HR: 0800h
AN: S21A-0271    [Abstracts]
TI: Fast Teleseismic Bodywave Inversion Of Intermediate And Deep Earthquakes Source Parameters: Combining Simulated Annealing With Linear Inversion
AU: * Tocheport, A
EM: audrey@eost.u-strasbg.fr
AF: EOST-IPGS, 5 rue Rene Descartes, Strasbourg, 67084 France
AU: Luis, R
EM: luis@sismo.u-strasbg.fr
AF: EOST-IPGS, 5 rue Rene Descartes, Strasbourg, 67084 France
AU: Chevrot, S
EM: Sebastien.Chevrot@cnes.fr
AF: OMP, 14 Avenue Edouard Belin, Toulouse, 31400 France
AB: We develop an inversion algorithm to extract source parameters: Moment Tensor and Source Time Function, from a set of teleseismic bodywave records for intermediate and deep earthquakes. The method proceeds in two stages. First, a non linear inversion is performed (a) to align in time the set of waveforms, (b) to determine a common source time function and (c) to recover a collection of observed station amplitudes. The nonlinear inversion is made with the simulated annealing technique. Those results are then used, in the second stage as \textit{secondary observables} and a standard linear inversion is made to estimate the complete moment tensor as well as the corresponding errors. All of the calculations are extremely simple and, in particular, it is not necessary to compute synthetic seismograms. The present state of the method requires well isolated phases at different stations, which restricts its application to intermediate and deep events. The algorithm is applied to the FDSN broadband records corresponding to the period 1993-2003 of worldwide intermediate and deep seismicity. The moment tensors thus obtained are then systematically compared to the Harvard-CMT solutions.
DE: 8124 Earth's interior--composition and state (old 8105)
DE: 7203 Body wave propagation
DE: 7209 Earthquake dynamics and mechanics
DE: 7215 Earthquake parameters
SC: Seismology [S]
MN: 2004 AGU Fall Meeting