HR: 0800h
AN: S31A-0276    [Abstracts]
TI: California Surface Wave Tomography from Ambient Seismic Noise: Tracking the Progress of the USArray Transportable Network
AU: * Moschetti, M P
EM: morganm@ciei.colorado.edu
AF: Center for Imaging of the Earth's Interior, Department of Physics,University of Colorado at Boulder, Campus Box 390, Boulder, CO 80309-0390
AU: Ritzwoller, M H
EM: ritzwoll@merckx.colorado.edu
AF: Center for Imaging of the Earth's Interior, Department of Physics,University of Colorado at Boulder, Campus Box 390, Boulder, CO 80309-0390
AU: Shapiro, N M
EM: nshapiro@ciei.colorado.edu
AF: Center for Imaging of the Earth's Interior, Department of Physics,University of Colorado at Boulder, Campus Box 390, Boulder, CO 80309-0390
AB: We have extended the application of high resolution ambient noise surface wave tomography across all of California by incorporating emerging data from the USArray Transportable Array (TA) component of Earthscope. Ambient seismic noise contains a significant component of Rayleigh wave energy from which the Green function between pairs of stations can be extracted by cross-correlating long noise sequences. Surface wave group velocities are then measured on the estimated Green functions. Early efforts were applied to records from USArray TA stations in Southern California and resulted in the construction of high-resolution short-period (7-18 s) surface wave dispersion maps and the imaging of the principal crustal geological units in Southern California (Shapiro et al., Science, 307, 1615, 2005). As the spatial coverage of the USArray TA in Northern California has improved over the past year, the number of potential receiver pairs and their resulting sampled paths have increased proportionately. We have extended surface wave tomography across California by computing cross-correlations to obtain short period (7-25 s) surface wave group velocity measurements for paths across the state. The majority of the paths in Northern California result from the recent emplacement of USArray TA instruments. Cross-correlations of three month time windows, starting in October 2004 and continuing through September 2005, result in evolving maps of the surface wave group velocities in Northern California. Newly imaged tomographic features are seen to emerge as the resolution improves.
DE: 7255 Surface waves and free oscillations
DE: 7270 Tomography (6982, 8180)
SC: Seismology [S]
MN: Fall Meeting 2005