Prediction of Strong Ground Motion at Somnath Temple

Abstract Seismic hazard assessment is the key tool for rational planning and designing in seismically vulnerable regions. Gujarat state of India is the only state in peninsular India with maximum seismic hazard of big shallow earthquake originating from Intraplate seismicity. Entire Gujarat region has earthquake hazard of different levels from moderate to high as seismic zones III to V are assigned as per the seismic zoning map of India [IS:1893 Part 1 (2002)]. In the present study, seismic hazard assessment for Gujarat state of India is performed by using state of art probabilistic seismic hazard assessment procedures for selected areas. Using on seismotectonic information a possible fault map is prepared and using calculated regional seismicity parameter, earthquake recurrence relationships are established for each fault. Probabilistic seismic hazard assessment in terms of horizontal component of peak ground acceleration for 5% structural damping for the rock sites are carried out using seven different ground motion prediction equations (GMPEs) including one from India. The output of the seismic hazard computations are then used to develop uniform hazard spectra (UHS) for the two earthquake return periods (i.e.475-years and 2475-years).