Pelatihan :

Techniques in Active Tectonic StudyJuni 20-Juli 2, 2013

Instruktur: Prof. J Ramon Arrowsmith (JRA)Dari Arizona State University (ASU) - US

Tempat Pelaksanaan: Ruang Pangea, Laboratorium Gempabumi (LabEarth) – Puslit Geoteknologi LIPI dan Kuliah lapangan akan

dilakukan disekitar Sesar Lembang, Jawa Barat.

* Lebih jelas baca TOR/KAK dan daftar acara

Subduction I: Japan 2011 earthquake

Outline of this lecture

• Seismicity• Seismic waves• Displacements on land and seafloor• Source models• Seismic coupling• Comparison with other events

March 11, 2011 Tohoku, Japan M9.0 EarthquakeMarch 11, 2011 Tohoku, Japan M9.0 Earthquake

http://www.nature.com/ngeo/journal/v1/n11/fig_tab/ngeo341_F1.html

Magnitude 9.0 NEAR THE EAST COAST OF HONSHU, JAPANMagnitude 9.0 NEAR THE EAST COAST OF HONSHU, JAPANFriday, March 11, 2011 at 05:46:23 UTC Friday, March 11, 2011 at 05:46:23 UTC

Japan was struck by a magnitude 9.0 earthquake off its northeastern coast Friday March 11, 2011. This is one of the largest earthquakes that Japan has ever experienced.

. USGS

Part of houses swallowed by

tsunami burn in Sendai, Miyagi

Prefecture (state) after Japan was

struck by a strong earthquake off its

northeastern coast Friday, March 11,

2011.

New York Times

In downtown Tokyo, large buildings shook violently and there was severe flooding due to a tsunami generated by the earthquake.

Tsunami waves swept away houses and cars in northern Japan and pushed ships aground.

The tsunami waves traveled far inland, the wave of debris racing across the farmland, carrying boats and houses with it.

Houses were washed away by tsunami in Sendai, Miyagi Prefecture in eastern Japan, after Japan was struck by a magnitude 9.0 earthquake off the northeastern coast.

New York Times

Magnitude 9.0 NEAR THE EAST COAST OF HONSHU, JAPANMagnitude 9.0 NEAR THE EAST COAST OF HONSHU, JAPANFriday, March 11, 2011 at 05:46:23 UTC Friday, March 11, 2011 at 05:46:23 UTC

The tsunami, seen crashing into homes in Natori, Miyagi prefecture. AP

March 25, 2011 estimates:10,066 people confirmed dead and 17,443 people are reported missing>$300B economic losses

Seismicity of northern Japan since 1973 http://eqseis.geosc.psu.edu/~cammon/Japan2011EQ/

http://eqseis.geosc.psu.edu/~cammon/Japan2011EQ/

Foreshocks, Mainshock, AftershocksForeshocks, Mainshock, Aftershocks

Movie 2.5

Japan 2011 Aftershocks http://eqseis.geosc.psu.edu/~cammon/Japan2011EQ/

Tohoku, Japan Earthquake: Aftershock (and Foreshock) Sequence, 03/08/11 - 03/16/11

Tohoku, Japan Earthquake: Aftershock (and Foreshock) Sequence, M:Time History

Simple view of the seismic wave propagationSimple view of the seismic wave propagation

http://www.iris.edu/hq/retm/#1328;

Simple view of the seismic wave propagationSimple view of the seismic wave propagation

http://www.iris.edu/hq/retm/#1328;

Seismic wave propagationSeismic wave propagation

http://www.iris.edu/hq/retm/#1328;

Seismic wave propagationSeismic wave propagation

http://www.iris.edu/hq/retm/#1328;

Tohoku, Japan Earthquake: Shaking Duration in Tokyo, Ground Acceleration

1g = 9.8e+002 gal

+/-17%g

6 minutes

Tohoku, Japan Earthquake: Shaking Duration in Tokyo, Ground Velocity

Videos from Tokyo and nearby

• http://www.youtube.com/watch?v=oQVPfQu50yY –EEW works!

• http://www.youtube.com/watch?v=dN4NBK1veb0 –train stopped

• http://www.youtube.com/watch?v=64PEo29hBGY –Tokyo skyscrapers swaying

http://tremblingearth.wordpress.com/2011/03/13/more-unique-perspectives-of-the-8-9-quake/

Tohoku, Japan Earthquake: Finite Fault Model USGS V1 - 7 hrs after OT•Compact rupture, mostly bilateral about epicenter, peak slip up dip of hypocenter.•Rupture was likely restricted to the shallow trench, and GPS vectors suggest slip did not reach the plate boundary beneath the coastline.•Peak slips closer to 40+ m, inferred from updated modeling. •Box is 580 km long and 190 km wide•Zone of main slip is 300 km long and ~150 wide

•M0= mu*A*u_bar-mu = 30 GPa (3x1010 N/m2)-A is surface area that slipped (m2) [width x length]-u_bar is the average slip in metersjapan = mu.*500.*km.*200.*km.*11 = 3.3000e+022 Nmjapan_mw=(2./3).*log10(japan)-6 = 9.0123

M Simons et al. Science 2011;332:1421-1425

Evolving displacement fieldEvolving displacement field

http://gps.alaska.edu/ronni/sendai2011.html

acquired February 26, 2011

http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=49630

http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=49630

Coastal inundation and permanent subsidence (?)

acquired March 12, 2011

http://www1.kaiho.mlit.go.jp/e/KAIYO/image/Seafloor_Geodetic_Observation.gif

Sato, et al., 2011

M Simons et al. Science 2011;332:1421-1425

USArray

http://www.tectonics.caltech.edu/slip_history/2011_taiheiyo-oki/Backprojection/

Dense Euro

Backprojection of seismic energy to source

Ide, et al., 2011

Coulomb calculation

Coulomb calculation

Lay and Kanamori, 2011

Lay and Kanamori, 2011

Ando and Imanishi, 2011Foreshock-Mainshock linkage

Lay and Kanamori, 2011

Lay and Kanamori, 2011

Japanese subduction zone segmentation and hazard assessment:

Expectation was for individual patches to rupture (M~8—consistent with historic behavior). Tsunami hazard was based on last few centuries record.

http://www.jishin.go.jp/main/chousa/10_yosokuchizu/k_jishincategory.pdf modified: http://home.hiroshima-u.ac.jp/kojiok/110311EQ/HERPmapwithnotes1.pdf

Subduction I: Japan 2011 earthquake

Outline of this lecture

• Seismicity• Seismic waves• Displacements on land and seafloor• Source models• Seismic coupling• Comparison with other events