HR: 12:05h
AN: U22A-07    [Abstracts]
TI: Inversion of satellite altimetry data to recover the Sumatra 2004 earthquake slip distribution
AU: * Sladen, A
EM: anthony.sladen@cea.fr
AF: Laboratoire de Détection Géophysique CEA/DASE, BP12, Bruyeres-le-Chatel, 91680 France
AU: Hebert, H
EM: helene.hebert@cea.fr
AF: Laboratoire de Détection Géophysique CEA/DASE, BP12, Bruyeres-le-Chatel, 91680 France
AB: The great Sumatra tsunami of 26 December 2004 confirmed the possibilities of measuring the wave heights using satellite altimetry. Although these are not the first observations of the kind, they are the first quality data sets (signal to noise ratio ten times better than any previous observation) that can be used to study propagation effects and sources parameters without the need to take into account the strongly non-linear coastal effects. We focus on the earthquake source assuming linear earthquake-tsunami coupling and propagation. This linearization allows us to generate Green functions for different parts of the fault plane and to invert for their relative contribution to the altimetry waveforms. We estimate the validity of our approach through synthetic tests and check if the problem is well-posed. Our final solution is in very good agreement with recent GPS and seismological studies with two main asperities releasing energy: the strongest being localized at the latitude of Aceh and the second around the island of Car Nicobar. Finally, we compute a forward model of this solution and compare it with tide gauges records available around the Indian Ocean.
DE: 4534 Hydrodynamic modeling
DE: 4564 Tsunamis and storm surges
DE: 7240 Subduction zones (1207, 1219, 1240)
DE: 9340 Indian Ocean
SC: Union [U]
MN: Fall Meeting 2005