Agencies

New Delhi, October 05:

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.

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.