Comparison of Site Dominant Frequency from Earthquake and Microseismic Data in California

摘要

An important predictive variable for site amplification is the site dominant frequency (f(d)). At seismic monitoring stations, f(d) can be calculated from the peak of the horizontal-to-vertical spectral ratios (HVSRs) obtained from earthquake recordings (eHVSR). For other sites, f(d) can be estimated from microseismic (mHVSR) observations. We compare the f(d) values derived from eHVSR (5% damped response spectra from the Next Generation Attenuation-West2 [NGA-West2] database; Ancheta et al., 2014) with those derived from mHVSR (Fourier spectra from Yong et al., 2013) for seismic stations in California. We show that the logarithm of eHVSR f(d) scales linearly with the logarithm of mHVSR f(d), with a standard deviation of 0.14 log10 units for mHVSR f(d) larger than 0.2 Hz. The relationship holds for microseismic surveys at distances up to 300 m away from the seismic stations. The results of this study have beneficial implications for the characterization of site response in modern ground-motion models as well as in building codes.