HR: 1330h
AN: S32A-0838    [PDF]
TI: Receiver Function Imaging of the Crustal and Uppermost Mantle Structure Beneath Southern California
AU: * Yan, Z
EM: yanmei@gps.caltech.edu
AF: California Institute of Technology, MC252-21, CALTECH, PASADENA, CA 91125 United States
AU: Clayton, R W
EM: clay@gps.caltech.edu
AF: California Institute of Technology, MC252-21, CALTECH, PASADENA, CA 91125 United States
AB: We analyzed receiver functions for 30 large events recorded on the high-sample rate channels (100 sps) of TriNet stations in the Transverse Ranges and Mojave Desert, California. Stations in Mojave Desert show a clear Moho interface around 3.8 sec (30 km depth). For stations in a line across the San Gabriel Mountains we found: (1) A mid crustal interface exists around 20-25 km. A bright spot right above this interface is imaged under Mt. Wilson, which is close to the location of the bright spot imaged from seismic reflection surveys by Fuis et al. (Geology, 2001). (2) From south to north, the Moho has a classic mountain root shape with the deepest point at 40 km at a horizontal point approximately 10 km to the south-west of the San Andreas Fault. The root is shifted to the NW relative to the topography. (3) A continuous deep shallow-dipping interface is imaged beneath the San Gabriel Mountains at depths around 80-90 km. The layer dips down to the NW. Its location indicates this layer is probably related to the subducted Farallon slab. Deep Moho is also imaged for stations in San-Bernardino Mountains, and at the junction of the Garlock and San Andreas Faults (i.e., both ends of the 'Big Bend').
DE: 7218 Lithosphere and upper mantle
DE: 9350 North America
SC: Seismology [S]
MN: 2003 Fall Meeting