Bigger quakes may hit Himalayas again

 

The earthquake on April 25 was found to have originated at a depth of 17km. The main shock rupture started about 80 km north-west of Kathmandu and progressed from under the capital city. 

Scientists from the Indian Institute of Science and Education Research have estimated that the total rupture area caused by the earthquake may be about 8,376 square km. 

 

A team of scientists, led by Dr S. Mitra of the Department of Earth Sciences, at the IISER-Kolkata, have conducted the study. It is already known that the Indian seismic plate is colliding with the Eurasian seismic plate at the rate of nearly 5 cm per year. The collision between the two plates is the “convergence” between India and Tibet. Because of this convergence, immense seismic energy is stored as elastic strain energy in the region. “This confirms that majority of the convergence between India and Tibet is stored as elastic strain energy only to be released by brittle failure in earthquakes,” Dr S. Mitra said in his study. Earthquakes are a means of releasing such seismic energy stored within the faults. 

 

Further, the scientists said, that about two-thirds of such energy is yet to be released. “It was found that over two-thirds of the accumulated energy still remains to be released. This excess stored energy is capable of driving a few magnitude 8.2-8.6 earthquakes in the Himalayas.” Scientists say that other segments in the Himalayas too have unrelieved energy and could be sites for future earthquakes.