UCLA

Frequency-dependent horizontal-to-vertical spectral ratios (HVSR) can provide information on site resonant frequencies, which are potentially useful for predicting site amplification. We adapt a relational database developed to archive and disseminate VS data to include HVSR and investigate the consistency of HVSR derived from different measurements of ambient noise (temporary instruments, permanent instruments) and earthquake recordings. The database as a whole consists of 2,797 sites in California. HVSR consistency is analyzed using subsets of sites with multiple data sources; noise and seismic data are consistent for 60% of sites, whereas different noise measurements have about 75% consistency.