Title: Ancient River Landscape Preserved Underneath East Antarctic Ice Sheet Could be Revealed by Global Warming
Date: October 24, 2023
According to a recent study published in Nature Communications, global warming could potentially unveil an ancient river landscape that has been hidden beneath the East Antarctic Ice Sheet for millions of years. While the landscape has not been exposed yet due to the massive ice retreat, projected climate warming could change that in the future.
Antarctica has been covered in ice for approximately 34 million years. Prior to that, the continent had a comparatively warm climate similar to the current Patagonia region in Argentina and Chile. Researchers have found evidence of tropical vegetation, including palm trees, in Antarctica during that time.
Scientists have recently discovered a large river-carved landscape in Antarctica, located in the Aurora-Schmidt basins inland of the Denman and Totten glaciers. This landscape existed between 34 million and 60 million years ago when other continents like Australia and India were separating from Antarctica. The ancient river would have flowed from the middle of the continent towards the coast.
Using satellites and ice-penetrating radar, researchers estimated that the landscape has been buried beneath the ice shelf for approximately 14 million to 34 million years. Prior to this technique, researchers mainly relied on flying planes equipped with radar to gather information about the topography under the ice sheet.
The landscape consists of three river-carved upland blocks separated by deep troughs, located only about 217 miles from the edge of the ice sheet. These blocks were formed prior to glaciation and represent a time when rivers crossed the region to a coastline that had formed during the breakup of the Gondwana supercontinent.
As Antarctica started to cool down, small glaciers formed in the river valleys. However, a significant cooling event occurred, causing the expansion of the East Antarctic Ice Sheet that covered the entire continent and buried the river landscape beneath it. This freezing effect preserved the landscape.
The study suggests that the ice over the region remained mostly stable for millions of years, despite intervening warm periods. Researchers aim to collect sediment and rock samples in the future to gain more insights into the vegetation and ecosystem that existed in the region when the river was active.
However, the study warns that climate warming could potentially result in ice retreat, exposing the ancient river landscape for the first time in at least 14 million years. While western Antarctica has experienced the most melting, with the “Doomsday Glacier” raising concerns over a 10-foot rise in sea levels, the ice shelf in east Antarctica holds the equivalent of 200 feet of sea level rise.
The study emphasizes the need to address global warming and implement ambitious mitigation efforts to prevent further ice melt in western Antarctica. Although it may be challenging to reverse the melting process in that region, researchers are hopeful that by studying the uncovered ancient landscape, they can gather crucial information about the continent’s past and its response to climate change.