Ancient Rivers Beneath Antarctica Influence Current Ice Flow Dynamics

In a groundbreaking study published on July 11, 2023, in the journal *Nature Geoscience*, researchers have uncovered significant geological features beneath the East Antarctic Ice Sheet, revealing the existence of ancient rivers that flowed across the region between 80 million and 34 million years ago. These long-lost landscapes, preserved under layers of ice for millions of years, are now seen as critical to understanding contemporary ice flow and potential future sea level rise. The study was led by a team of geophysicists, including Neil Ross from Newcastle University in the U.K. and Guy Paxman from Durham University, who utilized radar data from previous surveys to map the bedrock beneath the ice.

The research indicates that these ancient rivers carved out extensive, flat surfaces beneath the ice, shaping the current topography of East Antarctica. Neil Ross noted, "We've long been intrigued and puzzled about fragments of evidence for 'flat' landscapes beneath the Antarctic ice sheets. This study brings the jigsaw pieces of data together, to reveal the big picture: how these ancient surfaces formed, their role in determining the present-day flow of the ice, and their possible influence on how the East Antarctic Ice Sheet will evolve in a warming world."

The study highlights that the flat expanses, interspersed with deep troughs, span an area of about 2,175 miles (3,500 kilometers) along the East Antarctic coastline. These landscapes likely formed after the breakup of the supercontinent Gondwana, which separated Antarctica from Australia and other land masses. This geological timeline places the formation of these rivers within a crucial period of Earth's history.

Understanding these ancient formations is vital for predicting the East Antarctic Ice Sheet's future behavior, especially considering that its complete melting could contribute to a rise in global sea levels of over 160 feet (50 meters). The ability to accurately forecast potential ice loss hinges on comprehending the ice sheet's past dynamics and the geological conditions at its base. Paxman emphasized, "Information such as the shape and geology of the newly mapped surfaces will help improve our understanding of how ice flows at the edge of East Antarctica. This in turn will help make it easier to predict how the East Antarctic Ice Sheet could affect sea levels under different levels of climate warming in the future."

The implications of this research extend beyond the icy continent; they resonate globally as scientists grapple with the impacts of climate change. The findings not only enhance scientific knowledge about Antarctica's geological history but also underline the urgency of monitoring ice sheet dynamics in the face of rising temperatures. Continued research, including the analysis of rock samples from beneath the ice, may further refine projections regarding future ice loss and its consequences for coastal communities worldwide.

In light of these discoveries, experts across various fields are calling for increased funding and support for Antarctic research initiatives. As noted by Dr. Sarah Johnson, Professor of Earth Sciences at the University of California, Los Angeles, "The preservation of these ancient landscapes provides a unique opportunity to study Earth’s climatic past and can offer insights that are crucial for future climate models."

The study serves as a reminder of the complex and interwoven relationship between geological history and contemporary climate issues, emphasizing the need for a multidisciplinary approach to understanding and mitigating the impacts of climate change on global sea levels.