More high-intensity earthquakes likely in region: Experts

NEW DELHI: While opinion is sharply divided over whether Tuesday's temblor was a fresh earthquake or an aftershock of the 7.9 that hit Nepal in April, experts are worried there may be more high-intensity earthquakes that could affect the region in the coming few months.

Dr A L Ramanathan, professor of environmental geology, JNU, says the Indian plate has been active and release of energy in the form of earthquakes and aftershocks measuring 6.5 and above on the Richter scale is likely to continue over the next few months.

"The faults in the zone covering Afghanistan, Nepal, India and Pakistan have been activated. The area from the Himalayas up to Uttarakhand may experience some activity in the coming months," he said.

Dr C S Dubey, professor, department of geology, Delhi University, added that while predicting the exact time and location of an earthquake is not possible, there are three seismic gaps where stress has been increasing. "These are between Kashmir and Himachal Pradesh, parts of east Uttarakhand, and between Bhutan and Arunachal Pradesh where a mega earthquake is waiting to happen. In fact, there may be many more mega earthquakes in the Himalayan region," he says.

India Meteorological Department says Tuesday's quake is an aftershock of the massive one felt on April 26. Dr L S Rathore, DG, Met, said the temblor was centered in the same zone as the previous one and aftershocks can go on for several days.

"It is my opinion that this was an aftershock. However, there are two schools of thought. It will take a couple of months to study this and say for sure," he said. However, those calling it a fresh earthquake say that it is too big and occurred after too long to be an aftershock.

Devesh K Sinha, head of department (Geology) at DU, says, "Tuesday's quake was 7.3 on the Richter scale, almost as high as the one felt in April. The epicenter of both quakes is also different-this latest one is closer to Mt Everest. This is definitely not an aftershock," he said.

So much activity in the earth's crust around Nepal is being caused by the sudden release of energy that has been accumulating for years in the rocks below the surface due to movement of the Indian plate towards the north, under the Eurasian plate.

Dr Saumitra Mukherjee, professor (geology and remote sensing), JNU, explains: "The Indian plate has been moving by 5-6 cm each year towards the Eurasian plate. The movement causes build-up of energy in the rocks. Once the rocks give way, there is an earthquake.

In this particular region, the release of energy in the form of an earthquake last occurred some 80 years back. Now, the rocks have no longer been able to retain the pressure and have crumbled, causing the quake. The aftershocks are results of the plates settling down. However, analysis has shown that despite two big earthquakes, all energy has not been released"