Beneath the thick ice cover of Antarctica, water flows continuously through a hidden network. Deep under the frozen crust, lakes form and drain through unseen channels. Now, using satellite data collected over the past decade, scientists have discovered 85 new active subglacial lakes beneath Antarctica.
Discovery Increases Total Active Lakes
According to a study published in Nature Communications, this discovery raises the total number of active subglacial lakes in Antarctica from 146 to 231. Scientists believe this finding not only expands the existing map but also reveals how highly interlinked the subglacial water network is.
A Hidden Water System Beneath the Ice
These new lakes lie deep under several kilometres of Antarctic ice and cannot be studied directly on the ground. Therefore, experts monitored their activity by analysing data from the European Space Agency's CryoSat-2 spacecraft, collected from October 2010 to July 2020. The study involved nearly 15 billion measurements of ice elevation. Small rises and falls in the ice surface allowed experts to determine lake activity: filling caused slight elevations, while draining caused depressions.
Scientists registered 37 drainage events and 34 filling events, confirming that these lakes are active. The European Space Agency notes that subglacial lakes are particularly difficult to detect because they lie far below Antarctica's surface and may change gradually over months or years.
More Connected Than Expected
Another crucial finding is that most lakes appear to be connected through a network of drainage channels underneath the ice sheet. The researchers mapped five subglacial lake networks and 25 subglacial lake clusters in Antarctica. Some lakes showed simultaneous draining of upstream lakes and filling of downstream lakes, suggesting hidden channels linking them.
It was also found that 73 of the newly discovered active lakes are in East Antarctica and 12 in West Antarctica, indicating active subglacial hydrological systems throughout the continent.
Additionally, the researchers created what they call the first time-evolving boundary dataset, comprising all 85 lakes, enabling scientists to track changes in their size over time.
Why Water Exists Beneath Frozen Antarctica
Despite extreme cold, several mechanisms produce meltwater under the ice. Geothermal heating from rocks beneath Antarctica melts ice from below. Friction from large ice sheets moving against the ground also generates additional meltwater. This water accumulates and moves through underground channels, forming active lakes.
Satellite images have confirmed many active subglacial water systems under Antarctica and Greenland. Subglacial meltwater can act as a lubricant on the bottom of an ice sheet, affecting glacial behaviour.
Why the Discovery Matters
This finding is crucial because hidden water beneath Antarctica could directly impact ice flow. Subglacial lakes and drainage networks may influence glacier stability and movement, key factors in predicting long-term sea levels. Water under the ice can reduce resistance, allowing some ice sheets to flow faster toward the ocean.
Scientists say subglacial hydrology remains one of the least understood aspects of current ice-sheet models. An accurate map of these lakes could improve predictions of Antarctic ice behaviour.
The discovery also indicates that past studies of hidden lakes may have been partially successful. Most importantly, it changes how we view Antarctica: no longer a silent, stationary ice chunk, but a dynamic system of lakes and rivers constantly moving beneath the surface in total darkness.
