As rescue teams searched Thursday for missing people following catastrophic flooding along the Nepal-China border, earth scientists reviewed satellite imagery for clues to the cause and assessed the devastation.The flooding killed hundreds of people in Nepal and Tibet on Wednesday. Many more are still missing, including scores of foreigners and pilgrims. Geomorphologists Kristen Cook and Dan Shugar said initial images from Nepal on Wednesday were obscured by clouds and dust from the debris, so they could only see that part of a glacier had broken off from the Langtang Lirung peak, near the border with Tibet. In clearer images from Thursday, they said they could see that the bedrock underneath the glacier had collapsed, taking the massive chunk of ice down with it and sending boulders and ice into the valley.“It shows the whole area without anything hidden, and we could see that, yes, it looked like there was not only this glacier that had failed, but a much larger chunk of the bedrock of the mountainside itself that had given way,” said Shugar, associate professor at the University of Calgary. “You have this big bedrock failure that took part of the glacier with it.”
Shugar said it’s heart-wrenching to look downstream from there on the images, to where people were living, and see how the debris has buried villages. After slamming to the valley floor, the debris maintained its momentum through the steep, narrow valley as ice melted, said Cook, at the Université Grenoble Alpes in France. Water and mud several stories high swept through communities.
