Warming Not Causing Greenland's Inland Lakes to Raise Ocean Levels

News about ice-melting often always evokes concerns of rising oceans. But researchers studying melting in Greenland have found that inland melting will not contribute to rise in ocean levels.

A team of researchers at MIT's Woods Hole Oceanographic Institution and elsewhere noted that increasing temperatures were causing the thick ice in the center of Greenland ice sheet to melt but the melt does not drain into the ocean. The finding is crucial as it would eventually predict how much ice-melting in Greenland would contribute to rising oceans. Greenland is second biggest ice sheet on Earth.

The findings were made after experts at institute studied how a lake called the North Lake, formed due to ice-melting in Greenland's coastal area, drained. The researchers identified vertical narrow channels in the ice called moulins, which caused the 2 km-wide North Lake to drain in hours.

"It is critical to understand how and why these lakes drain in order to predict how much mass the ice sheet will contribute to sea-level rise in our warming climate. We find that while lakes are forming inland, they probably won't drain by this mechanism," said Laura A Stevens a graduate student at MIT.

"The inland lakes will more likely drain their water via surface stream runoff, which transfers the water to the bed in more coastal areas of the ice sheet. So, while we see inland ice beginning to speed up as more melt happens inland, the draining of inland lakes likely won't exacerbate the situation."