Scientists Identify Collapsed Glacier as Cause of Nepal-Tibet Floods

Preliminary investigations indicate that a collapsed glacier is responsible for the flash flood on the Nepal-Tibet border, according to scientists. Initial reports suggested that an earthquake had triggered a landslide, leading to the flood that has resulted in at least 177 fatalities. However, the US Geological Survey clarified that the disaster was due to a "glacial collapse," which occurs when a glacier or part of it disintegrates. The impact of the collapsed glacier registered a magnitude of 5.2, as reported by USGS data and scientists analyzing the event. Dr. Simon Cook, a glacier expert at the University of Dundee, noted that his team detected the collapse of the lower part of a glacier near Langtang Lirung peak, approximately 15 kilometers (9 miles) west of the flood site. He estimated the glacier collapsed in a northwesterly direction and traveled downstream. An analysis by the International Centre for Integrated Mountain Development (ICIMOD) suggested that an ice-rock avalanche from a high-altitude area contributed to the disaster, sending a large volume of debris into the Lende Khola, a tributary of the Bhote Koshi river. This caused a sudden surge in the river, raising water levels by seven to nine meters within 30 minutes, damaging several water monitoring stations. Professor Mike Searle from Oxford University explained that the process from landslide to flood could have taken hours or days, with the debris wave indicating a possible initial landslide that dammed the river before bursting. The steep topography of the area may have intensified the flood's impact. The cause of the glacier's collapse remains unclear, but Searle noted that the Himalayas are rising due to tectonic movements, which can destabilize glaciers. He emphasized that while smaller glacier collapses are common, the complete collapse observed in this instance is unusual. Searle attributed the event to a combination of tectonic uplift and climate change, which is causing glaciers to melt at an accelerated rate. ICIMOD's analysis earlier this year indicated that glaciers in the Hindu Kush Himalaya are losing ice at double the rate since 2000, increasing flood risks. Similar incidents have occurred in India, Switzerland, and Italy, with a notable glacier collapse in India's Chamoli valley in 2021 resulting in 200 deaths. Mohd Farooq Azam from ICIMOD highlighted the growing visibility of hazards in the cryosphere, linking the pattern of such events to climate change. Dr. Cook remarked that a warming planet is likely to lead to more frequent landslides, debris flows, and glacier collapses, destabilizing high mountain environments.