Superstorm Sandy sparked a lot of interest in rising sea levels when it swept across the Northeast last month and flooded parts of the coast. Over the next century, more water — and higher sea levels — could come from melting ice in Greenland and Antarctica. How much has been unclear.
But now scientists have developed a much clearer view of how quickly that ice has been melting over the past two decades. And that will help researchers forecast the rate of sea-level rise in the years to come.
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.
Credit AFP/Getty Images/NASA
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.
In these illustrations NASA produced from satellite data, the melt in Greenland on July 8 (at left) and July 12 are shown. According to NASA, "the areas classified as 'probable melt' (light pink) correspond to those sites where at least one satellite detected surface melting. The areas classified as 'melt' (dark pink) correspond to sites where two or three satellites detected surface melting."