A research published in Nature Communications managed to identify 85 previously unknown subglacial lakes beneath the icy surface of the South Pole, raising the total number of known active lakes in Antarctica to 231.
The discovery was made possible thanks to the analysis of 10 years of data from the CryoSat satellite, operated by the European Space Agency (ESA).
Invisible ecosystems: lakes beating beneath kilometers of ice
Their dynamics influence the movement of glaciers and the rising sea level.
Hidden beneath the largest ice mass on Earth, these subglacial lakes are part of a dynamic structure that affects the stability of glaciers and, therefore, the global sea level.
Some of them are active, meaning they fill and drain cyclically, allowing the study of internal processes of the ice sheet.
“Before our study, only 36 complete filling and draining cycles had been observed. Now we add 12 more,” explained Sally Wilson, lead author and researcher at the University of Leeds.
Satellite technology: how to detect lakes under the ice
The scientific team used observations from CryoSat to detect variations in ice elevation, which rises and falls according to the behavior of subglacial lakes.
These changes allowed them to map new drainage pathways and discover five interconnected lake networks, revealing a subglacial hydrology more complex than expected.
Meltwater: geothermal heat and friction as hidden drivers
Subglacial flow can accelerate ice movement towards the ocean
Subglacial meltwater is generated by heat from the bedrock and friction of moving ice. This water accumulates and periodically drains, reducing friction between ice and rock, facilitating glacial sliding towards the ocean.
This process has direct implications on ice sheet stability and global ocean circulation.
Lake Vostok: the sleeping giant under East Antarctica
Contains up to 65,000 km² of water under 4 km of ice.
The largest known subglacial lake is Vostok, located beneath East Antarctica. Although considered stable, its eventual drainage could alter the ice sheet, affect marine habitats, and modify the sea level.
Its water volume is enough to fill the Grand Canyon and overflow it by 25%.
Climate models and glacier monitoring: keys to the future of the planet
Subglacial data improve the understanding of interactions between ice, rock, ocean, and atmosphere.
The filling and draining cycles of these lakes constitute a valuable dataset for climate models.
By monitoring these phenomena, scientists can better predict the evolution of ice sheets, understand their interactions with the environment, and anticipate climate change scenarios.
