Besides the world’s tallest peaks, the Himalayan Mountain Range holds thousands of glaciers. In southern China, just north of the border with Nepal, one unnamed Himalayan glacier flows from southwest to northeast, creeping down a valley to terminate in a glacial lake. On December 25, 2009, the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this natural-color image of the glacier.
Mountains on either side of the glacier cast long shadows to the northwest. From a bowl-shaped cirque, the glacier flows downhill. Where the ice passes over especially steep terrain, ripple marks on the glacier surface indicate the icefall. Northeast of the icefall, the glacier’s surface is mostly smooth for several kilometers until a network of crevasses mark the surface.
At the end of the glacier’s deeply crevassed snout sits a glacial lake, coated with ice in this wintertime picture. Just as nearby mountains cast shadows, the crevassed glacier casts small shadows onto the lake’s icy surface. This glacial lake is bound by the glacier snout on one end, and a moraine—a mound formed by the accumulation of sediments and rocks moved by the glacier—on the other.
NASA Earth Observatory image created by Jesse Allen, using EO-1 ALI data provided courtesy of the NASA EO-1 team. Caption by Michon Scott based on image interpretation by Bruce Raup, National Snow and Ice Data Center.
Acquired December 25, 2009, this natural-color image shows a glacier slowly creeping down a valley to terminate in a frozen lake.
Although they move slowly, glaciers do move, and this movement alters the ice as it passes over land. Likewise, a moving glacier can carry with it evidence of geologic events it has witnessed. The Bear Glacier in the Kenai Peninsula along the Gulf of Alaska bears multiple clues about its past.