Earth Observations taken by the Expedition 16 Crew

ISS016-E-012047 (22 Nov. 2007) --- Tyndall Glacier, located in the Torres del Paine National Park in Chile, is featured in this image photographed by an Expedition 16 crewmember on the International Space Station. This glacier, which has a measured total area of 331 square kilometers and length of 32 kilometers (1996 measurements), begins in the Patagonian Andes Mountains to the west and terminates in Lago Geikie. A medial moraine is visible in the center of the glacier, extending along its length (center left). These accumulations of soil and rock debris form along the edges of a glacier as it flows downhill across the landscape (much like a snowplow builds ridges of snow along the roadside). Glaciers flowing downslope through adjacent feeder valleys merge when they encounter each other, and debris entrained along their sides becomes concentrated in the central portion of the new combined ice mass -- much as small streams join to form a river. Crevasse fields are also visible in the image. The crevasses -- small, but potentially quite deep fissures -- form as a result of stress between slower- and faster-moving ice within the glacier. Crevasse fields on Tyndall Glacier are most evident near rock promontories extending into the glacier -- causing the ice to slow as it flows around the obstruction.