HR: 10:40h
AN: S32A-02 INVITED     [Abstracts]
TI: Extraction of Green Functions From Correlations of Seismic Noise
AU: * Fehler, M
EM: fehler@lanl.gov
AF: Geophysics Group; Los Alamos National Laboratory, Ms D443, Los Alamos, NM 87545 United States
AU: Gerstoft, P
EM: gerstoft@ucsd.edu
AF: Marine Physical Laboratory, University of California San Diego, La Jolla, CA 92093 United States
AU: Sabra, K
EM: ksabra@mpl.ucsd.edu
AF: Marine Physical Laboratory, University of California San Diego, La Jolla, CA 92093 United States
AU: Roux, P
EM: proux@ucsd.edu
AF: Marine Physical Laboratory, University of California San Diego, La Jolla, CA 92093 United States
AU: Kuperman, W
EM: wak@mpl.ucsd.edu
AF: Marine Physical Laboratory, University of California San Diego, La Jolla, CA 92093 United States
AB: An estimate of the point-to-point seismic propagation Green functions can be extracted from seismic noise by cross correlation of records at nearby stations. The resulting Green is band-limited to the band of the correlated seismic noise. To date, several investigators, including us, have successfully shown that short-period surface waves can be obtained using data recorded by regional seismic networks. Others have shown that longer-period surface wave Green Functions can be obtained from more widely-spaced stations. We have recently shown that portions of the body wave Green functions can be obtained from noise correlation. The traveltimes of short-period surface waves recorded between a large number of station pairs for stations within a seismic network can be inverted to determine a tomographic map of Group Velocities. The resulting tomographic maps have been found to compare well with group velocities inferred from independent studies of shallow structure. For data analyzed from California, the amplitude of the Green Function between pairs of stations varies with the orientation of the line connecting stations relative to the orientation of the coast line. By normalizing the resulting Green Function by the amplitude of the noise recorded at the two stations, we may obtain information about the relative attenuation along the path between the stations.
DE: 1219 Gravity anomalies and Earth structure (0920, 7205, 7240)
DE: 7203 Body waves
SC: Seismology [S]
MN: Fall Meeting 2005