SEISMICITY OF NORTH WESTERN HIMALAYA

Abstract

The Himalayan region is one of the most seismically active regions of the world; it is part of the Alpine Himalayan seismic belt and is in a continent-continent collision zone. Strain energy is progressively accumulating in the Himalayas due to continued collision of the Indian plate with the Eurasian plate, and this energy gets released from time to time in the form of several destructive earthquakes. The amount of loss in terms of life, property and disruption of key infrastructure has been rising continuously after every earthquake. An attempt is made to compile seismicity and tectonic data of North Western Himalaya, mostly from Seismotectonic Atlas of India and its Environs (2000), for an area between longitudes 73° - 84° E; and latitudes 25° - 36°N, for the period of 1833-1998. This large region includes the Great Kangra earthquake of 1905 in the west and the Great Bihar Nepal earthquake of 1934 in the east. It also includes 18 digitized isoseismal maps; fault plane solution of 19 thrust type, 14 strike slip and 4 normal events; and description of 19 destructive earthquakes. In addition 53 named tectonic units in the form of faults, thrusts, grabens, lineaments, fold belts, subsurface ridges, basins, syntaxes and basins are also included. This data, with more inputs, will - prove useful for managing and mitigating seismic hazards.