Site Response in Las Vegas Valley, Nevada from NTS Explosions and Earthquake Data

摘要: We report site response in Las Vegas Valley (LVV) from historical recordings of Nevada Test Site (NTS) nuclear explosions and earthquake permanent temporary seismic stations. Our data set significantly improves the spatial coverage LVV over previous studies, especially northern, deeper parts basin. at stations was measured for frequencies range 0.2–5.0 Hz using Standard Spectral Ratios (SSR) Horizontal-Vertical (HVR). For SSR measurements we used a reference (approximately NEHRP B ``rock'' classification) located on Frenchman Mountain outside sedimentary sites is variable with average amplifications approaching factor 10 some frequencies. observed peaks curves clustered near 0.6, 1.2 2.0 Hz, showing additional lower amplitude higher The pattern strongly correlated reported depth to basement between 0.2 3.0 although frequency peak amplification does not show similar correlation. few where have geotechnical shear velocities, shows correlation upper 30-meter V 30. performed two-dimensional finite difference simulations reproduced 0.6 low velocity near-surface layer velocities 600–750 m/s thickness 100–200 m. These modeling results indicate that are controlled by shallow structure.