Site amplification effects based on teleseismic wave analysis: the case of Pellice Valley (Piedmont, Italy)

Abstract

The investigation of local amplification phenomena by seismic signal analysis is a fundamental step in carefully defining the seismic response of an area. In this study we investigate the use of teleseismic recordings in assessing seismic wave amplification in the Pellice Valley (North-western Alps, Italy). Assuming that teleseismic P-waves are sensitive to the deep structure of a basin, we deal with the computation of horizontal to vertical spectral ratios and with the estimate of teleseismic P-wave arrival time delays and P-wave amplifications with respect to a reference site. The reliability of the H/V results obtained by considering teleseismic signals is confirmed by the agreement with the results coming from both H/V of noise and H/V of S-wave of local events methods. Strong correlation between the P-wave arrival time delays and the relative P-wave amplifications with respect to thickness of the low velocity layers and the geometry of the bedrock is found.