Images released Tuesday show the extent of surface melt on Greenland's ice sheet on July 8 (left) and July 12 (right). Measurements from three satellites showed that on July 8, about 40 percent of the ice sheet had undergone thawing at or near the surface. By July 12, 97 percent of the ice sheet surface had thawed.
A pair of NASA satellite images taken just four days apart tells a potentially worrying story of melting ice in the polar summer.
The first, snapped from orbit on July 8, shows about 40 percent of the Greenland ice sheet shaded in pink or red to illustrate probable or confirmed surface melting. The second photo, taken on July 12, shows nearly the entire land mass — 97 percent — blotched in a red hue.