Tuesday’s quake was ‘exceptional one’

The 7.3 magnitude earthquake that hit an already devastated Nepal was an aftershock that occurred quite close to the epicentre of the 1934 mega Nepal-Bihar earthquake and experts described it as an “exceptional one”.

The latter is the biggest earthquake recorded in the region. Seismologists say that the possibility of the occurrence of 7 magnitude quake again in the near future is very slim since aftershocks are generally lesser in magnitude than the original earthquake. However, smaller aftershocks are likely to continue for a few months.

The 1934 event was one of the worst earthquakes recorded in the history of Bihar and Nepal with a magnitude of 8.

The April 25 earthquake of Nepal, also known as Gorkha earthquake, was of magnitude 7.9. Hundreds of aftershocks have already been recorded since the April 25 earthquake with the one on Tuesday being the biggest of them all. Scientists had predicted that the probability of the occurrence of an aftershock, with magnitude in excess of 7, was just 7 per cent. “With nature, you can not rule out anything. After the Gorkha earthquake, the probability of a 7 magnitude earthquake was just 7 per cent. But it occurred,” Dr Srinagesh Davuluri, Chief Scientist, National Geo-physical Research Institute said.

“This earthquake occurred exactly on the opposite end of the Gorkha earthquake on the same fault,” Dr Srinagesh said. Scientists also described that Tuesday’s aftershock as an exception.

Dr N. Purnachandra Rao, Senior Principal Scientist, NGRI, said, “Aftershocks have to be smaller than the original earthquake. Most would be of magnitude 5 or 6. But now it is not so likely that we will see a large aftershock again.”