Probabilistic Seismic Hazard Analysis of Punasa Dam Site in India

Probabilistic Seismic Hazard Analysis (PSHA) is the evaluation of annual frequencies of exceedance of ground motion levels. Probabilistic seismic hazard for the site specific Punasa dam has been estimated. Punasa dam is located in the Khandwa district on the life line river Narmada of Madhya Pradesh state of India. The PSHA of the Punasa dam site has been estimated considering the seismically active faults out of the total faults available in the area. Effects of all the faults, which can produce earthquake equal to or more than 3.5 magnitudes has been considered. The fault considered in the present work consists of 35 active faults out of total 126 faults, for which a minimum amount of information was available (i.e. length, maximum magnitude, etc.). For this purpose, an area of radius 500–550 km is selected. There are 154 earthquakes (moment magnitude 3.5–6.6) occurred in this region during last 210 years from 1808 to 2017. Completeness of this data is checked by Stepp’s method. For this data Gutenberg-Richter (G-R) parameters (a and b values) are estimated by regression analysis. Results are presented in a form of Peak Ground Acceleration (PGA) and seismic hazard curves.