Can liquid water persist within an ice sheet?

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Scientists have discovered a large aquifer, the size of Ireland, near the surface of the Greenland Ice Sheet. “This was a big surprise,” said Jason Box, a researcher for the Geological Survey of Denmark and Greenland, “because we were drilling before melt had begun.” So liquid water had to survive since at least the previous year. Such water storage within the ice had not been previously considered, not on this massive scale. How can a giant reservoir of water exist inside a frozen ice sheet? Continue reading

Are scientists conservative about sea ice?

The U.S. Coast Guard Cutter Healy encountered only small patches of sea ice in the Chukchi Sea when this photograph was taken on July 20, 2011. (Courtesy NASA Goddard Space Flight Center)

The U.S. Coast Guard Cutter Healy encountered only small patches of sea ice in the Chukchi Sea when this photograph was taken on July 20, 2011. (Courtesy NASA Goddard Space Flight Center)

Guest post by Walt Meier, NSIDC Scientist

Arctic sea ice set a record minimum extent in September 2012, far below the previous record low in 2007. Summer extents have been far lower than average for the last decade, with several record or near-record years. Looking at the numbers, one is tempted to think that the Arctic Ocean may reach nearly sea ice-free conditions within just a few years. But most expert analyses indicate that we’re likely at least a couple decades away from seeing a blue Arctic Ocean during the summer.

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Are Greenland’s galloping glaciers slowing down?

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One of the three major ice streams studied, the outlet of the Jakobshavn-Isbræ glacier produces about 10 percent of Greenland’s icebergs due to calving. Located in West Greenland, its icebergs float down the fjord, sometimes getting stuck in shallower waters for years. Though the glacier’s acceleration rate has fluctuated through the years, it is still a major contributor to Greenland’s ice loss. Courtesy Spencer Weart, flickr (http://www.flickr.com/photos/weartpix/4077525679/)

For the past decade, Greenland’s ice sheet has been losing its ice more rapidly, raising concerns about its contribution to sea level rise. A recent study, published in Nature, proposes that Greenland could slow its shedding of ice from its massive ice sheet into the ocean. “This doesn’t mean glacial recession and melting will slow,” said Faezeh M. Nick, a glaciologist from the University Centre in Svalbard in Norway. Nick’s study points out that the problem is not so straightforward. Continue reading