HR: 0800h
AN: S51B-1007    [Abstracts]
TI: 3-D Velocity Models and Earthquake Locations in Southern California With Synthetic Data Tests
AU: * Lin, G
EM: gulin@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Dr, La Jolla, CA 92093 United States
AU: Shearer, P M
EM: pshearer@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Dr, La Jolla, CA 92093 United States
AB: We present earthquake relocations in southern California obtained from 3-D velocity inversion and waveform cross-correlation times. We select about 3000 distributed master events within 7 by 7 by 4 km cells and pick the S-waves for these events manually. We then implement the Thurber algorithm (e.g., Evans et al., 1994, USGS-OFR-94-431) to obtain 3-D crustal velocity structure and hypocenter locations for the master events. We use synthetic data and controlled sources in order to estimate the resolving power of our data set and the reliability of the model. Using the resulting 3-D model and a source-specific station term (SSST) approach we relocate all seismicity in southern California from 1984 to 2002. We perform cluster analysis to identify similar event clusters using the waveform cross-correlation results and then relocate each similar event cluster using the cross-correlation times with a robust least squares approach. These results build on the relocated catalogs of Hauksson and Shearer (2005) and Shearer et al. (2005) and provide additional insight regarding the fine-scale seismicity structure in southern California. A long-term goal is to expand these methods to produce a unified 3-D velocity model and earthquake catalog for California, combining both northern and southern California network data.
DE: 7270 Tomography (6982, 8180)
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: Fall Meeting 2005