- Scientists say they’ve identified 56 lakes beneath the Greenland ice sheet, bringing the total to 60 known subglacial lakes underneath the thick ice mass.
- While some of these lakes are just 200 meters (650 feet) long, some are nearly 6 kilometers (3.7 miles) in length.
- There are probably many more such subglacial lakes under the Greenland ice sheet waiting to be uncovered, the researchers say.
Until recently, researchers knew of four lakes lying hidden underneath the Greenland ice sheet. Now, scientists say they’ve identified 56 more, bringing the total to 60 known subglacial lakes beneath the thick ice mass. While some of these lakes are just 200 meters (650 feet) long, some span nearly 6 kilometers (3.7 miles) in length, a new study has found.
Jade Bowling, lead author of the study and a graduate student at Lancaster University, U.K., and her colleagues analyzed more than 574,000 kilometers (357,000 miles) of radio echo sounding data collected by NASA’s IceBridge program and identified 54 subglacial lakes. To get radio echo sounding data, specially equipped aircraft send radio waves that penetrate thick ice. The signals that come back can be used to interpret a glacier’s internal structure, including pinpointing locations where there might be liquid water. The researchers identified an additional two lakes using another set of elevation model data set called ArcticDEM.
“This study has for the first time allowed us to start to build up a picture of where lakes form under the Greenland Ice Sheet,” Bowling said in a statement. “This is important for determining their influence on the wider subglacial hydrological system and ice-flow dynamics, and improving our understanding of the ice sheet’s basal thermal state.”
Unlike the lakes under the Greenland ice sheet, subglacial lakes under the Antarctic ice sheet are relatively better known. Researchers have detected more than 400 such lakes to date, the largest being Lake Vostok, which stretches for more than 250 kilometers (155 miles).
“Researchers have a good understanding of Antarctic subglacial lakes, which can fill and drain and cause overlying ice to flow quicker. However, until now little was known about subglacial lake distribution and behaviour beneath the Greenland Ice Sheet,” Bowling said.
There are probably many more such subglacial lakes under the Greenland ice sheet waiting to be uncovered, the researchers say. “There is little doubt that our inventory, although representing a significant augmentation of the number of identified lakes, is incomplete and further subglacial lakes remain to be discovered,” they write in the paper.
Moreover, some of the lakes that the study has detected could be worth investigating further, study co-author Stephen J. Livingstone, a senior lecturer at the University of Sheffield, U.K., said in the statement.
“These lakes could provide important targets for direct exploration to look for evidence of extreme life and to sample the sediments deposited in the lake that preserve a record of environmental change,” Livingstone said.
Citation:
Bowling, J. S., Livingstone, S. J., Sole, A. J., & Chu, W. (2019). Distribution and dynamics of Greenland subglacial lakes. Nature Communications, 10(1). doi:10.1038/s41467-019-10821-w