Teleseismic surface wave tomography in the western U.S. using the Transportable Array component of USArray

Abstract

Fundamental mode Rayleigh waves recorded by the Transportable Array component of EarthScope/USArray from January 2006 through April 2007 are used to generate phase velocity maps at periods from 25 to 100 sec across the western U.S., including Washington, Oregon, California, Nevada and western Idaho. At short periods (25–33 s), low velocity anomalies are observed in western Washington, western and central Oregon, northern California, the southern Sierra Nevada and the Snake River Plain. At intermediate and long periods (50–100 s), high velocities are seen in the Cascades, the southern Central Valley of California, California's Transverse Range, and the Columbia River Flood Basalt Province. The phase velocity maps are consistent with those obtained from ambient noise tomography at comparable periods. Short period phase velocities from ambient noise tomography and the longer‐period phase velocities from teleseismic tomography, therefore, present natural data sets to invert jointly 3‐D structure across the western U.S.