RESERVOIR-TRIGGERED SEISMICITY: RELEVANCE TO NORTH EAST INDIA

Abstract

The often neglected issue of reservoir-triggered seismicity (RTS) received due attention the world over following the earthquake, which jolted Wenchuan County in Sichuan Province of China on 12th of May 2008. It is alleged that the earthquake was responsible for the death of over 60,000 people. Following the event, a major question raised was whether the earthquake was related to the impoundment of the nearby Zipingpu reservoir or even the Three Gorges reservoir on the river Yangtze. Reservoir-triggered seismicity (RTS), also referred to as reservoir-induced seismicity (RIS), is the triggering of earthquakes by the physical processes that accompany the impoundment of large reservoirs. As far as dam building and subsequent creation of reservoir in the north-eastern region of India is concerned, this aspect bears significance as the region falls under Seismic Zone-V characterized by frequent seismic activities due mainly to geological formations. Although there are a number of different views on the issue of RTS, it is envisaged that the ongoing discussion presents a review of such events across the globe and emphasizes the importance of the seismic safety of dams, while promoting further research on the subject.