Ancient Riverbeds Under Antarctica Shape Ice Loss
Hidden Landscapes Could Stabilize or Accelerate Melting
Vast, previously unknown flat surfaces buried deep beneath the East Antarctic Ice Sheet may play a critical role in how quickly this massive ice body responds to a warming climate.
Frozen Rivers Rediscovered
Researchers utilizing radio echo sounding have mapped a remarkable 2,100-mile-long network of flat terrain beneath the ice between Princess Elizabeth Land and George V Land. These plains, unrecorded until now, are believed to be the remnants of ancient river systems that shaped the bedrock eons ago.
The smooth surfaces likely formed after the East Antarctic tectonic plate broke away from the supercontinent Gondwana approximately 80 million years ago. This contrasts with rougher areas sculpted by glacial erosion over time.
Stabilizing or Destabilizing Forces
These ancient, coherent surfaces appear to have survived for over 30 million years, suggesting they offer a degree of stability to the overlying ice. In contrast, deeper troughs within the Antarctic landscape are more vulnerable to incursions of warmer ocean water, which can drive rapid ice melt.
Guy Paxman, lead author and Royal Society university research fellow at Durham University, noted that these newly discovered flat plains have “managed to survive relatively intact for over 30 million years.” He added that this preservation indicates certain parts of the ice sheet have maintained the original landscape rather than being eroded.
The findings suggest that while these ancient riverbeds might provide a stabilizing influence, the troughs are more likely to be hotspots for melting. This has significant implications for understanding future ice loss and its impact on global sea levels. For context, Antarctica has been losing ice at an accelerating rate, with recent estimates indicating an average of 150 billion tons per year between 2006 and 2015, contributing to sea-level rise (NASA Vital Signs).
Implications for Sea-Level Rise
The research highlights that a deeper understanding of the East Antarctic Ice Sheet’s geological history, including these buried features, is crucial. Such insights will be vital for refining predictions about future ice dynamics and their contribution to rising sea levels in our warming world.
