Greenland lake vanishes from climate warming

Global climate warming is being blamed for the melting of a vast lake in Greenland.

Researchers say that rising global climate temperatures are expected to cause an increase in meltwater in frozen expanses like the Greenland ice sheet, and this meltwater often forms sizable lakes.

Scientists have worried that when this increase in meltwater reaches the base of the Greenland ice sheet, it could further lubricate its slide over bedrock toward the sea, causing it to shrink more quickly than expected.

However, researchers at Woods Hole Oceanographic Institution in Massachusetts and the University of Washington found that while this surface melt indeed does lubricate the bottom of the ice sheet, that process by itself does not seem to be enough to cause catastrophic loss of an ice sheet mass.

Surface meltwater was responsible for only a small amount of the movement of six outlet glaciers that scientists have monitored.

In the summers of 2006 and 2007, the scientists used seismic instruments, water-level monitors and Global Positioning System sensors to study two such lakes and the motion of the surrounding ice sheet.

They also used helicopter surveys and satellite imagery to track the progress of glaciers moving toward the coast.