Investigators determined that a large rock and glacier-ice collapse on Langtang Lirung Peak in Nepal triggered a cascading hazard chain, forming new lakes and devastating valleys up to 100 km downstream. The event, which occurred on August 26, bears resemblance to the 2021 Chamoli disaster in India.
The Nepal event involved a mountain glacier of roughly 5 km², with a combined mass of rock and overlying ice falling from about 5,100 m to 3,700 m. The impact was felt approximately 100 km downstream, affecting numerous towns and villages and washing away roads and bridges. Several hundred workers are reported to be trapped in under-construction tunnels.
Questions remain about the trigger for the rock collapse and the source of the water. Researchers are currently modeling the flood to reconstruct the chain of processes. The Himalaya region’s fragile ecosystem, sensitive to climate change, faces increasing cryosphere instability. The lack of operational early warning systems in hazard-prone areas like Rasuwagadhi and Timure is highlighted as a critical failing, with the author emphasizing the need for a robust system for cryosphere-related hazards throughout the region.
Source: Down To Earth