The massive earthquake that devastated Nepal on Saturday released energy equivalent to explosion of 700 to 800 Hiroshima-type nuclear bombs, said leading geologist Harsh Gupta.
Meanwhile, the 7.9 magnitude temblor was described as a typical Himalayan earthquake caused by the collision of the Indian tectonic plate with the Eurasian plate, by Dr Ch Mohan Rao, director of Hyderabad-based National Geophysical Research Institute (NGRI), which keeps a tab on global seismic movements.
“Aftershocks are expected. Earthquakes in this region are quite expected and the largest earthquake of magnitude 8.4 occurred in 1934 on the Bihar-Nepal border, which was extremely destructive,” he said. The other major earthquakes of great magnitude in the Himalayas are the 1897 Shillong and the 1950 Indo-China earthquake, each with a magnitude of 8.7.
Harsh Gupta, former director of NGRI and also member of the National Disaster Management Authority, said the aftershocks of the earthquake could be felt for at least the next two to three months. As many as 15 aftershocks in the range of magnitude 5.0 and 6.6 were recorded in the region till 4:30 pm on Saturday, Laxman Singh Rathore, Director General of the India Meteorological Department said here.
Nestled in the Himalayan region, Nepal lies in the very high seismic zone that stretches 2,900 km from Kashmir in the north till Arunachal in the east, Gupta said. The region has witnessed four powerful earthquakes of magnitude 8.0 and above between 1897 and 1950. Gupta said the aftershocks of the great earthquake of 1950 continued for three years.
One of the highly active seismic zones in the world, the Himalayan region owes its very existence to the collision of the Indian and the Eurasian tectonic plates. The lofty Himalayan mountain ranges began to form between 40 and 50 million years ago when the two landmasses of India and Eurasia collided. Even today, the two plates collide into each other at an overall convergence rate of 5 cm per year.
The seismic waves due to the Nepal earthquake propagated across the Indian subcontinent and were felt in various parts of the country.