VS30 at Three Strong-Motion Recording Stations in Napa and Solano Counties, California--Lovall Valley Road, Broadway Street and Sereno Drive in Vallejo, and Vallejo Fire Station--Calculations Determined From S-Wave Refraction Tomography and Multichannel Analysis of Surface Waves (Rayleigh and Love) [open pdf - 17MB]
From the Introduction: "In May 2015, we acquired high-resolution seismic profiles near three strong-motion recording stations in Napa and Solano Counties, California (fig. 1; stations 4 to 6). These three strong-motion stations recorded horizontal peak ground accelerations (PGAs) ranging from 0.329 g (the acceleration due to gravity at the Earth's surface) to 0.469 g (table 1), among the highest recorded in the Napa and Vallejo areas during the August 24, 2014, moment magnitude (Mw) 6.0 South Napa earthquake. Our goal was to evaluate the seismic velocities of the underlying geologic materials at the strong-motion sites using P- and S-wave refraction tomography and analysis of surface waves and to evaluate time-averaged shear-wave velocities (VS) in the upper 30 meters (m) of the subsurface (VS30) at the sites using methods similar to those used by Catchings and others (2018). In this report, we present results from the three sites--Lovall Valley Loop Road in Napa County (NCSN N019B), Broadway Street and Sereno Drive in Vallejo (CGS 68294), and Vallejo Fire Station on Marin Street and Overland Alley (NSMP 1759)."
Open-File Report 2018-1162
United States Geological Survey: http://www.usgs.gov/