Glacier-capped Mountains in Tibet
Image showing part of a glacier-capped mountain chain about 110 kilometres west-north-west of the Tibetan city of Lhasa. In this false-colour image, snow-free ground appears reddish-brown, snow and ice appear white, and water varies in colour from navy to aquamarine. Because the Sun’s angle is low in this wintertime shot, the mountain ridges cast long shadows toward the north. The large, nearly black area spread across the centre of the image is a shadow. The network of jewel-toned lakes in the upper left quadrant of the image likely originates from a small glacier obscured by the shade. Other lake-producing glaciers, however, sit in the sunshine, visible in the upper right and lower left quadrants of the image. Many glaciers are muddied by dirt and rocks they have ground off surrounding terrain. Besides two deep blue lakes, smaller water bodies the colour of aquamarine fringe the glaciers and pool downstream of the larger lakes. Like other water bodies, glacial lakes can vary in colour depending on water depth, sediment, or both. Glacier-fed lakes are often brightly coloured because of glacial flour—fine sediments that come from the powerful grinding action of glaciers on underlying rocks. This file is in the public domain because it was created by NASA.