Attenuation relations for strong seismic ground motion in the Himalayan region

Strong motion data from various regions of India have been used to study attenuation characteristics of horizontal peak acceleration and velocity. The strong ground motion data base considered in the present work consists of various earthquakes recorded in the northern part of India since 1986 with magnitudes 5.7 to 7.2. Using these data, relations for horizontal peak acceleration and velocity, which are log(10)a = 1.14 +/- 0.31M + 0.65 log(10) R log(10) v = 0.571 + 0.41M + 0.768 log(10) R have been proposed where a is the peak horizontal acceleration in cm/sec(2), v is the peak horizontal velocity in mm/sec, M is body wave magnitude, and R is the hypocentral distance in km. The proposed relations are in reasonable agreement with the small amount of strong ground motion data available for the northern part of India. The present results will be useful in estimating strong ground motion parameters and in the earthquake resistant design in the Himalayan region.