Study of the Great Assam Earthquake of August 1950 and its aftershocks

Epicentre  and  origin time  of  the  Great  Assam earthquake of 15 August 1950 and  54 other earthquakes shocks which occurred in the Assam region upto the end of Apri11951 have been determined by the Least Square method. Magnitudes of these shocks have also been estimated from data of Indian stations. Using data of near stations at Tocklai, Tezpore, Shillong (specially opened for  this study) and of Calcutta and Chatra, the velocities of seismic  waves  in Assam  have  been calculated  within  narrow 1imits of error and estimates of depth of crustal lyers.have  been obtained. Travel  times of seismic waves in Assam and neigbourhood have been compared with the travel time tables of Jeffreys and Bullen (1940).