document creation cooperation: Outreach Office of ERI, Univ. of Tokyo

china and earthquake - 日本学術振興会 areas of china areas of the world 33% 55% death toll in...

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