NASA Images Reveal Huge New Crack on Greenland's Petermann Glacier

A huge new crack has appeared on the Petermann Glacier, a large ice shelf in northern Greenland. NASA images show the rift has opened up at the center of the floating ice shelf and, should it continue to grow, it could break off into a large iceberg and float away.

NASA took the aerial images of the glacier on April 14 as part of its Operation IceBridge mission. This aims to better understand how the polar regions are connected to the global climate system. Researchers chart changes in the thickness of sea ice, ice sheets and glaciers, as well as looking at how the Earth's poles respond to climate change.

Normally, cracks in ice shelves appear near the edges, where the ice is thinner. The location of the new crack at the center of the Petermann Glacier makes it of particular concern. It means another process must be causing the ice shelf to thin. Scientists believe there could be warm water sitting beneath the ice shelf, but say they will need to undertake further research to confirm this.

NASA also highlighted another, older rift on the ice shelf near the new one. This, scientists say, "may exert a stagnating effect on the propagation of the new rift toward the older one," meaning that the two rifts could join together to form one huge crack.

However, scientists can't tell yet whether or not this will result in a giant chunk of ice breaking away from the ice shelf—known as a calving event.

The Petermann Glacier has undergone two major calving events within the last decade. In 2010, an iceberg measuring 97 square miles broke away. Dubbed an ice island, at the time it was the largest iceberg to form in the Arctic in almost 50 years.

In 2012, another iceberg measuring 50 square miles broke away from the ice shelf. At the time, Eric Rignot of NASA's Jet Propulsion Laboratory, said in a statement: "The floating extension is breaking apart. It is not a collapse but it is certainly a significant event."