Into the abyss
Fractures and draining lakes are weakening the Greenland Ice Sheet.
Each summer, lakes of meltwater form on the surface of the Greenland ice sheet, eventually draining away through fractures in the ice. Until recently, glaciologists believed such melting would have only a superficial effect on the health of the ice sheet as a whole.
New research, however, has found that the warm water carried down through the fractures can cause a cascading effect, leading to near-simultaneous draining of large networks of such lakes reaching far inland. When the meltwater reaches the base of the ice sheet, it can also melt and weaken the structure of the ice there.
In the image above, a scientist is abseiling into one such fracture to investigate more closely.