The role of horizontal impulses of the faulting continental slope in generating the 26 December 2004 tsunami
Por:
Song Y.T., Fu L.-L., Zlotnicki V., Ji C., Hjorleifsdottir V., Shum C.K., Yi Y.
Publicada:
1 ene 2008
Resumen:
For a long time, people have believed that the vertical displacement of seafloor due to undersea earthquakes is the primary cause of tsunami genesis. However, seismically-inverted seafloor deformation of the 2004 Sumatra-Andaman earthquake shows that the total vertical displacement is not enough to have generated the powerful Indian Ocean tsunami. Based on the seismically-inverted data and a three-dimensional ocean general circulation model (OGCM), we show that the momentum force, transferred by the horizontal impulses of the faulting continental slope in that earthquake, has accounted for two thirds of the satellite-observed tsunami height and generated kinetic energy 5 times larger than the potential energy due to the vertical displacement. The asymmetric tsunami pattern, recorded by tide-gauges showing leading-elevation waves toward Sri Lanka and leading-depression waves toward Thailand, is best explained by the horizontally-forced mechanism. The same mechanism has also explained the March 2005 Nias earthquake and tsunami data, suggesting that the horizontal motions of faulting have played more important roles in tsunami genesis than previously thought.
Filiaciones:
Song Y.T.:
NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, CA 91109, United States
Fu L.-L.:
NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, CA 91109, United States
Zlotnicki V.:
NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, CA 91109, United States
Ji C.:
Department of Earth Science, University of California, Santa Barbara, CA 93106, United States
Hjorleifsdottir V.:
Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, United States
Shum C.K.:
School of Earth Sciences, Ohio State University, Columbus, OH 43210, United States
Yi Y.:
School of Earth Sciences, Ohio State University, Columbus, OH 43210, United States
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