Scientists discovered under the ice antarctica a vast and hidden landscape of mountains and valleys Carved by ancient rivers that remained “frozen in time” for millions of years.
This landscape, whose area is larger than Belgium, Remained intact for more than 34 million yearsHowever, British and American researchers warn that the current human-induced global warming process threatens to reveal this.
“This is an uncharted landscape, no one has seen it yet,” Stewart Jamieson, a glaciologist from Durham University (UK) and lead author of the study, told AFP.
Emphasizing that the researchers did not use new data, just a new working system, Jamieson said, “The exciting thing is that it’s clearly hiding there.” he added.
The land beneath the East Antarctic ice sheet is less known than the surface of Mars, Jamieson said.
Using echoes from aerial and satellite imagery
The main methods used by scientists to “see” under the ice consisted of: Flying over it in an aircraft that sends radio waves to the frozen surface and then analyzes the echoesa technique called radio echo sounding.
But doing this for the entire continent (Antarctica is larger than Europe) would be an impossible challenge to solve. So researchers used Available satellite images of the surface Jamieson explained that they are working to map valleys and ridges located more than two kilometers below the ice.
When these satellite images were combined with radio echo data, a landscape image emerged. deep valleys and high hills ending in jagged peaks, similar to some mountain ranges currently present on the Earth’s surface. The valleys must have been shaped by the movement of ancient rivers.
“It was like looking out the window of a long-haul flight and seeing the mountain range below,” said Jamieson, who compared the view to the Snowdonia region of North Wales.
In this region of 32,000 square kilometers It was once a vast forest inhabited by forests and possibly animals. However, the scientist reported that ice later appeared and he was “frozen in time”.
It’s difficult to determine exactly when sunlight last touched this hidden world, but researchers are confident it was at least 14 million years ago. But Jamieson suspects it was last exposed to open air 34 million years ago, when Antarctica first froze over.
Some of the researchers involved in the expedition had previously found a city-sized lake beneath Antarctic ice, and the team believes there are other ancient landscapes in this region of Earth that have yet to be discovered.
climate threat
On the other hand, the authors of the study warn: global warming may pose a threat for this view newly discovered frozen.
“Now “We are on track to create atmospheric conditions similar to those that prevailed” between 14 and 34 million years ago.Scientists reported in the journal times when temperatures were three to seven degrees Celsius warmer than today. Nature. Communication.
However, Jamieson emphasized that the landscape is hundreds of kilometers inland from the ice edge, so any potential melting is out of the question. would still be “too far away” in time.
In fact, he added, it is a source of hope that the retreat of the ice during other warming events, such as the Pliocene epoch 3 to 4.5 million years ago, did not melt this area.
But it’s not yet clear what the tipping point would be if melting was a “runaway reaction” that occurred, he said.
The study was published a day after scientists warned. Melting of the neighboring West Antarctic Ice Sheet is expected to accelerate significantly in coming yearsEven if the world achieves its goal of limiting global warming.
Reference work: https://www.nature.com/articles/s41467-023-42152-2/figures/3
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