Researchers discovered a hidden Antarctic landscape under a layer of ice over a mile thick that shows how different the continent looked millions of years ago

• Researchers recently found an "undiscovered landscape" beneath Antarctica's ice.
• The continent once looked very different and was much warmer.

Millions of years ago, Antarctica looked very different. Instead of a mostly ice-covered continent, it was a landmass with free-flowing rivers and glacier-carved valleys.

But between 14 million and 34 million years ago, an ice sheet crept across the continent. It locked some of the lush landscape beneath over a mile of ice, per NBC News.

That landscape remained hidden for millennia until now.

"It is an undiscovered landscape," glaciologist Stewart Jamieson and lead author of a study on the new discovery, told Agence France-Presse. "No one's laid eyes on it."

Tropical Antarctica

Jamieson and his fellow researchers looked at an area of the continent that was about 12,000 square miles wide, a little smaller than the state of Maryland, and located about 186 miles inland from the Eastern Antarctic coast.

The ancient, slow-moving ice eroded much of Antarctica's features. However, in this region, the ice wasn't thick enough to do the same damage. Instead, the ice may have helped preserve the landscape.

"Suddenly, that landscape is frozen in time," Jamieson told Live Science. The findings were published in Nature Communications this month.

Jamieson and his colleagues looked at previously collected satellite images and radio-echo sounding data from East Antarctica.

RES is a technique that uses radio waves to determine the thickness of ice. This helped the researchers determine the height of peaks and depths of valleys that lay hidden beneath the ice.

There's still a lot more to be revealed about the area, like the type of plants and animals that may have lived there. About 50 million years ago, palm trees grew in Antarctica, according to a 2012 study.

"Depending how far back in time you go, you might have had climates that ranged anywhere from the climate of present-day Patagonia through to something more approaching tropical," Jamieson told NBC.

A rewarming Antarctica

It's crucial to understand how warming temperatures will impact Antarctica's ice.

Earlier this week, a separate paper found that the continent's West Ice Shelf may melt even if countries meet climate-change goals. That scenario could cause sea levels to rise by 17 feet, per The Guardian.

Jamieson noted that ice melting and revealing the newly discovered landscape is "a long way off."

However, learning more about the area and how its ice responded to previous warming events could offer important clues to researchers about what to expect from the current climate crisis.