Seismic source modeling and probabilistic seismic hazard analysis for Bangladesh

Abstract

The probabilistic seismic hazard analysis (PSHA) has been performed for Bangladesh using background seismicity, crustal fault, and subduction zone source models. The latest ground motion prediction equations (GMPEs) that are developed using global data sets have been used to estimate ground motion. The uncertainties in seismic sources and GMPEs to estimate ground motion are accounted using the logic tree approach. The activity rates of the background and regional seismicity sources are estimated using a declustered and complete catalog of the study regions. The activity rates of the crustal fault and subduction zone sources are estimated from the geodetic strain rates using the well-accepted relationships. The peak ground acceleration (PGA) and spectral acceleration (SA) at spectral periods of 0.2, 0.5, 1.0, 2.0, 5.0, and 10.0 s have been estimated at a grid size of 0.250 at the bedrock ground condition. The PGA and SA maps of various spectral periods have been prepared for Bangladesh for both 10% and 2% probability of exceedance in 50 years. These seismic hazard maps can be used for seismic risk management of Bangladesh.