A groundbreaking study published in Nature Geoscience has revealed a previously unknown topography beneath the East Antarctic Ice Sheet, potentially offering new insights into the region’s ice flow and its impact on global sea level rise. The research, conducted by a team led by Durham University, utilized radar technology to map vast, flat surfaces beneath the ice, which were once shaped by rivers before Antarctica became covered in ice millions of years ago. These findings, detailed in the study, could help refine projections about how the East Antarctic Ice Sheet will respond to future climate change, a crucial factor in predicting the future of global sea levels.
Ancient River Landscapes Beneath East Antarctica
The newly discovered river landscapes beneath the East Antarctic Ice Sheet span approximately 3,500 kilometers along the coastline between Princess Elizabeth Land and George V Land. These flat surfaces, now hidden beneath layers of ice, are remnants of ancient river systems that existed when East Antarctica and Australia separated roughly 80 million years ago. It is believed that these landscapes were formed before the onset of ice coverage in Antarctica about 34 million years ago.
Dr. Guy Paxman, the research lead and a Royal Society University Research Fellow at Durham University, emphasized the exceptional preservation of these ancient surfaces. He noted, “The landscape hidden beneath the East Antarctic Ice Sheet is one of the most mysterious not just on Earth, but on any terrestrial planet in the solar system.” He went on to explain that the team had been examining radar images of the sub-ice topography, revealing remarkably flat surfaces that had been preserved for over 30 million years. These surfaces, seemingly intact despite millions of years of ice coverage, are crucial to understanding the dynamics of ice flow in East Antarctica.
The topography beneath the Antarctic Ice Sheet (graphics available via the open-access s-ink.org repository). Credit: Open-access s-ink.org repository
The Role of Flat Surfaces in Ice Flow Dynamics
These ancient river landscapes, now buried beneath thick ice, play a pivotal role in moderating the movement of glaciers. The flat surfaces act as barriers, controlling the flow of ice, particularly in regions where deep troughs allow fast-flowing glaciers to navigate. Dr. Paxman further elaborated, “The flat surfaces we have found have managed to survive relatively intact for over 30 million years, indicating that parts of the ice sheet have preserved rather than eroded the landscape.”
This discovery sheds new light on the complex interactions between ancient landscapes and modern ice flows. The presence of these flat surfaces beneath the ice sheet could significantly influence how glaciers behave today, potentially slowing their movement and impacting the rate of ice loss. The findings suggest that these surfaces may currently be playing a role in regulating the flow of ice from East Antarctica, a region that holds the potential to raise global sea levels by 52 meters if it were to melt completely.
Implications for Predicting Future Ice Loss
The discovery of these ancient landscapes provides a crucial piece of the puzzle in understanding how East Antarctica’s ice sheet may react to future warming. The flat surfaces may influence the rate at which ice flows, and by incorporating this factor into climate models, scientists can better predict how the ice sheet will behave under various warming scenarios. This understanding is essential for refining projections of sea-level rise, particularly as global temperatures continue to increase.
Professor Neil Ross, a co-author of the study and Professor of Polar Science and Environmental Geophysics at Newcastle University, shared his thoughts on the significance of the findings: “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’s findings also underline the necessity for further research into how these ancient surfaces may have influenced ice flow during past periods of warmer climates. Such studies would not only help scientists understand how East Antarctica’s ice sheet could react to future climate warming, but also improve predictions of its potential impact on global sea levels.