HR: 0800h
AN: S41A-0940    [Abstracts]
TI: From Slip to Stress - A Shortcut
AU: * Ripperger, J
EM: ripperger@sed.ethz.ch
AF: Institute of Geophysics, ETH Zurich, Schafmattstr. 30, Zurich, 8093 Switzerland
AU: Mai, P M
EM: mai@sed.ethz.ch
AF: Institute of Geophysics, ETH Zurich, Schafmattstr. 30, Zurich, 8093 Switzerland
AB: One of the fundamental quantities for studying earthquake dynamics is the static stress change on the fault plane. Being able to reliably estimate the stress change distribution is required in modeling the dynamic rupture of past earthquakes, but also allows to constrain the temporal evolution and the energy budget of earthquake rupture in scenario earthquakes with synthetic slip maps (e.g. for strong-motion simulations). In order to compute the distribution of stress changes on the fault plane from the distribution of static displacements, several numerical methods are in use today, but most of them come at rather high computational cost. I this study we extend the spectral approach developed by Andrews (1980) to account for both slip-parallel and slip-perpendicular stress changes and compare it against existing analytical formulations. We present calculations for slip maps of past earthquakes and find that the resulting stress changes are accurate to about 1-2% of the maximum absolute stress change, while the computation time is greatly reduced. Our method therefore provides a reliable and fast alternative to other approaches. In particular, its speed enables the efficient computation of stress drop distributions for large suites of simulated/inferred slip models, thus facilitating the construction of physically consistent source characterizations for near-source strong-motion simulations. Our tool may also be useful for on-fault Coulomb-stress-change calculations in the case of heterogeneous slip.
DE: 7260 Theory and modeling
DE: 7209 Earthquake dynamics and mechanics
DE: 3210 Modeling
DE: 3230 Numerical solutions
SC: Seismology [S]
MN: 2004 AGU Fall Meeting