Glacier sheared off, plunged 1.2km before ‘liquid concrete’ flood swamped Nepal

Nearly two-thirds of a high-altitude glacier near the Nepal-Tibet border sheared away and plunged about 1.2km into the Lhende Khola river catchment Wednesday. This triggered a chain reaction in which falling ice gathered rock, snow and sediment, temporarily blocked the river and then released a debris-laden torrent into the Bhote Koshi-Trishuli corridor, satellite analysis and scientists’ assessments showed. The collapse occurred on the Nepalese side of the border.Satellite images analysed by Isro’s national remote sensing centre showed that almost two-thirds of the glacier body had detached. A Sentinel-2 image from Aug 24 showed the glacier intact, while a Landsat-9 image taken after the disaster on Aug 26 revealed a large scar identified as the “zone of glacier breakage and collapse”. The images also traced a broad ice-rock avalanche path descending towards the river.The scale of the fall was crucial to what happened next.