HR: 15:10h
AN: S43C-07    [Abstracts]
TI: Azimuthal Anisotropy and Travel Path Complexities from Particle Motions: Southern California Array Analysis
AU: * Prindle, K L
EM: kenton_prindle@umail.ucsb.edu
AF: University of California, Santa Barbara, 552 University Road - Bldg 526, Santa Barbara, CA 93106-9630 United States
AU: * Prindle, K L
EM: kenton_prindle@umail.ucsb.edu
AF: Institute of Crustal Studies, 1140 Girvetz Hall UC Santa Barbara, Santa Barbara, CA 93106-1100 United States
AU: Tanimoto, T
EM: toshiro_geol.ucsb.edu
AF: University of California, Santa Barbara, 552 University Road - Bldg 526, Santa Barbara, CA 93106-9630 United States
AU: Tanimoto, T
EM: toshiro_geol.ucsb.edu
AF: Institute of Crustal Studies, 1140 Girvetz Hall UC Santa Barbara, Santa Barbara, CA 93106-1100 United States
AB: We recover azimuthal anisotropy for well resolved regions in Southern California using Rayleigh wave data obtained from the California Integrated Seismic Network. Initial results show strong anisotropy in Southern California, particularly near the Transverse Ranges, with orientation of the fast-axis being approximately margin parallel. Comparison of heterogeneous phase velocity maps including anisotropy and those not including anisotropy illustrate the necessity of anisotropy in the phase velocity inversions due to significant change in phase velocity distributions in the region. Resolution tests have been carried out for anisotropy, illustrating that only long wavelength features (1.0 - 1.5 Degrees) can be reasonably recovered. There are large contributions due to azimuthal anisotropy seen in amplitude of S-wave velocity perturbations, but overall velocity features remain intact from our previous inversions. The strongest anisotropy anomaly occurs near the Transverse Ranges, where a postulated fast velocity root existed in our original S-wave velocity inversion. Particle motions were analyzed in order to ensure our great-circle path assumption was adequate to explain the travel path between two stations. Initial results show that for most incoming travel path directions our assumption is valid, but for certain azimuths, particle motions deviate considerably from expected values, most likely due to refractions off of local or travel path structures. More work is necessary in order to examine these deviations in more detail.
DE: 7218 Lithosphere (1236)
DE: 7250 Transform faults
DE: 7255 Surface waves and free oscillations
DE: 7270 Tomography (6982, 8180)
DE: 7294 Seismic instruments and networks (0935, 3025)
SC: Seismology [S]
MN: Fall Meeting 2005