It is a vast body of ice covering 1,710,000 square kilometres (660,000 sq mi), roughly 80% of the surface of Greenland. It is the second largest ice body in the world, after the Antarctic Ice Sheet. The ice sheet is almost 2,400 kilometres (1,500 mi) long in a north-south direction, and its greatest width is 1,100 kilometres (680 mi) at a latitude of 77°N, near its northern margin. The mean altitude of the ice is 2,135 metres (7,005 ft.

The last edge of the Greenland ice sheet that had resisted global warming has now become unstable, adding billions of tonnes of meltwater to rising seas, scientists said.