A video shared by a photographer on Chinese social media and geolocated by CNN shows where a large section of a glacier near the summit of Langtang Lirung along the Nepal-China border has burst, causing devastating avalanches and landslides.
In his post, the photographer wrote that he heard the sound of falling glaciers around 10:30 a.m. local time on August 26, and at first thought it was a military exercise.
Wednesday’s glacier collapse was so strong that the U.S. Geological Survey initially reported it as a magnitude 4.4 earthquake.
Scientists compared satellite images before and after the disaster and proved that a huge chunk of glacier had been carved from high up in the mountain.
From there, it fell into the river below, a vertical drop of about 7,000 feet, a CNN analysis showed.
Information on the amount of rock and ice that fell is not yet available, but the section of glacier that collapsed was approximately 6,000 feet wide, and a similarly sized section of rock fell next to it.
The sheared glacier left a 3,000-foot-wide gash in the mountainside, according to a CNN analysis of satellite images.
Jeffrey Kargel, chief scientist at the nonprofit Planetary Science Institute, said the flood wave, made up of cascades of water, crushed ice and rock, “descended at an average speed of 193 kilometers (120 miles) per hour for the first 22 kilometers (13.7 miles).” That means you covered about 14 miles in just 6 minutes and 50 seconds.
Scientists have yet to determine the exact cause of the devastating floods.
CNN’s Laura Paddison and Thomas Bordeaux contributed reporting.
