HR: 1340h
AN: S13D-1089    [Abstracts]
TI: Multi-resolution extension of Spectral Elements to non smooth dynamics: earthquake rupturing process
AU: * Festa, G
EM: festa@ipgp.jussieu.fr
AF: D\'epartement de Sismologie Institut de Physique du Globe de Paris, 4 Place Jussieu, Paris, 75252 France
AU: Delavaud, E
EM: delavaud@ipgp.jussieu.fr
AF: D\'epartement de Sismologie Institut de Physique du Globe de Paris, 4 Place Jussieu, Paris, 75252 France
AU: Vilotte, J
EM: vilotte@ipgp.jussieu.fr
AF: D\'epartement de Sismologie Institut de Physique du Globe de Paris, 4 Place Jussieu, Paris, 75252 France
AB: Spectral element method (SEM) already proved to be a powerful tool for the simulation of the seismic waves at regional and global scales. For smooth dynamics, the SEM actually combines the geometrical flexibility of the finite elements with the exponential convergence rate, proper to high-order spectral techniques. Extension to non smooth dynamics, such as faulting process and short wave radiation, requires specific solutions. We present here these main extensions in order to solve earthquake dynamic rupturing for realistic fault geometries and complex geological media. First, a new second-order time stepping allowing an implicit solution of the non-smooth contact and frictional conditions on faults of arbitrary shape is discussed and shown to be rather effective. Second, consistent high frequency dissipation is added to the SEM through a complex prolongation of the elastodynamics Green's functions. This leads to a selective absorption of the high-frequencies within a finite thickness fault zone. Finally, a multiresolution strategy has been developped by extending the non conforming Mortar method in space to a non conforming matching condition for domains with different space and time steps. Such a solution will allow to accurately resolve the high-frequencies generated during the rupturing process in the vicinity of the fault and to propagate the low-frequency field away from the fault itself to the receivers. The efficiency of these extensions is quantitatively addressed by several examples that will be discussed. This work is part of the SPICE European Project Festa, G., and Vilotte, J.-P., Efficient PML for Spectral element methods, Submitted to J. Geophys. Int. Festa, G., Vilotte, J.-P. and Ampuero, J.-P., Dynamic rupturing within Spectral elements, Submitted to Bull. Seism. Soc.Am.
DE: 7260 Theory and modeling
DE: 7203 Body wave propagation
DE: 7209 Earthquake dynamics and mechanics
SC: Seismology [S]
MN: 2004 AGU Fall Meeting