Deep under Antarctica’s thick ice cover lies a hidden world of lakes that no human has ever seen.
These “subglacial lakes” sit several kilometers below the surface and play a critical role in the way the ice sheet moves, which in turn affects the stability of glaciers and global sea levels.
Now, thanks to satellite data, scientists have discovered 85 new lakes beneath the frozen continent, boosting the number of known active lakes to 231.
The discovery was made using information collected over a decade by the European Space Agency’s CryoSat satellite.
Launched in 2010, CryoSat measures the thickness of polar sea ice and monitors changes in the height of massive ice sheets in Antarctica and Greenland.
Its radar instrument is sensitive enough to detect subtle rises and falls on the ice surface—clues that lakes deep below are filling with water or draining away.
Subglacial lakes are not static bodies of water. Some of them are “active,” meaning they regularly drain and refill in cycles that take months or even years.
These changes cause the ice above to sink or rise by a few meters, which satellites like CryoSat can detect. Before this study, only 36 complete cycles of filling and draining had been observed worldwide.
The new research, published in Nature Communications, recorded 12 more, increasing the total to 48.
Lead author Sally Wilson, a doctoral researcher at the University of Leeds, said observing these changes is extremely difficult because the lakes are hidden beneath hundreds of meters of ice.
“It is incredibly difficult to observe subglacial lake filling and draining events in these conditions, especially since they take several months or years to fill and drain,” she explained. The new satellite data, however, allowed scientists to track these changes across Antarctica from 2010 to 2020.
The study also identified new drainage pathways under the ice, including five networks of interconnected lakes.
Anna Hogg, a co-author of the study and professor at the University of Leeds, said the findings show Antarctica’s hidden water systems are far more dynamic than previously thought. “It was fascinating to discover that the subglacial lake areas can change during different filling or draining cycles,” she said.
Understanding these lakes is important because they can influence how quickly glaciers slide toward the ocean. Meltwater forms at the base of the ice sheet due to heat from Earth’s interior and friction as the ice shifts across bedrock.
This water can pool to form lakes, which occasionally drain, reducing friction and allowing the overlying ice to move faster. This process could have major implications for sea level rise.
Not all lakes are active. Some, like Lake Vostok—buried under four kilometers of ice and holding more water than the Grand Canyon—are thought to be stable. Still, scientists warn that if a giant lake like Vostok were ever to drain, it could disrupt ocean circulation, marine ecosystems, and ice sheet stability.
Wilson emphasized that most climate models do not currently account for subglacial hydrology. “By mapping where and when these lakes are active, we can start to quantify their impact on ice dynamics and improve projections of future sea level rise,” she said.
The research highlights the value of long-term satellite observations. Martin Wearing, ESA’s Polar Science Cluster Coordinator, said, “The more we understand about the complex processes affecting the Antarctic Ice Sheet, including the flow of meltwater at its base, the more accurately we will be able to project the extent of future sea level rise.”
For now, the hidden lakes of Antarctica remain out of reach for direct exploration. But thanks to satellites, scientists are piecing together the secret life of water beneath the world’s largest ice sheet—and what it might mean for the planet’s future.
Source: KSR.
