Scientists discover hidden landscapes “frozen in time” under Antarctic ice for millions of years

Scientists revealed on Tuesday that they had discovered a vast, hidden landscape of hills and valleys carved by ancient rivers that have been “frozen in time” under the Antarctic ice sheet for millions of years.

This landscape, larger than Belgium, has remained untouched for potentially more than 34 million years, but human-driven global warming could threaten to reveal it, the British and American researchers warned.

“It’s an undiscovered landscape – no one has seen it.” Stewart Jamiesona glaciologist at UK’s Durham University and lead author of The studiotold AFP.

“What’s exciting is that it’s been hiding there in plain sight,” Jamieson added, stressing that the researchers hadn’t used new data, just a new approach.

The land beneath the East Antarctic ice sheet is less well known than the surface of Mars, Jamieson said.

The main way to “see” under it is for an overhead plane to send radio waves into the ice and analyze the echoes, a technique called radio-echo.

“We are now on our way to developing atmospheric conditions similar to those that prevailed” between 14 and 34 million years ago, when it was three to seven degrees Celsius warmer (about seven to 13 degrees Fahrenheit) than at present, they wrote in the journal Nature Kommunikation.

Nature communication

But doing this across the continent – Antarctica is larger than Europe – would pose a huge challenge.

So the researchers used existing satellite images of the surface to “trace the valleys and ridges” more than two kilometers below, Jamieson said.

The undulating ice surface is a “ghost image” that gently drapes over these pointed features, he added.

When combined with radio-echo sounding data, a picture emerged of a river-carved landscape of plunging valleys and sharply peaked hills similar to some currently on Earth’s surface.

It was like looking out the window of a long-haul flight and seeing a mountainous area below, Jamieson said, comparing the landscape to the Snowdonia area in north Wales.

The area, which stretches over 32,000 square kilometers (12,000 square miles), was once home to trees, forests and probably animals.

But then the ice came and it was “frozen in time,” Jamieson said.

Exactly when sunshine last touched this hidden world is difficult to determine, but scientists are certain that at least 14 million years have passed.

Jamieson said his “hunch” is that it was last exposed more than 34 million years ago, when Antarctica first froze.

Some of the researchers had previously found a city-sized lake beneath the Antarctic ice, and the team believes there are other ancient landscapes down there that have yet to be discovered.

Tipping point for a “runaway reaction”

The authors of the study said global warming could pose a threat to their newly discovered landscape.

“We are now on our way to developing atmospheric conditions similar to those that prevailed” between 14 and 34 million years ago, when it was three to seven degrees Celsius warmer (about seven to 13 degrees Fahrenheit) than currently, wrote those in the journal Nature communication.

Jamieson emphasized that the landscape is hundreds of kilometers inland from the edge of the ice, so any possible exposure would be “far away.”

The fact that retreat of ice over earlier warming events — such as the Pliocene period three to 4.5 million years ago — did not expose the landscape was cause for hope, he added.

But it remains unclear what the tipping point would be for a “runaway response” of melting, he said.

The study was released a day after scientists warned that the melting of the nearby West Antarctic Ice Sheet is is likely to accelerate significantly in the coming decadeseven as the world meets its ambitions to limit global warming.

Earlier this year, a massive chunk of Antarctica’s Brunt Ice Shelf — a chunk the size of two New York cities — got away.

The Brunt Ice Shelf lies across the Weddell Sea from the site of another ice shelf that has made headlines, the Larsen C Ice Shelf on the Antarctic Peninsula. Last year Larsen C ice shelf – which was roughly the size of New York City and was long considered stable – collapsed into the sea.

Glacier experts have warned that some of the world’s largest glaciers could disappear within a generation without a dramatic reduction in greenhouse gas emissions.

Traditionally, glacial ice builds up during the winter and provides vital water for crops, transit and millions of people on several continents during the summer as it slowly melts and feeds rivers.

“They make it very visible,” Matthias Huss, head of GLAMOS, an organization that monitors glaciers in Switzerland and collected data for the academy’s report, told CBS News last month. “People can really understand what’s happening with huge glaciers disappearing and shrinking. This is much more impressive than seeing another graph of rising temperatures.”

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