Researchers report an Antarctica Hidden Geological Feature beneath the East Antarctic Ice Sheet that links several enormous subglacial basins into one fan shaped system, the East Antarctic Fan-shaped Basin Province, according to an international research team.
The province groups well known basins, including the Wilkes Basin, the Aurora Basin, and the basin that contains Lake Vostok, the largest known subglacial lake on Earth, as described in the study.
Scientists say the basins form a continent scale fan shaped pattern and occur beneath ice thicker than three kilometres in some places, creating an extensive hidden landscape that had been studied only in parts until now.
The research team characterises the feature as the surface expression of deep tectonic processes and identifies distributed rotational extension as the likely mechanism for its formation, a process compared to a hand with spreading fingers.
Methods And Implications For Ice And Geology
To reveal the province, researchers combined subglacial topography, geological observations, gravity and magnetic measurements, seismic information, and crust and lithosphere models, the paper reports.
Dr Guy Paxman of the Department of Geography led calculations to model rebounded topography, estimating the land could rise by as much as one kilometre if the ice were removed, the team says.
The study was led by Dr Egidio Armadillo of the University of Genoa and received support from the Italian National Antarctic Research Program, and the author list includes scientists from the University of Cambridge Department of Geography.
Researchers note the fan shaped province may represent one of the largest examples of rotational extension identified in continental crust and that it likely formed during multiple tectonic episodes tied to Gondwana's evolution.
The team also suggests the structure may relate to the later separation of Antarctica and Australia and could have influenced that continental breakup, though the timing and detailed geodynamics remain open questions.
Beyond reconstructing ancient geology, the finding matters for present day ice dynamics because bedrock shape controls ice flow, subglacial basins, and lake locations, so the hidden landscape may affect ice sheet stability in vulnerable regions.
The authors published their analysis in Nature Geoscience and provide a detailed structural frame, noting this is the first time the linked basins have been recognised as parts of a single, interconnected province.
