Seismic recording in eastern California of the KEARSARGE nuclear test

A temporary ten-station seismic network was operated in eastern California to record the KEARSARGE nuclear test at the Nevada Test Site. Data from 8 three-component, short-period stations and 2 three-component, mid-period stations are presented. Part of the array was arranged as a profile between 150 to 250 km from NTS. At these ranges, the first arrivals are Pn waves refracted along the crust-mantle boundary. The Pn travel times can be modeled by assuming a 32-km thick crust at NTS, which as a 3° westward dip beginning approximately 90 km west of the shot point. This model predicts a crustal thickness of 41.8 km at a point 277 km west of the shot point (that is, under the central Sierra Nevada). This model is in good agreement with the models of Eaton and of Pakiser and Brune and contrary to the model of Carder et al and Carder. There still remain significant offsets in the Carder et al NTS travel-time data in the 250 to 270 km and 360 to 390 km distance ranges. Closely-spaced, digitally-recorded observations in those distance ranges are needed to completely resolve the seismic structure of the Sierra Nevada-Basin and Range transition zone.