HR: 13:55h
AN: S42F-02 INVITED     [PDF]
TI: Simulations of Ground Motion in Southern California based upon the Spectral-Element Method
AU: * Tromp, J
EM: jtromp@gps.caltech.edu
AF: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125
AU: Komatitsch, D
EM: komatits@gps.caltech.edu
AF: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125
AU: Liu, Q
EM: lqy@gps.caltech.edu
AF: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125
AB: We use the spectral-element method to simulate ground motion generated by recent well-recorded small earthquakes in Southern California. Simulations are performed using a new sedimentary basin model that is constrained by hundreds of petroleum industry well logs and more than twenty thousand kilometers of seismic reflection profiles. The numerical simulations account for 3D variations of seismic wave speeds and density, topography and bathymetry, and attenuation. Simulations for several small recent events demonstrate that the combination of a detailed sedimentary basin model and an accurate numerical technique facilitates the simulation of ground motion at periods of 2 seconds and longer inside the Los Angeles basin and 6 seconds and longer elsewhere. Peak ground displacement, velocity and acceleration maps illustrate that significant amplification occurs in the basin. Centroid-Moment Tensor mechanisms are obtained based upon Pnl and surface waveforms and numerically calculated 3D Frechet derivatives. We use a combination of waveform and waveform-envelope misfit criteria, and facilitate pure double-couple or zero-trace moment-tensor inversions.
DE: 7212 Earthquake ground motions and engineering
DE: 7223 Seismic hazard assessment and prediction
DE: 7260 Theory and modeling
SC: Seismology [S]
MN: 2003 Fall Meeting