Site Response Analyses of U.S. Geological Survey Seismic Stations Deployed After the M6.4 and M7.1 Ridgecrest Earthquakes

Session: Near-Surface Effects: Advances in Site Response Estimation and Its Applications
Type: Oral
Date: 4/28/2020
Time: 11:45 AM
Room: 110 + 140
Description: 

We report on observations of seismic site response using data from the aftershock sequence recorded by nine temporary U.S. Geological Survey Rapid Aftershock Pasadena (RAP) stations deployed following the M6.4 and M7.1 Ridgecrest earthquakes. Six stations were sited in the active aftershock zone located on the Naval Air Weapons Station-China Lake and three were sited just south of the base boundary on U.S. Bureau of Land Management lands. We apply the horizontal-to-vertical-spectral-ratio (eHVSR) analysis technique on the earthquake aftershock data to estimate the fundamental (f0) and dominant (fd) site frequencies at each RAP recording site. mHVSR analyses using microseismic (ambient) noise data recorded between the earthquakes are also performed when data are available. Next, we apply the standard spectral ratio (SSR) technique to analyze earthquake data recorded from the nine RAP sites against data from nearby surrounding permanent network recording stations that are sited on hard rock conditions. We report on our comparisons of results derived from eHVSR, mHVSR and SSR. We discuss the variations in f0 and fd as estimated from each technique and the uncertainty associated with each method.

Presenting Author: Kenneth S. Hudson

Authors