Scientists discover river system that flowed 40 million years under ice in Antarctica

Geologists have discovered an old river system that flowed about 40 million years ago under the enormous ice sheet of the West Antarctic. The discovery hints at the potential effects of major climate change on Earth and provides a glimpse into its past. The journal 'Science Advances' published their findings on June 5, 2024.

Earth's past climate changes

Study co-author Johann Klages, a sedimentologist at the Alfred Wegener Institute Helmholtz Center for Polar and Marine Research in Germany, said studying Earth's historical records of similar catastrophes is necessary to comprehend severe climate shifts in the future, as reported by 'Yahoo News'.
He observed that the Earth's atmosphere underwent major alteration in the middle to late Eocene epoch, approximately 34 million to 44 million years ago. When the Earth was free of ice, the decline in carbon dioxide levels prompted global cooling and the formation of glaciers.

Major climate event in Antarctica

An important climate event that occurred in Antarctica millions of years ago is of great interest to scientists, especially considering that the planet's carbon dioxide levels are rising due to human-caused climate change. The late Eocene epoch saw carbon dioxide levels that were almost twice as high as they are now, according to Johann Klages. According to him, Earth might attain comparable levels in 150–200 years if greenhouse gas emissions continue to rise.

Sediments from mid-Cretaceous period

In 2017, the research vessel Polarstern took Johann Klages and scientists on an expedition from Chile to West Antarctica. They extracted rock cores and sand from the icy seafloor using advanced drilling equipment.
By drilling nearly 30 meters (100 feet) under the ocean, scientists were able to uncover sediment layers from two different eras. The lower layer originated around 85 million years ago, during the mid-Cretaceous period, as per the radioactive dating of elements like lead and uranium. It contained fossils and pollen from a temperate rainforest of that time.

Sand dominated the mid-to-late Eocene sediments, which date from 30 to 40 million years ago. In-depth analysis showed Mississippi-like riverine layering resembling a delta. The concept of an ancient river system formerly flowing over Antarctica was supported by the discovery of a molecule characteristic of freshwater cyanobacteria, as confirmed by a lipid biomarker study.

River system under ice

With great excitement, Klages described the exciting idea of a vast river system that formerly flowed through Antarctica but is now buried below kilometers of ice.
Currently, Klages and his team are examining core sediments from the around 23 million-year-old Oligocene-Miocene epoch. The goal of their analysis is to improve climate change prediction models.

FAQs:

What did geologists discover in West Antarctica?
Geologists found an old river system buried beneath West Antarctica's massive ice sheet.

When did Earth experience major climate changes?
Earth's atmosphere changed significantly about 34-44 million years ago during the middle to late Eocene epoch.