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A new region-specific Ground Motion Prediction Equation (GMPE) was developed for the North and Central Himalayas purely based on recorded strong motion data. The GMPE was generated using multiple-regression, considering ground acceleration, magnitude, and hypocentral distance. An updated larger dataset was used in the present study, making the new equation applicable to a larger magnitude range of 4.1 to 7.8 and distance range up to 1560 kms, thus overcoming a major limitation of currently available region-specific GMPEs. The new GMPE was validated and observed to predict ground acceleration more accurately with noticeably less residuals as compared to existing GMPEs. [ABSTRACT FROM AUTHOR]

Recently developed region-specific GMPEs are used for a comprehensive seismic hazard analysis (SHA) of the North and Central Himalayas (NCH) using a probabilistic approach considering two source models. Vulnerable seismic sources in the areas are identified based on the Seismotectonic Atlas (Dasgupta et al. 2000), published by the Geological Survey of India. An up to date, homogenized and declustered earthquake catalogue is compiled from various sources, with earthquake data since 250 BC, to create a new digitized seismotectonic representation of the region. Regional seismic zones having similar seismicity are recognized based on the Gutenberg-Richter (GR) parameters and the region is delineated into 5 seismic zones. The study area is divided into grids of size 0.05° × 0.05° and the hazard in terms of Peak Ground Acceleration (PGA) at the centre of each grid point is estimated and presented as hazard maps for individual seismic sources, maximum of all sources, and average of both sources. From the current study, it could be concluded that the PGA estimated in the regions is comparatively higher than what is reported in the codal provisions for seismic zonation and estimation of design horizontal acceleration for the region. [ABSTRACT FROM AUTHOR]