Pelatihan :
Techniques in Active Tectonic Study
Juni 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 Earthquake
http://www.nature.com/ngeo/journal/v1/n11/fig_tab/ngeo341_F1.html
Magnitude 9.0 NEAR THE EAST COAST OF HONSHU, JAPAN
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.
.In downtown Tokyo, large buildings shook violently and there was
severe flooding due to a tsunami generated by the earthquake.
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
USGS
Magnitude 9.0 NEAR THE EAST COAST OF HONSHU, JAPAN
Friday, March 11, 2011 at 05:46:23 UTC
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.
The tsunami, seen crashing into
homes in Natori, Miyagi prefecture. AP
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
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/
Foreshocks, Mainshock, Aftershocks
Movie 2.5
http://eqseis.geosc.psu.edu/~cammon/Japan2011EQ/
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 propagation
http://www.iris.edu/hq/retm/#1328;
Simple view of the seismic wave propagation
http://www.iris.edu/hq/retm/#1328;
Seismic wave propagation
http://www.iris.edu/hq/retm/#1328;
Seismic 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
Tohoku, Japan Earthquake: Shaking Duration in Tokyo, Ground Velocity
6 minutes
Videos from Tokyo and nearby
• http://www.youtube.com/watch?v=oQVPfQu
50yY –EEW works!
• http://www.youtube.com/watch?v=dN4NBK1
veb0 –train stopped
• http://www.youtube.com/watch?v=64PEo29h
BGY –Tokyo skyscrapers swaying
http://tremblingearth.wordpress.com/2011/03
/13/more-unique-perspectives-of-the-8-9quake/
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 meters
japan = mu.*500.*km.*200.*km.*11 =
3.3000e+022 Nm
japan_mw=(2./3).*log10(japan)-6 =
9.0123
M Simons et al. Science 2011;332:1421-1425
Evolving displacement field
http://gps.alaska.edu/ronni/sendai2011.html
acquired February 26, 2011
http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=49630
acquired March 12, 2011
Coastal inundation and permanent subsidence (?)
http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=49630
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
Backprojection of seismic energy to source
USArray
Dense Euro
http://www.tectonics.caltech.edu/slip_history/2011_taiheiyo-oki/Backprojection/
Ide, et al., 2011
Coulomb calculation
Coulomb calculation
Lay and
Kanamori, 2011
Lay and
Kanamori, 2011
Ando and Imanishi, 2011
Foreshock-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_j
ishincategory.pdf modified: http://home.hiroshimau.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