Measurements and Predictions of Vs30, Z1.0, and Z2.5 in Nevada

The Nevada Seismological Laboratory has posted a public database of Refraction Microtremor (ReMi) survey results of shear-wave velocity (Vs) versus depth in the Reno-area basin, and additional locations. Most of the Vs profiles were published previously in peer-reviewed journal articles. The database collects values of Vs30, Z1.0, and Z2.5 measured at 170 sites throughout the basin. Vs30 is the time-averaged Vs between the surface and 30 m depth. Z1.0 is the depth to the first occurrence of Vs = 1.0 km/s or greater, and Z2.5 is the depth to Vs = 2.5 km/s. The database contains many more Reno-area sites with Vs30 measurements that did not also have a Z1.0 measurement; this report does not examine sites without Z1.0 values. All but a few sites have Vs30 between 260 m/s and 760 m/s, with a majority in NEHRP hazard class C. Sites that are geologically on bedrock have unexpectedly low Vs30, 0.1 km, and some basin sites have Z1.0