SITE EFFECTS IN AN ALLUVIAL VALLEY: A COMPARISON OF ESTIMATES FROM EARTHQUAKE AND MICROTREMOR RECORDS

摘要

We present results of the comparison between site effect estimates using different types of data: earthquake and microtremor records. Site effects from earthquake records were analysed using three different techniques that represent the state-of-practice. Microtremor records were analysed using the HVSR technique (horizontal to vertical component spectral ratios). We observed the usual similarities between both sets of results. In a second time, we have investigated the reasons for those similarities. To this end we analysed the nature of wave propagation in microtremor recordings using f-k spectra. Our results suggest a possible explanation of the similarities between estimates of site effects obtained using earthquake records and those obtained using microtremor records.