J-RAPID Symposium March 6 - 7, 2013

Seismic Activity and Crustal Deformation after the 2011 Off the Pacific Coast of

Tohoku Earthquake

Y. Honkura Tokyo Institute of Technology

Japan Science and Technology Agency

Off the Pacific Coast of Tohoku Earthquake 2011 Mw9.0

World Seismicity Map

1952 Mw9.0

1957 Mw9.1

2004 Mw9.0

1964 Mw9.2

2010 Mw8.8

1964 Mw9.5

Earthquake research Institute, Univ. Tokyo

Aftershock Area and Seismicity Triggered by the Mainshock

3/11

3/11

3/9

3/11

3/11

3/12

3/12

3/15

3/23

4/11 4/7

Japan Meteorological Agency

Aftershock Activity during Two Years

Japan Meteorological Agency

M7.4

M7.5

M7.2

M7.3

M7.0

M7.6

M7.3

M9.0

Seismicity around the Aftershock Area during Two Years

Japan Meteorological Agency 2/25 2013

M6.3

Co-seismic Crustal Deformation (GEONET)

T Nishimura et al., Earth Planets Space, 63, 631-636, 2011

New Technology for More Accurate Long-Term Forecast of Subduction-Zone Earthquakes

GPS/Acoustic Seafloor Geodetic Observations

Japan Coast Guard

Pre- and Co-seismic Crustal Displacements

M. Sato, Japan Coast Guard

134°E 136°E 138°E 140°E 142°E 144°E 146°E32°N

34°N

36°N

38°N

40°N

5cm/year

Steady Crustal Movements Caused by Subduction of Oceanic Plates

Japan Coast Guard

Tohoku Univ. Nagoya Univ.

Pacific Plate

Philippine Sea Plate

9.2cm/year (NUVEL-1A)

Approx. 4cm/year (Kotake et al.，1998)

The velocity vectors detected by GPS/acoustic seafloor geodetic observations are generally consistent with those detected by on-land GPS measurements.

(vs Eurasian plate)

M. Sato, Japan Coast Guard

Co-seismic Displacement off the Coast of Miyagi Prefecture

Sato et al., Science, 19 May 2011

Co-seismic Fault Slip Model of GSI

Geospatial Information Authority of Japan

Estimated vertical displacement estimated from the model

Post-seismic Crustal Deformation (GEONET)

Geospatial Information Authority of Japan

Post-seismic Fault Slip Model (GEONET)

Geospatial Information Authority of Japan

Cumulative Seismic Moment Equivalent to Post-seismic Crustal Deformation

March 12, 2001 – January 12, 2013

Geospatial Information Authority of Japan

Headquarters for Earthquake Research Promotion Director: Minister of Education, Culture, Sports, Science and Technology

Japan Agency for Marine-Earth Science and Technology (JAMSTEC)

National Research Institute of Fire and Disaster

National institute of Information and Communications Technology (NICT)

National Institute of Advanced Industrial Science and Technology (AIST)

Universities

Japan Coast Guard

Japan Meteorological Agency (JMA)

Geographical Survey Institute (GSI)

National Research Institute for Earth Science and Disaster Prevention (NIED)

Ministry of Education, Culture, Sports, Science and technology (MEXT)

① Planning of comprehensive and basic policies ② Coordination of budgets and other administrative works with related governmental organizations ③ Establishment of comprehensive survey and observation plans ④ Collection, arrangement, analysis and comprehensive evaluation of survey results by related governmental organizations, universities, etc. ⑤ Public announcements based on the comprehensive evaluations

Policy Committee Earthquake Research Committee

16

National Seismic Hazard Maps for Japan

The promotion of earthquake research－comprehensive and basic policy for the promotion of earthquake observations, surveys, measurements, and researches –

Survey of Underground Structures Research of Active Faults Survey and Observation of Earthquakes

Long-term Evaluation of the Occurrence of Earthquakes Improvement of Methods to Evaluate( Predict) Strong Ground Motions

Probabilistic Seismic Hazard Map The probability of ground motions equal to or higher than seismic intensity 6 Lower, occurring within 30 years from the present.

Seismic Hazard Map for Specified Seismic Source Faults The seismic intensities forecast for various regions around the Miura-hanto fault group.

Seismic intensity These maps are expected to be used ○to raise the public's awareness of earthquake disaster reduction ○to take the earthquake disaster reduction measures more effectively and efficiently ○to evaluate the risks of establishing important facilities and enterprises in a certain area.

4 5 5 6 6 Lower Upper Lower

Upper or above

National Tsunami Hazard Map Plan of HERP

Earthquakes in Japan Sea

Earthquakes along Japan Trench

Earthquakes along Japan Trench Earthquakes along

Nankai Trough

Ministry of Education, Culture, Sports, Science and Technology (MEXT)

☆ Epicenter of Main Shock

Ｅｐｉｏ

Distribution of Hi-net and F-net Seismic Stations

HERP (MEXT)

Plate subduction

Seafloor Cable Network Plan of MEXT

Seismometers Pressure Gauges

・Seismic Observations to improve earthquake early warning ・Pressure Measurements to monitor vertical movement of

seafloor and improve tsunami warning

Ministry of Education, Culture, Sports, Science and Technology (MEXT)

New Tsunami Warning System of JMA

Japan Meteorological Agency http://www.seisvol.kishou.go.jp/eq/eng/tsunami/tsunamiwarning_leaflet.pdf