Satellite images expose catastrophic scale of Nepal glacier flood

On Wednesday, a glacier collapsed high in the Himalayan valleys above Nepal's Trishuli River, and what followed was a wall of water and debris that erased entire communities from the landscape. Satellite imagery released in the days after the disaster shows the catastrophic scope: villages gone, bridges snapped, a critical border crossing between Nepal and Tibet obliterated. More than 550 people are confirmed dead. Hundreds more remain missing.

The before-and-after photographs tell the story in spatial terms. At the Nepal-Tibet border crossing, one of the region's most important transit points, satellite data from the intelligence firm Vantor shows almost nothing left standing. Camera footage captured the moment the deluge swept over buildings as people fled. The force was so complete that damage and mud are visible more than 2.5 kilometers upstream from where the initial surge hit, with debris scattered 100 meters above the riverbed.

Downstream, the village of Timure has largely vanished. The valley walls there rise 50 meters above the water line, and satellite images show that most of the houses perched on that steep slope are now either gone or buried under mud. Further south, at Syapru Besi, where the Trishuli winds through a narrower section, the village is now covered by a blanket of mud, rock, and other debris. Bridges and a hydroelectric power station that once stood there have disappeared.

The town of Trishuli, located about 45 kilometers downstream from the border, was struck by the full force of the flood. Satellite imagery shows an entire neighborhood essentially washed away. Verified video footage from the ground captures the moment a bridge collapsed as the river surged forward. From inside a bus, people can be heard crying out in distress as they watched the water rushing toward them. In another video, residents sheltered inside a house, peering over a balcony as a torrent of floodwater and debris—including large metal objects and a vehicle—swept past. Remarkably, that house remained standing. In a second video taken after the water receded, survivors can be seen standing in the mud surrounding their home.

Satellite imagery from Planet Labs has also documented the disaster's origin point. A drone video captured the moment the glacier fractured and fell away, carving an enormous path of rock and debris down the valley. The satellite image shows the scale of the collapse: trees and vegetation have been stripped bare at heights exceeding 300 meters above the riverbed. This destructive corridor continues westward along the swollen river before turning south.

At the base of the landslide, a barrier lake has formed—a body of water trapped behind the debris. Chinese authorities have flagged this as a significant hazard, warning that a sudden drainage could trigger another wave of flooding. The lake has also complicated rescue operations. Dr. Argha Banerjee, a glaciologist at the Indian Institute of Science Education and Research, told BBC Verify that satellite images cannot determine how stable the barrier is or how likely the lake is to drain suddenly. However, he noted that the lake's surface area showed no significant increase between Wednesday and Thursday despite continued water inflow. A visible drainage channel suggests water is already escaping downstream, and the volume appears to have stabilized rather than growing alarmingly.

The extent of damage on the Tibetan side of the border remains largely unknown. That region, annexed by China in the 1950s, is strictly controlled and closed to foreign media. BBC Verify has been unable to locate verifiable footage from the area. The satellite imagery released by Vantor through its Open Data Program provides authorities with crucial information for directing rescue efforts, locating the missing, and recovering the dead—a first visual accounting of a disaster that has reshaped the landscape of an entire valley.