What is a glacial collapse? The science behind the Nepal-Tibet floods

At least 469 people have died in Nepal and three in China’s Tibet after a sudden flood swept through communities along the Bhote Koshi and Trishuli river systems. More than 1,400 people remain missing. Scientists believe the flood was likely triggered by the collapse of a glacier and the rocks beneath it near Langtang Lirung, close to the Nepal-China border. The debris then moved downstream for nearly 100 km, carrying ice, water, boulders and mud.