The Greenland Ice Sheet, 1.25 miles thick on average, is a frozen blanket that holds 8 percent of the world's fresh water. In the past month, researchers' efforts in the white North, including a new study in Science that looks at past aerial photography, have tried to uncover clues about how Greenland's ice works.
Scientists study the ice on the world's largest island to understand how it moves, melts, grows and shrinks. Ice loss has been accelerating in recent years. Measuring the rate at which ice and melted water join the ocean is critical for projections of global sea-level rise.
The Petermann Glacier is a river of ice in northern Greenland that opens into the Arctic Ocean. A large iceberg broke free on July 16 and began its drift down the fjord. A NASA satellite on July 21 captured this image of the iceberg, which covers an area of more than 46 square miles.
Read more energy & sustainability news.