08-10-2014, 04:23 PM
A probabilistic seismic hazard analysis has been carried out for the North-East India. Probabilistic seismic hazard maps have been prepared based on the uniform hazard response spectra for absolute acceleration at stiff rock/rock sites, as those represent a much more complete characterization of seismic hazard than the traditional maps prepared on the basis of peak ground acceleration. For doing the hazard analysis, a new attenuation model based on pseudo-spectral velocity scaling has been proposed by using 261 recorded accelerograms. The entire North-East India has been divided into 0.1̼̉ grid size, and the hazard level has been assessed for each node of this grid by considering the seismicity within a 300 km radius area around the node. Using the past earthquake data, the seismicity for the area around each node has been evaluated by defining a and b values of the Gutenberg-Richter recurrence relationship, while taking care of the completeness of the earthquake catalogue. Each node has been considered to be disturbed by 50 annular source elements, for each of wh