34-Million-Year-Old Lost Antarctic River Discovered by Scientists, Offering Rare Picture of Continent's Land

Scientists were able to discover a river the size of Rio Grande that used to dominate West Antarctica and flow roughly 44 to 34 million years ago.

This discovery of the long-lost river could offer a rare picture of the land on the continent that is presently covered in ice.

Lost Antarctic River

The waterway, which spans 900 miles, is believed to have flown roughly 44 to 34 million years ago. This was briefly before the incredibly thick ice sheet on the continent started to build up.

Back then, long before human life entered the picture and after dinosaurs roamed over the earth, Antarctica's climate was mild. It possibly housed giant penguins.

The river discovery also implies that back then, West Antarctica sat above sea level.

Study author Cornelia Spiegel from the University of Bremen explained that they discovered that before ice covered West Antarctica, a massive river system dominated it. The area also used to have a temperate climate and swampy environment.

Spiegel added that the river could have meandered through a vast plain on the coast, with boggy swamplands through its river banks.

Discovering the Long-Lost River

A global team of scientists found evidence of the lost Antarctic river after they analyzed sandstone rock samples under the Amundsen Sea Embayment. This is where the Ice Sheet of West Antarctica gets in touch with the ocean.

In the rock from the Eocene period, which went on from roughly 56 to 34 million years ago, the researchers were able to discover evidence of sediments from the Transantarctic Mountains. This implied that an ancient river washed them all the way to the area.

The researchers were also able to find organic chemical traces linked to freshwater bacteria. This supported a large river delta presence within the area.

The delta could have apparently stretched between the West Antarctic Ice Sheet and the Transantarctic Mountains and ended up draining into the Amundsen Sea. This was noted in the "A large-scale transcontinental river system crossed West Antarctica during the Eocene" study.

Spiegel noted that their study shows that West Antarctica used to mostly sit above sea level while being quite flat at the same time. Due to the missing topography, the area stayed free of large glaciers.

As for East Antarctica's mountainous areas, they started freezing roughly 34 million years ago.

The scientists are hopeful that the long-lost river's discovery could help shed light on their understanding of the geography of Antarctica and how it ended up as a frozen continent today.

The researchers noted that major Antarctic glaciations started the Eocene-Oligocene transition 34 million years ago. This marked one of the most pronounced climate transitions in the Phanerozoic.

They also noted that the reconstruction of the conditions of Antarctica prior to this condition offers crucial boundary conditions to understand the glaciation onset and subsequent cooling with major ice sheet modeling consequences.

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