NASA reports that measurements taken from orbiting satellites indicate the Greenland ice sheet underwent melting over a larger area than they've seen in 30 years of observations. On July 8, the satellites found evidence that about 40% of the ice sheet's surface had melted. Observations just four days later showed 97% of the surface had melted. "This extreme melt event coincided with an unusually strong ridge of warm air, or a heat dome, over Greenland. The ridge was one of a series that has dominated Greenland's weather since the end of May. 'Each successive ridge has been stronger than the previous one,' said Mote. This latest heat dome started to move over Greenland on July 8, and then parked itself over the ice sheet about three days later. By July 16, it had begun to dissipate. Even the area around Summit Station in central Greenland, which at 2 miles above sea level is near the highest point of the ice sheet, showed signs of melting. Such pronounced melting at Summit and across the ice sheet has not occurred since 1889, according to ice cores analyzed by Kaitlin Keegan at Dartmouth College in Hanover, N.H. A National Oceanic and Atmospheric Administration weather station at Summit confirmed air temperatures hovered above or within a degree of freezing for several hours July 11-12." Photos also surfaced last week showing the Petermann Glacier in Greenland 'calving' — some very large chunks of it broke off and started to drift away.