HR: 0800h
AN: S41B-0563    [Abstracts]
TI: Rayleigh and Love wave tomography of the western United States from ambient seismic noise using USArray
AU: Lin, F
EM: linf@colorado.edu
AF: Center for Imaging the Earth's Interior, Department of Physics, University of Colorado at Boulder, Boulder, CO 80309, United States
AU: * Moschetti, M P
EM: morganm@anquetil.colorado.edu
AF: Center for Imaging the Earth's Interior, Department of Physics, University of Colorado at Boulder, Boulder, CO 80309, United States
AU: Ritzwoller, M H
EM: ritzwoll@anquetil.colorado.edu
AF: Center for Imaging the Earth's Interior, Department of Physics, University of Colorado at Boulder, Boulder, CO 80309, United States
AB: We present the most recent results of Rayleigh wave and Love wave tomography in the western United States using ambient seismic noise observed at 424 broadband stations from the EarthScope/USArray Transportable Array and regional networks. All available three-component time series between 1 October 2005 and 31 Aug 2007 have been cross-correlated to yield estimated empirical Rayleigh and Love wave Green¡¦s functions. Phase and group velocity dispersion curves for both Rayleigh and Love waves between 5 and 40 sec period are measured for each inter-station path by applying frequency-time analysis and are then used to invert for Rayleigh and Love wave speed maps. The significant velocity variations observed on the short period maps suggest that it may not be appropriate to use straight ray theory in these inversions. To investigate both the off-great-circle and finite- frequency effects, we apply a 2D finite difference wave propagation simulation combined with the adjoint method. We investigate the effects on ray geometry, travel time measurement, and tomography.
DE: 7205 Continental crust (1219)
DE: 7255 Surface waves and free oscillations
DE: 7270 Tomography (6982, 8180)
DE: 7290 Computational seismology
SC: Seismology [S]
MN: 2007 Fall Meeting