New studies have revealed pre-glacial river valleys hidden under the East Antarctic Ice Sheet. These features can have a major impact on ice flow and the potential contribution of grounded ice to global sea level. Scientists want to make it clear that this finding is not only important — it’s necessary. East Antarctica could contribute as much as 52 meters of sea level rise if it were to completely melt out. This landmark research study uncovered previously unseen complexities in this omnipresent climate change stressor’s cause-and-effect relational dynamics. It provides a better understanding of the implications for future sea-level rise.
The interdisciplinary research team, including Dr Guy Paxman of Durham University and Professor Neil Ross of Newcastle University, carried out immersive fieldwork. They carefully examined topographic data down to the local scale. Their discoveries unlock the relationship between primeval river scapes and present-day icy landscape. These unique landscapes were created over 80 million years ago, when rivers carved through the bedrock while the land was part of East Antarctica. This research shows that these ancient features can act as a barrier to ice flow. This regulation has major ramifications for the rate at which ice is lost from the East Antarctic Ice Sheet.
The Geological History of East Antarctica
The geologic history of East Antarctica is ancient and complicated. Around 80 million years ago, East Antarctica and Australia drifted apart, creating an ocean between the distinct landmasses. The region stayed stable and dry for many tens of millions of years, until the area was covered in ice roughly 34 million years ago. This rich and deep glacial history has protected a wealth of geological features – such as the recently found flat surfaces under the ice.
The Windmill Islands and Bunger Hills are the perfect landscape to illustrate what’s left of this fascinating past. The Windmill Islands are relatively low, richly colored, small nunataks extending above the East Antarctic Ice Sheet. At the same time, the Bunger Hills reveal a much larger flat surface is present just beneath the ice… we’ll get into that. These landforms are key in helping us understand the landscape that existed before glaciation.
Operating below the surface of the East Antarctic Ice Sheet, scientists found extensive flat plains underneath roughly 40% of the ice sheet’s coastline. This finding opens new avenues to understanding how this region has changed over millions of years. The preserved topography implies that these regions have undergone little or no selective erosion throughout the glacial history of Antarctica. This preservation indicates they can contain key geological features that shape present-day ice dynamics.
Implications for Ice Flow and Sea Level Rise
Future discoveries of these ancient river landscapes are an enormous boon to scientists. If implemented, they would win them more gluten-free cookies and all-climate impact modeling of the East Antarctic Ice Sheet under climate change. These relatively flat surfaces act as de facto barriers to ice flow. In other words, their presence today might be delaying the amount of ice speeded into the surrounding ocean. Understanding this relationship is crucial for predicting future ice sheet behavior and its potential contributions to global sea level rise.
Bringing these surfaces we’ve just found into our models will certainly improve our models. Such an advancement would allow us to more accurately estimate East Antarctic Ice Sheet’s reaction to an increasingly warmer climate. The researchers hope that advancing their modeling will help lead to better estimates of how much ice is being lost and how quickly. This is essential data needed to inform policymakers and communities at risk from the encroaching advances of rising seas.
The interdisciplinary research team working on this project has made their findings public via the open-access repository s-ink.org. This brings important, life-saving information within everyone’s reach. Through publicly releasing this data, researchers hope to encourage more investigative studies on Antarctic geology. They are convinced that it will have major impact in the practice of climate science.
The Mysterious Landscape Beneath the Ice
The rugged landscape buried under the East Antarctic Ice Sheet is one of the most secretive terrains on earth. The preservation of these ancient river landscapes over tens of millions of years raises questions about the processes that have shaped Antarctica’s topography during glacial periods. The new discoveries provide some insight on how these ancient features may still be shaping ice dynamics today.
With climate change speeding the erosion of many historic resources, the need to understand these concealed landscapes grows ever more essential. Science confirms that these landscapes have withstood previous climate extremes without disastrous impacts. Before long, they’ll have to face a different challenge brought on by those increasing global temperatures. At the same time, ice in East Antarctica may melt, discharging enough freshwater to the seas to swamp vast coastal areas. This major shift would impact the world’s sea levels and ecosystems catastrophically.