HVSR recording duration for regolith sites: an experimental approach

Abstract

The application of the horizontal vertical spectral ratio (HVSR) technique using microtremor measurement to quantify the natural period of sites in urban areas is widely used around the world. However, this technique is still under development in regions with low impedance contrast between the top layer and the underlying bedrock, such as regolith. This paper investigates the recording duration of the aforementioned method for quantifying the site fundamental frequency in regolith environments. An experimental study has been carried out at a regolith site where two days of continuous data acquisition are used to investigate the HVSR technique measurement duration. A series of reliability tests were applied to the HVSR analysis results. The analyses suggest that at least 20 minutes duration is required for more reliable HVSR analysis results at regolith sites.