Probabilistic seismic hazard for Himalayan region using kernel estimation method (zone-free method)

Abstract

In view of active seismic status of the Himalayan belt and continued developmental activities in mountainous states, it is imperative to update knowledge of seismic hazard incorporating latest knowledge on earthquake occurrence and attenuation process. The present research work delivers new-generation probabilistic seismic hazard information for northwest and central Himalayan region. We adopted a noble approach following a zone-free method, first time, for the Himalayan region to estimate the ground motion at bedrock level, the results of which are compared with the contemporary zoning method for the same area. Employing new-generation ground motion prediction equations, peak ground acceleration and spectral acceleration have been estimated in the region for return periods of 475, 975 and 2475 years (10, 5 and 2% exceedance in 50 years, respectively). The zone-free method predicted maximum ground motions in two areas Kashmir valley and eastern part of the Uttarakhand and the westernmost part of the Nepal. The ground motion ranges from 0.04 to 0.60 g for 2475-year return period.