Along Greenland's western coast, a small field of glaciers empties into Baffin Bay, 80% of which is covered by ice in winter. Calving icebergs may be seen in the lower right of this high-resolution satellite photo. Baffin Bay is only 1,000 m (3,300 ft) deep along the coast. Between May and July a polynya, an area of navigable open water surrounded by sea ice, forms at the northern part of the bay. This polynya, the largest in the Canadian Arctic, is stable in location and has existed for nearly 9,000 years. Image courtesy of USGS.

The Petermann Glacier grinds and slides toward the sea along the northwestern coast of Greenland, terminating in a giant floating ice tongue. Like other glaciers that end in the ocean, Petermann periodically calves icebergs. In July 2012, a massive ice island broke free and gradually drifted down the fjord, away from the floating ice tongue from which it calved. This satellite image has been rotated and north is toward the right. Analysis of the image reveals that the iceberg covers an area of about 32.3 sq km (12.5 sq mi). Image courtesy of NASA.

The calving front of Petermann Glacier in northern Greenland as seen from a NASA P-3B. In July 2012 an iceberg twice the size of Manhattan broke off of Petermann Glacier and began to float away in the ocean. After this calving event the line where the iceberg broke away became the glacier's new front edge, or calving front, effectively moving it several kilometers upstream. Credit: NASA/Michael Studinger.

The calving front of Kangerdlugssup Glacier in central west Greenland where icebergs are born. You can see several large ice bergs in the fjord on the right surrounded by the so called mélange, which is a dense mix of bergy bits and sea ice floating in the fjord. The mélange plays a role in how many ice bergs a glacier can produce by stabilizing the calving front. Credit: NASA/Michael Studinger.

Sunrise at Kangerlussuaq, Greenland, with ravens on the left, and the Watson River and Sugarloaf Hill seen through a haze of windblown glacial silt. Credit: NASA/Jim Yungel.

Frozen fjord along northeast coast of Greenland as seen from a P-3 aircraft on 14 May 2012. Credit: NASA/Jim Yungel.

A frozen fjord downstream of the Violingletscher (Violin Glacier) in eastern Greenland. Image courtesy of NASA/Michael Studinger.

Sea water off the east coast of Greenland looked a bit like marbled paper in October 2012. The shifting swirls of white were sea ice, as observed by satellite. Thin, free-drifting ice moves very easily with winds and currents. Each year, Arctic sea ice grows through the winter, reaching its maximum extent around March. It then melts through the summer, reaching its minimum in September. By October, Arctic waters start freezing again. However, the ice in this image is more likely a remnant of old ice that migrated down to the coast of Greenland. Sea water is unlikely to start freezing this far south in October. Photo courtesy of NASA.

Each spring and summer, as the air warms up and the sunlight beats down on the Greenland ice sheet, sapphire-colored ponds spring up like swimming pools. As snow and ice melt atop the glaciers, the water flows in channels and streams and collects in depressions on the surface that are sometimes visible in satellite imagery. These melt ponds and lakes can disappear quickly - a phenomenon that scientists have observed firsthand in recent years. Photo courtesy of NASA.

The Steensby Glacier in norothern Greenland flows around a sharp bend in a deep canyon. The glacier is located at 81 degrees north in Nyboe Land and flows into the St. Georges Fjord. Credit: NASA/Michael Studinger.

This image of Saunders Island and Wolstenholme Fjord with Kap Atholl in the background was taken during a NASA Operation IceBridge survey flight in April of 2013. Sea ice coverage in the fjord ranges from thicker, white ice seen in the background, to thinner grease ice and leads showing open ocean water in the foreground. Credit: NASA/Michael Studinger.

The coast of Greenland as seen from the air.

Glaciers in the fjords of Greenland, as seen from the air.