Researchers with a new study published in Nature have identified 85 new active subglacial lakes hidden beneath Antarctica’s deep ice. It’s a major discovery that adds to our understanding of how the continent’s hydrology process affects global sea levels. Sally F. Wilson, a doctoral researcher at the University of Leeds, was the primary author of the study. To do this, she relied on data from the European Space Agency’s satellites, CryoSat-2, which has been monitoring the Antarctic landscape over the last 10 years.
The study, recently published in Nature Communications, examined observations that were gathered between 2010 and 2020. These results indicate that the overall number of known active subglacial lakes in Antarctica has now increased to 231. These lakes remain secreted under hundreds of meters of ice. Intrigued by their deep impact on glacier movement and stability, scientists have long sought to understand their behavior.
The Importance of Subglacial Lakes
Subglacial lakes are created as meltwater pools up beneath the glacier. This is the result of geothermal heat emitted from the Earth’s bedrock, combined with frictional heat produced as ice slides over top of it. Examining this meltwater is crucial to answering important questions about how glaciers move and how they ultimately contribute to sea-level rise. Lake Vostok is currently the largest known subglacial lake beneath the East Antarctic Ice Sheet. It holds an estimated 5,000 to 65,000 cubic kilometers of water entirely frozen under four kilometers of ice.
These newly detected lakes form a key component of Antarctic hydrology. Wilson did not downplay the significance of these findings, noting in a press release,
“Subglacial hydrology is a missing piece in many ice sheet models.”
Understanding the dynamics of these lakes helps researchers quantify their impact on ice movements and improve projections regarding future sea level rise.
New Drainage Pathways Identified
Besides revealing new lakes to study, the research provided new insight into drainage pathways forming under the Antarctic Ice Sheet. This finding is important because it suggests that subglacial hydrology is more transient than previously thought. By identifying five interrelated subglacial lake networks, the study presents evidence for water flowing under ice in ways that computer models have long suggested.
This data is crucial for understanding how glaciers are changing in a warming climate. It further illuminates how they might threaten global sea levels in decades to come.
“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. Only 36 complete cycles, from the start of subglacial filling through to the end of draining, had been observed worldwide before our study. We observed 12 more complete fill-drain events, bringing the total to 48.”
This opening photo taken as part of my research provided a delivery mechanism: on any given filling or draining cycle, subglacial lake surfaces can vary greatly. Anna Hogg, a co-author of the study, commented on the implications of this discovery:
Dynamic Nature of Antarctic Hydrology
The lakes’ ever-evolving nature underscores the need for ongoing study. To truly understand their effects on ice dynamics, we need to keep a close eye on them and ascertain their impact.
“It was fascinating to discover that the subglacial lake areas can change during different filling or draining cycles. This shows that Antarctic subglacial hydrology is much more dynamic than previously thought, so we must continue to monitor these lakes as they evolve in the future.”
Martin Wearing, another contributor to the research, emphasized the value of CryoSat data:
Martin Wearing, another contributor to the research, emphasized the value of CryoSat data:
“This research again demonstrates the importance of data from the CryoSat mission to improve our understanding of polar regions and particularly the dynamics of ice sheets. The more we understand about the complex processes affecting the Antarctic Ice Sheet, including the flow of meltwater at the base of the ice sheet, the more accurately we will be able to project the extent of future sea level rise.”