A New Rift Detected In One Of The Largest Greenland Glaciers

 

Stef Lhermitte, an assistant professor at the Delft University of Technology in the Netherlands, made a startling discovery this month. He was studying satellite images of the Petermann Glacier in Northwest Greenland when he discovered a new rift in the glacier. This was a startling find, as Petermann is one of the largest Greenland glaciers and one that already had major ice breakage in 2010 and 2012.

After sharing the information via Twitter, Lhermitte’s findings were confirmed by a NASA polar research team. Operation IceBridge was already mapping ice sheets in Greenland and Antartica, and the team did a flyover of the crack. They confirmed the find and used onboard technology to map it.The news had the potential to be alarming, in part because of the crack’s location. It is farther upstream than the previous two cracks that were located. This means that it’s further inland instead of on the edges, where most cracks form. If the new crack in the glacier were to meet with an existing one on the other side, the Peterman glacier could conceivable break in half.

While the melting of the Greenland glaciers poses no danger to sea levels, the glaciers protect the island’s ice sheet. If the crack causes “calving”, or the breaking off of a piece of the glacier, this could hasten the melting of the ice sheet. The danger of precipitous melting is a too-rapid rise in sea levels. This can lead to flooding and erosions of the coastlines.

One factor that mitigates the possible crisis is the existence of a “medial flowline”, a stream of water in the middle of the glacier. This stream softens the ice in its path, which helps halt the spread of the new rift.

“The shaded feature near bottom center is a medial flowline, whose presence may exert a stagnating effect on the propagation of the new rift toward the older one.”

The collaboration between climate scientists has allowed us to discover and monitor this new development. It can only be hoped that Greenland isn’t going to end up with another ice island like the 97-square-mile chunk that broke off from Petermann’s glacier in 2010.