Rock Avalanche Sends Flood Across Nepal‑Tibet Border, Study Finds

A massive rush of rock, ice and water slammed into the Nepal‑Tibet border, causing huge damage. The senior researcher at ETH Zürich, Dr. Mylène Jacquemart, says the event was not a typical ice‑lake flood. Satellite pictures show there were no lakes in the area that could have burst open.

Images now point to a huge rock avalanche that carried a glacier along. The slide involved a big chunk of mountain that had ice on top, and both fell together. As the mass raced downhill it swallowed the rivers, turning into a fast flood that gathered extra water and sediment.

The rock needed to split along weak lines, and the ground was frozen year‑round because of permafrost. When the frozen ground thaws, water can seep into cracks, raising pressure and weakening the rock. Heavy monsoon rain added meltwater, especially after snow quickly vanished from higher altitudes.

Jacquemart remains cautious about naming one exact cause. Ground shaking was recorded, but it came from the slide itself, not before it. She says there is not enough data yet to link meltwater or warming directly to the disaster.