Water And Oceanography

How Ocean Currents Speed Melting of Antarctic Ice



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The speed at which Antarctic Ice is melting has recently been determined to be increasing. The increase in the speed of the melting is being attributed to ocean currents.

Loss of glacier ice has been poorly understood in the past

In a 2007 report from the British Antarctic Survey, details emerged about the profound loss of Antarctic glacier ice, particularly in the Western Antarctic, where some of the fastest thinning Antarctic glaciers are located. Researchers at the time had utilized satellite lasers to give researchers a more comprehensive picture of thinning glaciers. Researchers hoped to use their findings for more accurate future predictions of sea levels.

Calling the glacier thinning “dynamic thinning” researchers determined that thinning had penetrated deeper into the ice shelf than previously determined or thought to be occurring. Lead author of the British Antarctic Survey, Dr. Hamish Pritchard, said that “This kind of ice loss is so poorly understood that it remains the most unpredictable part of future sea level rise.” Researchers did suspect, however, that warmer ocean currents may be to blame for faster melting of Antarctic Ice and faster glacier flow.

Researchers made discoveries regarding melting of Antarctic glaciers

Citing a new study in Nature Science, Science Daily indicates that “stronger ocean currents beneath West Antarctica’s Pine Island Glacier Ice Shelf is melting the ice from below, speeding the melting of the glacier as a whole.” In 2009, researchers ascended upon the Amundsen Sea to study thinning ice shelves. They wanted to determine changes since a 1994 expedition in the area the Pine Island Glacier Ice Shelf. What they found when a robot submarine descended below the surface of the ice shelf was that a glacier had detached from an underwater ridge, allowing warmer, deeper ocean waters to then gain access to deeper parts of the glacier. As warmer water continued flowing into the deeper areas of the glacier, ice-melt water flowed out, thinning the ice even more. The speed at which the glacier was sliding into the sea was accelerated.

Other glaciers in that particular region of the Antarctic are also thinning. It was determined that the speed at which ice is melting has increased fifty percent in the fifteen years between the two expeditions.

Ocean currents are determined to cause increase in speed of melting Antarctic Ice

The Antarctic region has also been getting windier in recent years, which may contribute to changes in ocean currents, say researchers. Even though ocean temperatures have risen very slightly, the small increase is not enough to account for the increase in the speed at which glaciers are melting in the Antarctic region.

Eric Rignot, University of California at Irvine Professor and Senior Research Scientist at the NASA Jet Propulsion Laboratory says that experts think that the presence of warm waters is the main cause of the increase in the speed at which Antarctic ice is melting. Rignot stated that “Warm waters did not get there because the ocean warmed up, but because of subtle changes in ocean circulation. Ocean circulation is key. This study reinforces that concept.”  


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ARTICLE SOURCES AND CITATIONS
  • InfoBoxCallToAction ActionArrowhttp://www.sciencedaily.com/releases/2009/09/090923143331.htm
  • InfoBoxCallToAction ActionArrowhttp://www.sciencedaily.com/releases/2011/06/110626145308.htm
  • InfoBoxCallToAction ActionArrowhttp://www.oceanleadership.org/2011/ocean-currents-speed-melting-of-antarctic-ice-a-major-glacier-is-undermined-from-below/