HR: 0800h
AN: S11A-0280    [Abstracts]
TI: Testing Community Velocity Models of Southern California Using Ambient Seismic Noise
AU: * Ma, S
EM: shuoma@stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305, United States
AU: Prieto, G A
EM: gprieto@stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305, United States
AU: Beroza, G C
EM: beroza@pangea.stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305, United States
AB: Correlation of ambient seismic noise has been shown both experimentally and theoretically to reveal robust and accurate Green's function between station pairs. Such data have led to the emerging field of ambient noise tomography. In this study, we correlate monthly data recorded on about 100 broadband seismic stations in Southern California with dense coverage in the Los Angeles area, to determine a large number of station-to-station Green's functions that are dominated by surface waves in the frequency band we are using. These data provide strong constraints on the shallow velocity structure of Southern California in areas of particular interest for seismic hazard analysis. We compare Green's functions from noise correlation (up to 1 Hz) with Green's functions calculated with a versatile finite-element method in the current community velocity models for Southern California (SCEC CVM 4.0 and SCEC CVM-H 4.0). The comparisons provide a comprehensive test of community velocity models for Southern California. The results show the potential for using these methods to target areas of poorly known velocity structure or for ray paths not constrained by regional seismicity. This is particularly relevant for extended faults, like the San Andreas, which are of high concern, but exhibit little to no background seismicity. Deploying seismic stations along the fault would allow the Green's function to the LA Basin to be recovered, and be used for accurate modeling of wave propagation from dynamic rupture models.
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7255 Surface waves and free oscillations
DE: 7290 Computational seismology
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: 2007 Fall Meeting