Estimation of site amplification at various litho-units in NW-Himalaya using horizontal to vertical ratio

Abstract

This note is a result of an off-shoot study carried out of a reconnaissance seismic noise survey to establish broadband seismological stations. The survey was conducted in Kumaun Himalaya for the purpose of characterizing background seismic noise characteristics. This paper deals with the estimation of local site effects at various locations with varying geological and tectonic environments in the region. The effects of the various litho units on the site's predominant frequency are depicted here. It is seen that the character of the top sedimentary column and its compaction plays a vital role in the estimation of site response. The level of tectonic complexity is also reflected in the noise spectra of the studied regions. The region in close proximity of the MCT zone exhibits high background seismic noise level. © Geol. Soc. India.