The 2015 Nepal Earthquake, as observed from Valentia
The 2015 Nepal earthquake (the Gorkha earthquake) occurred at 11:56 local time (06:11:26.9 UTC) on 25 April with a moment magnitude (Mw) of 7.8. Its epicenter lied in Barpak village of Gorkha district; approximately 80 km to the northwest of Kathmandu, the capital of Nepal. Its hypocenter was at a depth of approximately 15 km (9.3 mi) (which is considered shallow and therefore more damaging than quakes that originate deeper in the ground).
Valentia Observatory seismic trace
A major aftershock of magnitude 6.7 Mw occurred on 26 April 2015 in the same region at 12:55 local time (07:09 UTC), with an epicenter located about 17 km (11 mi) south of Kodari, Nepal. The aftershock caused fresh avalanches on Mount Everest and was felt in many places in northern India. Aftershocks will be expected for months ahead.
According to USGS, the April 25, 2015 M 7.8 Nepal earthquake occurred as the result of thrust faulting on or near the main frontal thrust between the subducting India plate and the overriding Eurasia plate to the north. At the location of this earthquake, approximately 80 km to the northwest of the Nepalese capital of Kathmandu, the India plate is converging with Eurasia at a rate of 45 mm/year towards the north-northeast, driving the uplift of the Himalayan mountain range. Although a major plate boundary with a history of large-to-great sized earthquakes, large earthquakes on the Himalayan thrust are rare in the documented historical era. Just four events of M6 or larger have occurred within 250 km of the April 25, 2015 earthquake over the past century. The largest, an M 8.0 event known as the 1934 Nepal-Bihar earthquake, occurred in a similar location to the 1988 event. It severely damaged Kathmandu, and is thought to have caused around 10,600 fatalities.
Nepal says 6,204 people are known to have died in the 7.8-magnitude quake and 13,932 were injured. But the fate of thousands more in many remote areas remains unknown and the government has warned that the death toll could rise to more than 10,000. In the worst affected areas as many as 90% homes have been destroyed and also temples and other historic buildings have been levelled according to BBC channel on 1st May 2015.