Nepal-Tibet Glacier Collapse: Massive Ice Avalanche Triggers Deadly Flash Floods

A catastrophic glacier collapse in the Himalayas has triggered one of the deadliest disasters of the week along the Nepal-China border, sending a massive wall of ice, rock, mud and water through mountain valleys and devastating communities on both sides of the frontier.

The disaster started on Wednesday, August 26, when a large section of glacier and surrounding rock on Langtang Lirung mountain collapsed at an altitude of around 5,200 metres.

The debris plunged roughly 1,200 metres into the valley, generating a huge avalanche and flood that travelled downstream through the Lhende Khola, Bhote Koshi and Trishuli river systems.

Glacier Collapse Was Initially Mistaken For An Earthquake

The scale of the collapse was so huge that the seismic signal was initially interpreted as an earthquake.

However, analysis by the U.S. the Geological Survey later found out that the seismic waves originated from the glacier and the landslide itself.
According to the USGS, the collapse released energy equivalent to a magnitude 5.2 earthquake.

The dramatic scale of the disaster was captured on video by a tourist in Gyirong County in China's Xizang (Tibet) Autonomous Region.

The footage shows a huge mass of ice, rock and debris racing down the mountain before surging through the valley.

Videos from the area also showed torrents of mud and water engulfing buildings and sweeping away vehicles within seconds.

The destruction extended to Gyirong Port, an important China-Nepal border crossing. Roads, buildings and other infrastructure were damaged, while communications and power supplies were disrupted.

The USGS said the debris flow travelled nearly 100 kilometres and affected populated areas downstream, including the vital China-Nepal transport corridor.

Flood Wave Tore Through Nepalese Settlements

After crashing into the valley, the enormous volume of ice, rock and water entered the river system and raced downstream into Nepal.
The Trishuli River rose by as much as 9 metres in only 30 minutes, according to reports. Settlements including Timure and Syapru Besi in Rasuwa district suffered extensive destruction, while homes, bridges, roads, hydropower facilities and other infrastructure were swept away or buried under debris.

Death Toll And Missing Persons

The human toll is difficult to find out because rescue teams are still struggling to reach some of the worst-hit areas.

As of August 29, Reuters reported that at least 669 people had died in Nepal and seven in Tibet, while approximately 3,000 people were missing. Around 540 foreign nationals were among those missing, with many believed to have been travelling through the region as pilgrims or tourists. Around 90 U.S. citizens are also reported to be among those missing, according to the latest Associated Press reporting.