Within-site variability in earthquake site response

SUMMARY The within-site variability in site response is the randomness at a given from different earthquakes and treated as aleatory current seismic hazard/risk analyses. In this study, we investigate single-station linear K-NET KiK-net stations Japan using large number of earthquake recordings. We found that standard deviation horizontal-to-vertical Fourier spectral ratio individual sites, (HVSR) sigma σHV,s, approximates quantified surface-to-borehole ratios (for oscillator frequencies higher than fundamental frequency) or empirical ground-motion models. Based on finding, then utilize HVSR convenient tool to study site-response 697 1169 sites. Our results show certain frequencies, stiff, rough shallow well small local events tend have σHV,s. However, when being averaged over sigma, σHV, increases gradually with decreasing frequency. frequency range 0.25–25 Hz, σHV centred 0.23–0.43 ln scales (a scale factor 1.26–1.54) one less 0.1. quite stable across tectonic regions, present constant, magnitude- distance-dependent