It was previously believed that a relatively flat and ancient craton—a stable piece of the lithosphere preserved since the time of the Gondwana supercontinent—lay beneath the thick ice of East Antarctica. A new study reported by Escape Velocity Space News paints a completely different picture: a complex fan-shaped landscape formed through rotational extension.
The June 24, 2026, article on cosmoquest.org draws on the work of an international team led by Egidio Armadillo, published in Nature Geoscience. Scientists combined data from radar sounding, gravimetry, seismic, and magnetic measurements, then applied computer models to understand how the terrain will "rebound" once the ice melts.
According to the source, the ice sheet reaches a thickness of 5 km at its deepest points and averages around 3 km. This massive weight is precisely what concealed the details of the continent's structure. While it was previously assumed that a "boring" craton lay beneath the ice, analysis revealed a fan-like basin structure created when a fragment of the Earth's crust rotated around a point and literally "fanned out."
Escape Velocity Space News emphasizes the practical significance of the discovery: the shape of the subglacial terrain directly influences glacial movement and the accuracy of melting forecasts. Incorporating these new details into models will allow for a better understanding of how sea levels will change in the future.
The source notes that understanding Earth's history is built upon studying modern landscapes and their movements. Where mountains are visible, tectonic plates have collided; where outlines and minerals match, continents have drifted apart. In Antarctica, however, researchers must rely on remote sensing, and the resulting picture is now significantly more complex than previously imagined.
According to the report, this discovery reshapes our view of the region's geological evolution and provides new directions for research. Further work will help clarify exactly how this fan-shaped landscape was formed and what processes continue beneath the ice today.
The study demonstrates that even the most hidden parts of the planet can harbor unexpected geological histories that must be accounted for when modeling climate and glacial processes.
