Greenland Ice Sheet Undergoes Unusual Melting

Data from three satellites show the massive ice sheet covering the Arctic territory of Greenland underwent an unusual melting earlier this month.

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.