The recent earthquakes in different parts of India, albeit of small magnitudes, have occurred due to foreshocks and swarms, a top official of the Geological Survey of India (GSI) said, warning that frequent tremors were a matter of concern in the subcontinent, where several areas are prone to major seismic activities. Dr Sandip Som, the deputy director general of GSI, also said that foreshocks — mild tremor preceding earthquakes — or swarm activities — series of earthquakes — indicate release of tectonic stress and strain during the continuous deformation process, and a detailed study of these jolts could help predict if a significant seismic event is in store.
“These minor earthquakes are mainly clustered in the north-eastern and north-western Himalayan region, around the Delhi-National Capital Territory (NCT), western Gujarat and Western Maharashtra areas which have been demarcated as seismic zones IV and V,” the geologist told PTI on Sunday. In the past, too, low-magnitude earthquakes have been recorded in these regions, he said. According to the GSI scientist, earthquakes in the north-eastern and north-western Himalayas occur along the plate convergence zones — between India and Eurasia.
