Greenland ice sheet (Credit: Joshua Brown/ University of Vermont)
Researchers at the University of Exeter have recently proposed a subglacial drainage pathway for a lake beneath the Greenland Ice Sheet. The lake in question is likely fed by meltwater from the surface that flows through supraglacial streams and collects in lakes on the surface.
Many of the lakes exist in a larger catchment area that drains into a deep hole in the ice called a moulin. As the water falls down, the researchers speculate that it fills the subglacial lake until a critical volume is reached and the water breaks a dam partially made of deformable sediment.
The researchers also found that the lake quickly refilled after a flood. According to the study, rising global temperatures could cause the periodic flooding of subglacial lakes to become a more common occurrence. Draining warm water from the surface to the middle and bottom of the glacier has the potential to alter how and how fast the glacier moves.
Top image: Greenland ice sheet (Credit: Joshua Brown / University of Vermont)