HR: 16:15h
AN: S34A-02    [Abstracts]
TI: Spectral Element Simulations of Rupture Dynamics along kinked faults
AU: * Vilotte, J
EM: vilotte@ipgp.jussieu.fr
AF: Laboratoire de Sismologie, Institut de Physique du Globe de Paris, 4 place Jussieu, Paris, 75252 France
AU: Festa, G
EM: festa@ipgp.jussieu.fr
AF: Laboratoire de Sismologie, Institut de Physique du Globe de Paris, 4 place Jussieu, Paris, 75252 France
AU: Madariaga, R
EM: madariag@geologie.ens.fr
AF: Laboratoire de Geologie, Ecole Normale Superieure, 24 rue Lohmond, Paris, 75232 France
AB: Numerical simulation of earthquake source dynamics provides key elements for ground-motion prediction and insights into the physics of dynamic rupture propagation. Faulting is controlled by non-linear frictional interactions and damage within the fault zone. Important features of the earthquakes dynamics, such as rupture velocity, arrest phase and high-frequency radiation are believed to be strongly influenced by the geometry of the faults (kinks, jogs and forks). Data analysis as well as kinematic inversions have pointed out potential links between super-shear and geometry, as in the case of the Denali and Izmit earthquakes. Finally, recent laboratory experiments of sub- and super-shear rupture propagation along kink interfaces have shed new lights on these phenomena. We present here spectral element simulations of the dynamic rupture propagation along kinked and curved fault interfaces, a problem that has been experimentally investigated by Rousseau and Rosakis (2003). Depending on the state of the initial stress, we numerically analyze the mechanics of the dynamical fault branching for sub- and super-shear rupture propagation. Special interest is devoted to source directivity effects and high frequency generation related to the branching process. Implications for strong motion analysis will be discussed. This work was supported by the SPICE - Research and Training project
DE: 0500 COMPUTATIONAL GEOPHYSICS (3200, 3252, 7833)
DE: 7209 Earthquake dynamics (1242)
DE: 7260 Theory
SC: Seismology [S]
MN: Fall Meeting 2005