Radar mapping reveals 30-million-year-old landscapes beneath Antarctic ice

A team of British scientists has uncovered a vast, ancient river landscape hidden beneath the East Antarctic Ice Sheet, shedding new light on how the continent’s ice may respond to future climate change. The discovery, published in Nature Geoscience, reveals a remarkably preserved topography that predates the continent's icy cover by millions of years — a find that could help refine global sea-level rise forecasts.

Led by researchers from Durham University, the study used advanced radar imaging to map a 3,500-kilometre stretch of buried terrain along the coastline between Princess Elizabeth Land and George V Land. The terrain consists of expansive flat surfaces shaped by rivers long before Antarctica froze over around 34 million years ago. Scientists believe these features were formed during the ancient breakup of East Antarctica and Australia roughly 80 million years ago.

Dr. Guy Paxman, the lead author and a Royal Society University Research Fellow at Durham, described the discovery as “one of the most mysterious not just on Earth, but on any terrestrial planet in the solar system.” He noted that the preservation of these flat surfaces for over 30 million years suggests the ice sheet has largely protected — rather than eroded — the underlying terrain.

The significance of this lies in how the landscape affects the flow of ice. These ancient riverbeds, now buried beneath kilometres of glacial ice, appear to act as stabilising structures. Their flatness moderates the movement of ice, particularly near deep troughs where glaciers tend to flow more rapidly. As a result, they could be slowing down the rate of ice loss in certain regions of East Antarctica — a crucial insight, given that the complete melting of the ice sheet could raise global sea levels by as much as 52 metres.

Professor Neil Ross of Newcastle University, a co-author of the study, said the findings help resolve long-standing questions about scattered evidence of flat terrain under the ice. “This study brings the jigsaw pieces of data together to reveal the big picture,” he said, highlighting the implications for understanding ice dynamics both past and future.

The research adds a vital new dimension to climate modelling. As global temperatures continue to rise, understanding how subglacial landscapes influence ice flow will be essential to predicting the pace and extent of Antarctic ice loss. The team hopes further studies will explore how these ancient surfaces affected ice behaviour during previous warm periods — a key to unlocking the future of sea-level change.

By Vugar Khalilov