Greenland Ice Sheet Undergoes Unusual Melting
This
satellite image from NASA shows the extent of surface melt over
Greenland’s ice sheet on July 8, 2012 (left) and July 12, 2012 (right).
July 25, 2012
The U.S. space agency NASA says the data shows 40 percent of the ice sheet, stretching from Greenland's coastal edges to its 3.2-kilometer-thick center, had experienced some thawing by July 8, and accelerated to 97 percent four days later. The ice melt was the largest detected in more than 30 years of satellite observations.
A scientist at Dartmouth College says such pronounced melting has not occurred since 1889.
NASA says the melting coincided with an unusually strong ridge of warm air, known as a heat dome, that parked itself over the ice sheet on July 11 and remained for about five days.
Scientists say they cannot determine whether the recent melting is a natural event or the result of man-made climate change.
Last week, a NASA satellite captured images of a huge iceberg measuring twice the size of New York City's Manhattan island breaking off from the Petermann Glacier, one of the largest in Greenland.
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