New Analysis Reveals How Nepal's Deadly Disaster Began

New satellite imagery and video analysis are shedding light on the dramatic beginning of one of Nepal's deadliest natural disasters. Part of a glacier in the Himalayas near the Chinese border collapsed, triggering a massive flow of ice, rock and water that raced downstream at extraordinary speed, destroying everything in its path.

More than 600 people have died and nearly 2,500 remain missing, according to the latest figures. The disaster struck the area near the Nepal-Tibet border, with its destructive effects extending for more than 80 kilometres.

Scientists and the U.S. Geological Survey (USGS) determined that a roughly 0.2-square-kilometre section of ice broke away at an altitude of around 5,200 metres before plunging more than a kilometre. The impact generated a powerful shock that was initially detected by seismographs as a magnitude 5.2 earthquake.

The resulting torrent swept away at least 19 bridges and destroyed dozens of kilometres of roads, leaving numerous mountain communities cut off from the outside world. The danger may not yet be over, as a newly formed lake upstream has already begun to overflow.