Study details Greenland's ice sheet plumbing system

EXETER, England, Oct. 9 (UPI) -- Researchers from the University of Exeter think subglacial lakes will be more frequently drained as global warming continues.

In a new study published in the journal Nature, scientists detail the plumbing systems that fill and drain the subglacial lakes found beneath Greenland's ice sheet.

Researchers used satellite images to plot changes in a specific subglacial lake over the last two decades. They found Greenland's subglacial lakes are distinct from subglacial lakes in Antarctica.

"Our research reveals details about the plumbing system beneath the Greenland ice sheet, which is important because the configuration of that system has an impact on the flow speed of the overlying ice," study author Steven Palmer, a geographer at Exeter, said in a press release.

In Antarctica, lakes are fed by meltwater from the bottom of glaciers. But satellite imagery showed the subglacial lake in Greenland is fed by surface meltwater, which flows through a vertical shaft called a moulin. The lake was last drained in 2011. A similar event happened in 1996.

Researchers think the lake's unique style of plumbing will allow faster more frequent draining events in the future, potentially making ice sheets more vulnerable to climate change.

"We have made the first observations of how the Greenland ice sheet responds to subglacial lake drainage, but more research is required to understand the long-term impacts of these events," Palmer said. "It is possible that draining subglacial lakes act to release the pressure at the ice sheet base, meaning that if they drain more frequently in the future, they may actually result in slower ice sheet flow overall."