The Seismicity Of North East India- Its Strain Release, Accumulation And Potentiality And Seismic Indifference In The Assam Gap: An Analysis

Document Type : Primary Research paper


Assistant Professor, Dept of Geography Tinsukia College, Tinsukia, Assam. India


North-East India (N.E. India) is highly earthquake vulnerable area surrounded by the Himalayas, Arakan Yoma, Hills and plains of Bangladesh, etc. it falls within the zone V of seismic intensity and one of the sixth active zones of the world. Its earthquakes are all of morphometric mainly due to collision between India and Chinese plates in the north and Indian and Burmese plates in the east and south and due to local rift and fault displacements that criss-cross the whole region. The region has the highest strain release in 1897 and 1950 based on which it may be observed that the strain is somehow gaining accumulation here day by day and increase the seismic potentiality of a great earthquake to be occurred in near future. Again from isostrain map, it is to be noticed that the valley part of the Brahmaputra & Barak and the Shillong Plateau have the high accumulation strain and low release of strain. Assam Gap zone named by Kayal as Aseismic Corridor has the lowest release of strain or almost nil is becoming a mysterious zone for the seismologists and apprehension of presence of future strong epicenter in this zone is increasing.But two zone shows no reaction to the morphotectonics of the region except few in the long history and the sign of future presence of epicenter in this zone is still remain uncertain as per theory and applied seismological sciences. North-East India may be divided into six seismotectonic zones as Eastern Himalayan Collision Zone, Indo-Myanmar Subduction Zone, Syntaxial Zone of Himalayan Arc and Burmese Arc (Mishimi Hills), Plate boundary Zone of Tripura-Mizoram Fold belt and the Aseismic Corridor or Asaam Gap Zone.