Manipur lies in the same greater Himalayan seismic fault-line as Nepal and Hindu Kush in Afghanistan, but scientists say it would be wrong to link Monday’s magnitude-6.7 earthquake and the other two big quakes in the region in the last nine months.
“I would be extremely wary of trying to find any relation among the three earthquakes and attempt to reach conclusions like big earthquakes are increasing in frequency in this area,” Vineet Gehlot of National Centre for Seismology said.
Nepal suffered a magnitude-7.8 quake on April 25 and the Hindu Kush area one of magnitude 7.5 on October 26. The nearly 2,500-km greater Himalayan seismic belt runs from Hindu Kush to Arunachal Pradesh and further down into Southeast Asia.
“Earthquakes are geological processes and it would be wrong to make any conclusions based on events over one or two years, in fact even over a decade. You need much larger datasets, over a few hundred years in the least, to be able to make any worthwhile deductions of such nature,” Gehlot said.
The epicentre of Monday’s earthquake was located in what is known as the “Indo-Burmese arc”. In a more populous area with larger houses, the earthquake could have cause more damage. “The construction in this area is largely traditional. There are no highrise buildings, houses are flatter. It is also very sparsely populated area,” he said.
Sankar Kumar Nath of IIT Kharagpur said the area is “one of the deadliest earthquake-prone zones in the world”. Some of the biggest earthquakes in India in the last 100 years, including in Shillong in 1897 and in Assam in 1950, have happened in the northeastern region. The 1934 earthquake on the Bihar-Nepal border had also caused widespread devastation in this region.
“Today’s earthquake was big but not a great earthquake which is greater than 8 in magnitude. The total amount of energy released was equivalent to about 11 Hiroshima-kind atom bombs,” Nath said.
He said the area has the potential to produce much larger earthquakes, though earthquakes cannot be predicted. “It is good that some energy has been released in the form of a relatively smaller earthquake. That will, hopefully, give the fault some time to accumulate greater stress for a bigger earthquake.”