Three days after a violent earthquake struck Nepal’s Jajarkot region, killing at least a 150 people, a second quake, or an ‘aftershock’ struck the same region on Monday. Much like the November 3 earthquake, the tremors were felt as far away as Delhi though there were no reports of loss of lives, injuries and damage to structures.
“An earthquake of magnitude 5.6 was recorded in Nepal at 16:16,” said an alert from the National Centre for Seismology – Ministry of Earth Sciences. (NCS). No further details were available.
Following the November 3 quake, two aftershocks of magnitude M 3.5 and 3.8 were also recorded within a 10 km radius of the mainshock. “The area is seismically very active and associated with collisional tectonics where the Indian plate subducts beneath the Eurasian Plate,” according to a note from the NCS. One expert told The Hindu that Monday’s quake could also be considered an aftershock.
“There’s no hard definition for an aftershock. But given that it’s the same region and relatively close in time, it could be one. Look at what happened in Afghanistan,” V.K. Gahlaut, seismologist, National Geophysical Research Institute (NGRI), Hyderabad, told The Hindu.
A series of earthquakes over a week in October struck Afghanistan killing at least 1,000.
The November 3 earthquake was the deadliest in Nepal since a M 8 in 2015 which killed at least 8,000.
That quake was recorded by more than 60 seismic stations installed by NCS. The quakes occurred on the North Almora Thrust (NAT), a region suitably placed to trigger a ‘main-shock’ due to “...appreciable structural heterogeneity in and around mainshock,” the report noted.
The occurrence of earthquakes in the region is attributed mainly to the tectonic settings of the Himalaya comprising Himalayan Frontal Thrust (HFT), Main Boundary Thrust (MBT) and Main Central Thrust (MCT) besides several local faults and geological demarcated lineaments, according to the report.
