An Earthquake Devastates Nepal

At 11:56 in the morning on 25 April 2015, a massive earthquake struck central Nepal. Centered near Barpak in Gorkha District, roughly 80 kilometers northwest of Kathmandu, the tremor measured 7.8 on the moment magnitude scale according to the United States Geological Survey. It originated at a shallow depth of about 8.2 kilometers on the Main Himalayan Thrust, the fault along which the India plate is pushed beneath the Eurasia plate. Early modeling suggested that the rupture extended roughly 120 kilometers eastward toward Kathmandu, releasing substantial seismic energy very close to the capital.

The earthquake struck a region with a long history of destructive shocks. According to the USGS, the India plate converges with Eurasia there at about 45 millimeters per year, a fraction of which drives the uplift of the Himalaya. Four earthquakes of magnitude 6 or larger had occurred within 250 kilometers of the 2015 epicenter over the previous century, including a magnitude 6.9 event in August 1988 that caused close to 1,500 deaths. The largest, the magnitude 8.0 Nepal-Bihar earthquake of 1934, severely damaged Kathmandu and is thought to have killed about 10,600 people. Nepal's National Planning Commission observed that the country had not faced a natural shock of comparable magnitude for more than 80 years.