Hidden Basin Network Discovered Beneath East Antarctic Ice Sheet
Scientists have identified a massive, fan-shaped network of subglacial basins beneath East Antarctica, linking well-known features like the Wilkes and Aurora basins and Lake Vostok into a single geological province. Named the East Antarctic Fan-shaped Basin Province, the structure likely formed through ancient rotational extension of the continental crust. The discovery, published in Nature Geoscience by an international team led by the University of Genoa and including Durham University, provides new insights into Antarctica's tectonic history and may help researchers understand how the ice sheet behaves today, including its stability in a warming climate.
Scientists have uncovered a vast, hidden geological structure beneath the East Antarctic Ice Sheet, linking several well-known subglacial features into a single, interconnected province. The finding, published in Nature Geoscience by an international research team led by the University of Genoa and including Durham University, reveals a continent-scale fan-shaped network of basins concealed under more than three kilometers of ice in some places. This structure, named the East Antarctic Fan-shaped Basin Province (EAFBP), encompasses the Wilkes and Aurora basins as well as the basin containing Lake Vostok, the largest known subglacial lake on Earth. Although these features have been studied individually for years, they are now recognized as parts of one massive geological system.
The structure is believed to have formed through a process called distributed rotational extension, where continental crust gradually stretched outward from a central point. Researchers compare the pattern to a hand, with the base of the thumb remaining fixed while the fingers spread apart. The spaces between the fingers resemble the triangular basins created as the crust extended. This feature may represent one of the largest examples of rotational extension ever identified within continental crust, potentially linked to the formation and evolution of the ancient Gondwana supercontinent and the later separation of Antarctica and Australia.
The discovery has important implications for understanding modern ice sheet dynamics. The shape of the bedrock beneath the ice influences how ice moves across the continent, helping determine the location of subglacial basins and lakes. This hidden landscape may affect the stability of regions of the Antarctic Ice Sheet that are particularly vulnerable to climate change. To investigate the structure, researchers combined multiple data sources, including subglacial topography, geological observations, gravity measurements, magnetic data, seismic information, and models of the crust and lithosphere. Dr. Guy Paxman, from the Department of Geography at Durham University, led calculations estimating how East Antarctica's landscape would appear if the entire ice sheet were removed, revealing a "rebounded topography" that allowed scientists to examine the elevation and orientation of the newly identified geological province.
