Buried under the Antarctic ice cap of 3,500 kilometers, it was once a hidden landscape that once housed a flowing river. These ancient waterways of Aand now control how ice moves toward the ocean.
Scientists using radar measurements discovered the vast flat surface created by rivers about 80 million years ago, and then ice covered the continent.
This discovery reveals how geological processes from depth continue to shape modern ice dynamics, which have an impact on predicting future sea level rises. If completely melted, ice in eastern Antarctica is enough to increase global sea levels by 52 meters, thus understanding its behavior that is crucial to climate prediction.
Radar reveals hidden rivers
Researchers at Durham University examined radar data from multiple Antarctic surveys and found 31 different flat surfaces, accounting for 40% of the eastern coastline of Antarctica. These clearly preserved landscapes show the characteristic features of river erosion: slopes that sloping towards the coast, consistent elevations and patterns across the underlying rock structure.
“The landscape under the Antarctic ice sheet is not only one of the most mysterious ice sheets on Earth, but on any terrestrial planet in the solar system,” explained Dr. Guy Paxman, the study’s lead author and researcher at Durham University Royal University.
When the researchers adjusted the surface height to explain on ice, ancient riverbeds gathered at 200-450 meters at current sea level, where coastal plains formed in Antarctica’s ice-free past demarcated to the ocean level.
From Gondwana to Glacier
These river systems separated in eastern Antarctica and Australia about 80 million years ago, creating new levels of coastline and water flow base. Before the continent decomposition, the large rivers flowing from central Antarctica to northwestern Australia established a network of connected waterways throughout the ancient super-large Gondwana.
The surface of the newly mapped retains evidence of this transformation:
- timing: Formed between continental separation (about 80 million years ago) and ice cap formation (about 34 million years ago)
- scale: Each surface varies from 200 to 50,000 square kilometers
- save: Maintained a basic structure on ice for more than 30 million years
- Modern Influence: Flows ice directly into the deep channel while supporting the slow moving ice above
Ice road and speed limits
Today’s ice flow patterns follow this ancient template, precise. Fast moving glaciers, including major sockets such as Tott, Meuse and Denman, flow through deep grooves engraved between preserved rivers. Meanwhile, ice above a flat surface moves much slower, usually below 100 meters per year.
Professor Neil Ross of Newcastle University, a co-author of the study, points to the significance: “We have long been confused and confused about the fragments of evidence of the ‘flat’ landscape under the Antarctic ice sheet. This study fuses the data from the puzzle together to reveal the bigger picture.”
Ancient surfaces are natural obstacles to ice flow, which has the potential to regulate current ice flow rates. This suggests that even if climate change accelerates ice loss elsewhere, geological inheritance from the distant past may provide some stability to parts of the Eastern Antarctic.
Future ice behavior
Understanding these buried landscapes can improve predictions of eastern East Antarctica’s response to sustained warming. Flat surfaces can be used as a “fixed point” during stable ice retreats – ice remains rooted even if the surrounding area experiences sparseness.
As the ice edges retreat and thin, the surfaces of these elevated mounts may form ice, supporting inland ice cubes and slowly losing mass to the ocean. However, current ice sheet models may not be able to capture these effects completely, which may affect the accuracy of sea level predictions.
The research team stressed the need for direct sampling of these surfaces through ice drills to determine when they are free of ice. This information will help calibrate the model to act as the oceans and atmosphere continue to warm.
This discovery shows how deep history of the Earth continues to influence its current history, the rivers that cease to flow, millions of years ago, still shaped the movement of ice that could determine the future of human coastal areas. In the frozen archives in Antarctica, the past is still very active, i.e. what will happen next.
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