This image of a Patagonian glacier was aqcuired by the Advanced Spaceborne Thermal Emission
and Reflection Radiometer (ASTER) on May 2, 2000. Patagonia is a mountainous region spanning
the border between Chile and Argentina near the southern tip of South America. The image covers an
area of 36 x 30 kmthe full-size image has a resolution of 15 meters per pixel. Vegetation appears red in the image, which is a false-color composite of near-infrared, red, and green light displayed as red, green, and blue, respectively.
This large glacier is riddled with crevassesdeep cracks in the ice. The semi-circular
ridge at the far left of the image is composed of rock and soil carried there by the glacier
which was even larger in the past. This type of feature is called a terminal moraine. The pools of water at
the foot of the glacier are light-colored due to the fine silt suspended in them. A braided stream
winds through more silt deposited by the glacier and cuts through the terminal moraine about one third
of the way down from its top. Along the right side of the image are a series of parallel valleys
that were likely cut by arms of the glacier which have since receded.
Tyndall Glacier is located in the Torres del Paine National Park in Chile. This glacier, which has a total area of 331 square kilometers and a length of 32 kilometers (based on 1996 measurements), begins in the Patagonian Andes Mountains to the west and terminates in Lago Geikie.
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.