ABSTRACT
If not from antiquity, as the record reveals, since historical times North Eastern Region of India has obviously been continuing as a mute spectator to a series of devastating earthquakes, and not to speak of the later ones. The historical records of Ahom Kingdom alone would be sufficient to place the region as one among the severe-most seismic zones of the World. However, based on other seismic records of early colonial period and the era of post instrumental recording including those of two great ones – widely known as the Shillong Earthquake of 12 June 1897 and the Assam earthquake of 15 August 1950, both measuring 8.5 on the Richter Scale – a more or less well accepted plate tectonic model has also been worked out by now for the region. As the general understanding goes – tectonically north-east India is located in between the two sets of active plate boundaries also forming a part of the great Alpine Himalayan Seismic belt. North of this region is wholly bounded by the Himalayas, i.e. the junction of Indo-Eurasian plates and in the east down south-east, the region is surrounded by another plate junction popularly known as Indo-Myanmar plate junction and towards both east-south east and north direction Indian plate is going below the neighbouring plates. In between the plate junctions, the part of Indian plate with its raised Shillong plateau and the tectonically guided mighty Brahmaputra is virtually compressed to a high degree from both the sides and appears to be pushed more from the south east direction there by making the region a super seismic area already recording a number of seismic events of all categories from micro to the great ones.
