Jakobshavn Glacier Calving Front Recession from 1850 to 2006

Jakobshavn Isbrae is located on the west coast of Greenland at Latitude 69 N. The ice front, where the glacier calves into the sea, receded more than 40 km between 1850 and 2006. Between 1850 and 1964 the ice front retreated at a steady rate of about 0.3 km/yr, after which it occupied approximately the same location until 2001, when the ice front began to recede again, but far more rapidly at about 3 km/yr. After 2004, the glacier began retreating up its two main tributaries: one to the north, and a more rapid one to the southeast.
These changes are important for many reasons. As more ice moves from glaciers on land into the ocean, it causes a rise in sea level. Jakobshavn Isbrae is Greenland's largest outlet glacier, draining 6.5 percent of Greenland's ice sheet area. The ice stream's speed-up and near-doubling of the ice flow from land into the ocean has increased the rate of sea level rise by about .06 millimeters (about .002 inches) per year, or roughly 4 percent of the 20^th century rate of sea level increase.