Researchers from the University of Oslo have applied a technique to extract the detailed flow field of Khumbu icefall in the Nepalese mountains, from a large collection of Copernicus Sentinel-2 data — helping climbers ascend Mount Everest.
When high altitude mountaineers want to climb Mount Everest from the Nepalese side, they follow a route over and along Khumbu glacier. Part of the glacier, the icefall, runs over a steep cliff making it extremely dangerous.
Velocity patterns, generated by satellites, can be used to map dangerous areas on a glacier. But over the fast-moving icefall of Khumbu glacier, it has not been possible to observe glacier flow because the glacier ice funnels through a narrow corridor of rock, causing fracture ice to flow downward and making feature tracking difficult.
Thanks to the large dataset from the Copernicus Sentinel-2 mission, the researchers used a novel image matching technique, called ensemble matching, to generate a detailed high-resolution velocity map of glacier velocity – despite challenging image conditions.