Abstract
During the time interval of 3 February to 20 April 1988 four independent main shocks occurred in North-East (NE) India: 03/02/1988, M = 5.5; 06/20/1988, M = 5.8; 15/04/1988, M = 6.2 and 20/04/1988, M = 5.8. The seismicity rate within this 78 day interval is increased by a factor of 15 and 6 with respect to the mean, long term seismicity for M ≥ 5.5 and M ≥ 6.1, respectively. In terms of probability, it has been found out that the probability of observing by chance four events of M ≥ 5.5 or one events of M ≥ 6.1 in NE-India is equal to only 0.4243 and 0.3680, respectively. These results imply that the observed seismicity has a non-random time clustering. Similar earthquake time clusters were identified to have occurred in NE-India in 1930 and 1951. A triggering mechanism has been proposed to interpret the earthquake clustering: the first event of the earthquake sequence produces transient stress changes that cause an acceleration to the static stress loading, and then to seismic failure, to remote highly pre stressed regions.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
