Site Classification of Strong Motion Stations of Uttarakhand, India, Based on Standard Spectral Ratio, and Horizontal-to-Vertical Spectral Ratio Methods

Program for excellence in strong motion studies) (PESMOS) is an important accelerogram database in India consisting of earthquake records from 300 recording stations (RSs) located across the country. A major limitation of PESMOS database is the lack of accurate information on the seismic site class of RSs, which is essential for the utilization of ground motion records in seismic hazard and ground response studies. In the absence of in-situ field study data, site class of RSs can be determined indirectly analyzing recorded ground motions using empirical and semiempirical methods. In the present study, site class for 4 RSs located in the eastern region of Uttarakhand is established in accordance with the predominant frequency values obtained using standard spectral ratio method (SR), generalized inversion technique (GINV) as well as horizontal-to-vertical spectral ratio method (HVSR).