Scientists uncovered beneath the ice of Antarctica a vast, hidden landscape of mountains and valleys carved by ancient rivers that have remained frozen in time for millions of years.
This landscape, larger in area than Belgium, stayed intact for more than 34 million years. Yet researchers warn that current human-driven warming could reveal it sooner rather than later.
“This is an uncharted landscape that no one has seen yet,” said Stewart Jamieson, a glaciologist at Durham University in the United Kingdom and the study’s lead author, to AFP. He noted that the team did not rely on new data but on a new analytical approach and emphasized, “The exciting thing is that it’s clearly hiding there.”
Image obtained from the region Nature
The land beneath the East Antarctic ice sheet is less understood than the surface of Mars, Jamieson noted.
Using echoes from aerial and satellite imagery
The primary methods scientists use to “see” beneath the ice involve flying over the continent and sending radio waves through the frozen surface, then analyzing the echoes in a technique known as radio echo sounding.
Mapping the entire continent would be an insurmountable challenge since Antarctica covers more ground than Europe. Instead, researchers used existing satellite images of the surface and are now working to map valleys and ridges that lie more than two kilometers beneath the ice, Jamieson explained.
When these satellite images were combined with radio echo data, a striking landscape emerged, revealing deep valleys and towering hills capped with jagged peaks. The valleys appear to have been sculpted by ancient rivers.
Valleys and mountains beneath ice Nature
“It was like looking out the window of a long-haul flight and seeing a mountain range below,” said Jamieson, who compared the view to Snowdonia in North Wales.
In a region spanning 32,000 square kilometers, the area was once a vast forested landscape, potentially home to animals. Ice later overtook the region, effectively freezing its history in time.
Determining exactly when sunlight last touched this hidden world is challenging, but researchers are confident it occurred at least 14 million years ago. Jamieson suggests it may have been as long as 34 million years ago when Antarctica first became enveloped in ice.
Some expedition members had previously discovered a lake beneath the Antarctic ice large enough to be considered city-sized, and the team believes other ancient landscapes lie within this region, awaiting discovery.
Climate threat
The study’s authors warn that global warming could threaten this newly revealed frozen world. They warn that atmospheric conditions may shift toward those seen between 14 and 34 million years ago, a period when temperatures were three to seven degrees Celsius warmer than today, as reported by the journal Nature Communications.
However, Jamieson stressed that the landscape lies hundreds of kilometers inland from the ice edge, making significant melting implausible in the near term. He also notes that past warming events, like the Pliocene epoch 3 to 4.5 million years ago, did not melt this area, offering some hope.
Scientists caution, though, that it remains uncertain what tipping point would trigger a runaway melting scenario.
The study appeared shortly after warnings that the nearby West Antarctic Ice Sheet could accelerate its melt in the coming years, even if global warming goals are met.
References: Nature Communications, https://www.nature.com/articles/s41467-023-42152-2/figures/3
……