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12/26/2004 Sumatra-Andaman Islands Earthquake. 3rd largest earthquake of the past 100 years (M w 9.3). Generated historically large tsunamis that struck Indonesia, Thailand, Sri Lanka, India, Africa that killed approximately 300,000 people. - PowerPoint PPT Presentation
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12/26/2004 Sumatra-Andaman Islands Earthquake
• 3rd largest earthquake of the past 100 years (Mw 9.3).
• Generated historically large tsunamis that struck Indonesia, Thailand, Sri Lanka, India, Africa that killed approximately 300,000 people.
• No effective warning of tsunami due to lack of monitoring/communication system in the Indian Ocean
Seismograms of the day: Global Seismic Displacement Wavefield, December 26, 2004.
Earth Simulator Sumatra Surface Wave Simulation
c/o Jeroen Tromp
0S0 - 20.5 minutes
0S3 - 35.6 minutes
0S2 - 53.9 minutes
Spheroidal Normal Modes
Very Large Earthquakes Significantly Excite the Planet’s Normal Modes
The Sumatra-Andaman
rupture was significant, even on the scale of the
entire planet.
c/o Miaki Ishii
The Sumatra-Andaman rupture was complex and distributed over more than 7 minutes.
Global Moment Release (1906-2005)
Chile (1960)
Alaska (1964)
Sumatra (2004)
“Great” earthquake are very significant global events.
…seismic Momentis proportionalto fault areatimes fault slip
Global Moment Release (1906-2005)
Approximately half of all earthquake moment release on the planet over the past 100 years occurred in just three earthquakes (a manifestation of power law statistics)!
Physics of Water Waves
Waves are the response of a liquid to departures from gravitational equilibrium.
•Wind waves in the deep ocean: Wavelength << water depth
•Tsunami waves in the deep ocean: Wavelength >> water depth
Wind Waves (away from shore)
Tsunamis in the deep ocean
c/o Steve Ward
Global Tsunami Simulation