Why glacial collapse likely caused the Nepal disaster—and why climate change will make these events more likely
The disaster has claimed hundreds of lives and at least 1,400 are missing
A catastrophic flood struck Nepal and Tibet, claiming hundreds of lives and leaving at least 1,400 people missing. The disaster occurred when a massive wall of water crashed through towns, tearing up buildings and infrastructure. Nepali officials believe the floods were caused by a glacial collapse, where a large piece of ice, rock, and debris suddenly detached from a glacier. This material may have dropped into a glacial lake and blocked a river, leading to the devastating flood.
Scientists say the glacier involved was a cirque glacier, which forms in a depression or basin high in the mountains. The event likely took place on Langtang Lirung, a 99th highest mountain in the world, located in the Langtang Valley, known as the "Valley of Glaciers." The glacial collapse may have been triggered by a rock avalanche, causing part of the glacier to fall into the Lende Khola river on the Nepal-Tibet border.
As the glacier and rock material fell, it gained energy and heat, accelerating further melting and contributing to the flood. Initial seismic data suggested an earthquake may have caused the collapse, but further analysis indicates the avalanche itself set off a magnitude 5.2 landslide. The U.S. Geological Survey confirmed the avalanche triggered the landslide, causing a dam to break and the subsequent flood.
Experts warn that climate change is making these events more likely. The Himalayas are experiencing rapid glacier melt, with Nepal losing a third of its ice volume in the past 30 years. Glaciers are now melting 65% faster in the last decade compared to the previous 10 years. While it's difficult to conclusively link a single event to climate change, scientists agree that melting glaciers, permafrost thaw, and altered precipitation and temperature patterns increase the likelihood of such disasters.
Human activity, including the construction of settlements, roads, pipelines, and shipping traffic in sensitive areas, further exacerbates the problem.
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