East Antarctic Ice Sheet has fewer lakes underneath it than scientists thought

Nov. 7 (UPI) -- The East Antarctic Ice Sheet has far fewer lakes beneath it than scientists once assumed.

During an Antarctic expedition, a team of researchers from the Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, or AWI, observed that areas underneath Recovery Glacier contained only few large bodies of water.

This new findings were published Wednesday in the Journal of Geophysical Research.

Previous research used satellite remote sensing to detect a number of lakes beneath the surface of Recovery.

The glacier sits in the Coats Land region of Antarctica, from which an ice stream moves toward Weddell Sea at a rate ranging from 10 to 400 meters annually. The drainage area reaches more than 600 miles inland from the Filchner Ice Shelf, which is on the coast. In the past, scientists thought that subterranean heat melted the glacier, creating the large lakes that caused the ice stream to move.

The AWI team's research now casts doubt on that theory. They expected to find bodies of water larger than Lake Constance based on the satellite data, but research from the expedition turned up nothing but more questions.

"From satellite imagery of the glacier we can see, especially in the upper drainage basin, several flat, uniform areas on the surface. We had previously assumed that there were giant lakes below them that initiated the ice stream. Without these lakes, it was believed, streams like the Recovery Ice Stream could never form," Angelika Humbert, first author of the study and head of the AWI's Glaciology section, said in a press release.

Other research from Russian and British scientists confirms the existence of subglacial lakes created by melting. Their research conducted from Lake Vostok and Lake Ellsworth confirm that fact.

"These lakes are accumulations of meltwater, which is created when subterranean heat begins melting the ice from below. Over thousands of years, the water slowly gathers in these depressions," said Thomas Kleiner, AWI glaciologist and co-author of the study.

But the AWI team is unsure whether lakes played a role in creating the Recovery ice stream.

"To be on the safe side, we also used satellite data and double-checked the previously detected changes in elevation, which are an indicator of flooding lakes," Humbert said. "Though we can reproduce the findings of our colleagues, and can certainly understand why they expected to find lakes there, we simply weren't able to confirm the presence of water at the respective locations."