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.
Currently 30.2 km long and between 0.5 and 2.5 km wide, Gangotri glacier is one of the largest in the Himalaya. Gangotri has been receding since 1780, although studies show its retreat quickened after 1971.
Because Indian glaciers have not been studied in detail for the past several decades, assessing their long-term trends has been difficult. More recent studies, however, suggest they are vulnerable to rising temperatures, which increased by 2.2 degrees Celsius (3.96 degrees Fahrenheit) between the 1980s and the new millennium.
This pair of images shows the retreat of the Sermersuaq (Humboldt) Glacier in northwestern Greenland between 2000 and 2008. Sermersuaq Glacier is the widest tidewater glacier in the Northern Hemisphere.
The Southern Patagonian Icefield of Chile and Argentina hosts several spectacular glaciers—including Grey Glacier located in the Torres del Paine National Park in Chile. This glacier, which in 1996 had a measured total area of 270 square kilometers and a length of 28 kilometers (104 square miles in area, 17 miles long), begins in the Patagonian Andes Mountains to the west and terminates in three distinct lobes into Grey Lake (upper image).