HR: 12:05h
AN: S32B-08    [Abstracts]
TI: Spectral Element simulation of rupture dynamics on curvilinear faults
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
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
AB: Numerical simulation of fault rupturing process requires today the resolution of several time and space scales, to capture the nucleation, the rupture front propagation, and the short wave radiation associated with heterogeneous fault systems of complexgeometries. Two classes of methods are usually used in seismology: finite differences and boundary integral equations. Classical mixed formulation of finite differences suffers from smoothing and smearing of the rupture front due to the inherent interpolation of staggered schemes. Although if extensions to curved faults have recently been proposed (Cruz-Atienza and Virieux, 2004), using Saenger's stencils, up to now applications of FD methods have been mostly restricted to planar faults. On the other hand, boundary integral equations (Andrews, 1976; Fukuyama and Madariaga, 2000) have been shown to accurately model 3D curvilinear fault segments but are is restricted to homogeneous or layered elastic media. A important issue, still be correctly resolved is the physics of the rupture propagation when reaching the surface. In this framework, Spectral Element method, combining both the geometrical flexibility of finite elements and convergence rate of high-order spectral methods is an attractive tool for numerical simulation of earthquake dynamic rupturing on realistic fault segments in complex geological media. We present numerical simulations of 2D inplane dynamic faulting using the SE method. The results are discussed paying a special attention to the sub- to super-shear transition for both planar and non planar faults, to the influence of different frictional laws on the rupture propagation and to the influence of layered geolgical media both on the dynamics of the rupture process and the short wave radiation. On going work on two main extensions will be discussed : interactions as the faulting process reach the surface and 3D geometries of faults.
DE: 7260 Theory and modeling
DE: 7209 Earthquake dynamics and mechanics
SC: Seismology [S]
MN: 2004 AGU Fall Meeting