Explore Khumbu Glacier
Khumbu Glacier is the highest glacier in the world, flowing down from Mount Everest. It is approximately 17 km long and is walked alongside when trekking to Everest Base Camp. The lower part of the Glacier is heavily debris-covered which obscures the ice beneath. This glacier ice is 100s of metres thick in places and contains a network of englacial conduits which transport melt water through the glacier.
Much of the debris-covered area of Khumbu Glacier is now stagnant and is downwasting in situ in response to climatic warming (Figure 1), rather than retreating up-valley which is common of clean-ice glaciers or those terminating in water. Such surface lowering is common for heavily debris-covered Himalayan glaciers and means that when investigating glacier 'health' (e.g. annual mass balance), quantifying this vertical mass loss is very important.
Figure 1. Looking down towards the terminus of Khumbu Glacier where surface lowering is clearly visible. The surface of the glacier is pitted with supraglacial ponds and exposed ice cliffs.
The Khumbu Icefall flows from the Western Cwm and represents one of the most dangerous stages on the South Col route up Mount Everest. Following a deadly avalanche in 2014 the route through the icefall, which is maintained by a team Sherpas known as ‘ice doctors’, was moved to pass more centrally to limit avalanche exposure at the edge. However, the new route is longer, which means mountaineers will spend more time crossing the dangerous crevasses.
The crevasses form due to extensional flow as the glacier ice accelerates rapidly down the steep icefall. This stretches the ice, which opens up large crevasses and creates large and unstable blocks of ice known as seracs. These seracs collapse with little warning and cause intermittent avalanches in the icefall. The velocity of Khumbu Glacier can be derived by automatically tracking features on the surface using repeat satellite imagery.
Thermal data reveals the change in surface temperature with elevation, aspect and land cover.
Download the Khumbu Glacier information sheet here (two pages):
Click the blue icons for further information on the feature highlighted
Viewpoint 1. Looking across Khumbu Glacier:
If you zoom in close you will notice the surface is very uneven, with supraglacial ponds and exposed ice cliffs distributed across the surface. Thick debris cover insulates the ice beneath across much of the glacier's surface, but ponds and ice cliffs can locally increase the rate of melt.
Viewpoint 2. Gorak Shep:
A small village is located at Gorak Shep that provides lodges and other amenities for trekkers.