Huge Ancient River Discovered Under Antarctica’s Ice


Picture this: Antarctica, not as a frozen wasteland, but as a verdant land with sprawling rivers and lush forests.

It’s hard to believe, but during the mid-late Eocene epoch, about 44-34 million years ago, large parts of Antarctica were ice-free.

This was a time when our planet was much warmer, and Antarctica enjoyed regular rainfall, fostering thriving forests and, of course, rivers.

A Journey Through Time

Recently, an astonishing discovery has been made, revealing the existence of a giant ancient river system that once meandered through this now icy continent.

This revelation came from the depths of the Amundsen Sea, where a team of researchers, led by Professor Cornelia Spiegel from the University of Bremen, drilled into the sediment using the mighty icebreaker Polarstern.

They unearthed 17-24 meters (56-79 feet) of sediment, rich in minerals that were a mismatch for the nearby West Antarctica. Instead, these minerals hailed from the Transantarctic Mountains, a colossal range that slices through the heart of the continent.

This finding suggests a massive river, over 1,500 kilometers (932 miles) long, once flowed from these mountains to the Amundsen Sea.

The Mighty River of the Past

Now, a river of such length might not be particularly extraordinary today, but back then, it would have been the titan of West Antarctica.

Imagine a river that dominated the landscape, carving its way through the continent, feeding a swampy delta comparable to the modern Rhine or Rio Grande.

The Transantarctic Mountains, always diligent in their duty, funneled precipitation away through glaciers and rivers.

But instead of taking the shortest route to the sea, this ancient river embarked on a grand journey across the continent.

This path hints that West Antarctica must have been significantly higher than today, forming vast, flat coastal plains above sea level.

The Icy Shift

Fast forward to about 34 million years ago, and the picture changes dramatically.

The advent of permanent glaciation and possible seaway developments closer to the mountains likely marked the end of this majestic river’s reign.

Spiegel and her team propose that a series of geological events, including sediment deposition, rift-related magmatism, seafloor spreading, and the rise of the Transantarctic Mountains, all kicked off around 44-40 million years ago, ending around 34 million years ago with the icy grip of glaciation.

Looking to the Future

While we can’t expect this ancient river to make a comeback, especially with the ongoing changes to our climate, understanding its existence offers us a crucial glimpse into our planet’s past.

This knowledge helps us comprehend the dramatic transformations that led to the icy world we see today and could inform our understanding of future changes.

So, the next time you think of Antarctica, remember it wasn’t always a land of ice.

Once, it boasted mighty rivers and lush forests, painting a very different picture of our planet’s southernmost continent.