Discovery of 930-Mile River Flowing Under Antarctica's Ice Stuns Researchers

Researchers have found evidence of a giant river system under the Antarctic ice, according to a new study.

A recent research article published in Science Advances covers the process by which the authors concluded that a giant river system existed in Antarctica during the middle-to-late Eocene period.

One of the objectives of the study was to understand how climate change has impacted the world across the decades, Live Science reported.

During the middle-to-late Eocene period, Earth's atmosphere changed drastically. Carbon dioxide dropped sharply leading to the formation of glaciers on an ice-free Earth. Experts aim to understand what triggered this climate change in those times.

In present times, carbon dioxide levels are increasing primarily because of human actions, Live Science reported. The aspect of climate change increases the relevance of the research for the experts.

The situations are also somewhat similar according to the researchers, Live Science reported.

Johann Klages, study co-author and a sedimentologist at the Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, in Germany, explained that the amount of carbon dioxide during the late Eocene period was almost double the amount Earth has at present.

Klages added that the amount will be equal in 150-200 years if the level of greenhouse gases continues to rise according to the prediction. 

"If we think about a potentially severe climate change in the future, we need to learn from periods in Earth's history where this already happened," Klages shared, Live Science reported.

The exploration in Antarctica has proven to be difficult, as most of the continent has been under ice, Live Science reported. The ice makes the process of accessing sedimentary rocks complicated, which is essential in the analysis of early environments.

The grains, minerals, and fossils trapped in the sedimentary rocks give experts an idea about what conditions transpired during a particular time.

In 2017, Klages and other scientists took advanced seafloor drilling equipment and reached the southernmost part of Chile, as per the study. The group drilled 100 feet (30 meters) into the seafloor and recovered sediments that contained layers from two separate periods.

On analysis, it was found that the lower part of the sediment was formed during the mid-Cretaceous period, about 85 million years ago. The upper part, on the contrary, had sand from the mid-to-late Eocene epoch, about 30 million to 40 million years ago. 

The Eocene layer had a stratified pattern which indicates that it arrived from a river delta, according to the study. To confirm their suspicions, the experts performed a lipid biomarker analysis. This test identifies the amount of lipid and sugar present in a layer.

During the test, they found a unique molecule which is generally found in cyanobacteria that live in freshwater. This finding made researchers conclude that an ancient river did once flow through the continent.

The researchers were able to trace the Eocene grains back to a distinct salt region in the Transantarctic Mountains, according to the study. This proved that the river flowed 930 miles (1,500 kilometers) before draining into the Amundsen Sea, in the continent.

"This is exciting — just having this exciting image in your brain that there was this gigantic river system flowing through Antarctica that is now covered by kilometers of ice," Klages said, Live Science reported.