HR: 15:10h
AN: S53C-07    [Abstracts]
TI: Frequency Domain Inversion of Strong Motions: Application to the Blind Test for Kinematic Source Inversion (EC-project SPICE)
AU: * Causse, M
EM: mathieu.causse@obs.ujf-grenoble.fr
AF: LGIT, Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AU: Cotton, F
EM: fabrice.cotton@obs.ujf-grenoble.fr
AF: LGIT, Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AU: Campillo, M
EM: Michel.Campillo@ujf-grenoble.fr
AF: LGIT, Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AB: We have applied a frequency domain inversion method to the Blind Test for Kinematic Source Inversion (Mai et al., EC-project SPICE). The parameters describing the rupture process are the local slip, the rupture time and the rise time. Green's functions are numerically evaluated with the Discrete Wavenumber Method. A Generalized Least Square Inversion is used to retrieve the final source parameters. The inversion procedure is based on an iterative Quasi Newton Algorithm (Tarantola and Valette, 1982). A spatial smoothing constraint is introduced through the covariance matrice of the parameter space vector to prevent from unrealistic slip value bumps between two neighbouring subfaults. The resolution matrice illustrates how well the inverse problem can be solved by the data. The values of the resolution are used in a relative way to compare the resolution of different parts of the fault. Since the problem is intrinsically nonlinear the final results depends on the a priori chosen initial parameterization. In order to analyze the non-uniqueness of the solution, we therefore test a population of starting models.
DE: 0550 Model verification and validation
DE: 3260 Inverse theory
DE: 7215 Earthquake source observations (1240)
SC: Seismology [S]
MN: 2007 Fall Meeting