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| Earthquake damage in Khokana, Lalitpur (Disaster Report photo) |
There is an increased risk of a future major earthquake in the west of Nepal and India region as April earthquake did not release all of the stress that had built up underground, Scientists warned.
The research is published in the journals Nature Geoscience and Science. The study found that the 2015 Nepal earthquake occurred on the Main Himalayan Thrust (MHT), the main megathrust fault along which northern India is pushing beneath Eurasia at a rate of about two centimeters per year, driving the Himalayas upward.
There are areas along the fault in western Nepal that are known to be locked and have not experienced a major earthquake since a big one (larger than magnitude 8.5) in 1505. But the Gorkha earthquake ruptured only a small fraction of the locked zone, so there is still the potential for the locked portion to produce a large earthquake.
"This is a place that needs attention, and if we had an earthquake today, it would be a disaster because of the density of population not just in western Nepal but also in northern India, in the Gangetic plain," BBC has written quoting Prof Jean-Philippe Avouac, from the University of Cambridge.
"If the earthquake had ruptured all the locked zone all the way to the front of the Himalayas, it would have been a much larger earthquake," said Prof Avouac.
The researchers believe that some of this stress has shifted west, to an area stretching from the west of Pokhara in Nepal to the north of Delhi in India.
The 7.9 magnitude earthquake that struck Nepal earlier this year killed about 9,000 people, and left many thousands more injured and homeless. This is the worst natural disaster to strike Nepal since the 1934 Nepal–Bihar earthquake.
Journal Reference:
Jean-Paul Ampuero et al. (2015). Lower edge of locked Main Himalayan Thrust unzipped by the 2015 Gorkha earthquake. Nature Geoscience. DOI: 10.1038/ngeo2518