Jakobshavn Isbræ

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Satellite image of Jakobshavn Isbræ. The coloured lines show the retreat of the calving front of the Jakobshavn Isbræ since 1850. The area stretching from the calving front to the sea in the bottom left corner is the Ilulissat icefjord. Courtesy of Nasa Space Observatory

Jakobshavn Isbræ, also known as the Jakobshavn Glacier and Sermeq Kujalleq (in Greenlandic) is a large outlet glacier in West Greenland. It is located next to the Greenlandic town of Ilulissat (Danish: Jakobshavn) at the Ilulissat Icefjord, approximately at 69°10′N 49°50′W.

Jakobshavn Isbræ is a major contributor to the mass balance of the Greenland ice sheet, producing some 10% of all Greenland icebergs some 35 billion tonnes of icebergs calved off and passing out of the fjord every year. Icebergs breaking from the glacier are often so large (up to a kilometer in height) that they are too tall to float down the fjord and lie stuck on the bottom of its shallower areas, sometimes for years, until they are broken up by the force of the glacier and icebergs further up the fjord. Studied for over 250 years, Jakobshavn Isbræ has helped develop our understanding of climate change and icecap glaciology.

It is also one of the fastest moving glaciers, flowing at its terminus at speeds of 20 to 22 metres per day. The rate has accelerated in recent years, probably due to global warming. The ice stream's speed-up and near-doubling of 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 20th century rate of sea level rise[1].

Satellite image showing the recent accelerating retreat of the calving front of the Jakobshavn Isbræ. Courtesy of Nasa Space Observatory

[edit] See also

• Retreat of glaciers since 1850
• Glacier mass balance

[edit] External links

• Fastest Glacier in Greenland Doubles Speed Article from NASA.
• Geological Survey of Denmark and Greenland Jakobshavn Isbræ,West Greenland: the 2002-2003 collapse and nomination for the UNESCO World Heritage List. Review of Survey activities 2003, issue 4, pp. 85-88.
• Ilulissat Icefjord. Book edited by Ole Bennike, Naja Mikkelsen, Henrik Klinge Pedersen and Anker Weidick, Geological Survey of Denmark and Greenland, 28th September, 2004, ISBN 87-7871-136-3
• 2004 velocity measurements incl. tidal effects Article from Dresden University of Technology.