“Antarctic bedrock is mostly obscured by the Antarctic Ice Sheet, which covers more than 99 % of the continent,”stated very first author University of Genoa’s Dr. Egidio Armadillo and coworkers.

“Recently, worldwide collections of radio-echo sounding information have actually fixed massive subglacial topographic functions in increasing information, exposing a broad and low-elevation sector of East Antarctica extending from Prydz Bay to the Transantarctic Mountains and from the coast inland to 85 ° S.”

“In this area, the majority of the big subglacial basins are V-shaped and lined up along the north-south instructions.”

“Moreover, the 2,000-km-long Antarctic shoreline and continent-ocean border margin, delimiting the sector to the north, has an unique semi-circular arc geometry.”

“At a semi-continental scale, the topography looks like a portable fan, assembling to a point situated near to the South Pole.”

“We propose that the whole area is a single physiographic system and name it the East Antarctic Fan-Shaped Basin Province (EAFBP).”

The EAFBP structure consists of a few of Antarctica’s best-known subglacial functions, such as the Wilkes and Aurora basins and the basin hosting Lake Vostok, the biggest recognized subglacial lake in the world.

Analysis recommends the structure was formed by a procedure referred to as dispersed rotational extension.

This is where the continental crust has actually expanded from a main point.

The pattern resembles a hand, with the base of the thumb as the set point, and fingers expanding revealing the extending.

The spaces in between the fingers resemble the triangular basins that form as it opens.

According to the researchers, EAFBP might be among the biggest examples of rotational extension ever seen in continental crust.

It might have established through several tectonic stages connected to the development of the supercontinent Gondwana and the later separation in between Antarctica and Australia and might even have actually affected this separation.

The discovery likewise raises fresh concerns– especially around the accurate age of the structure and the geodynamic systems that produced it.

The significance of the discovery extends beyond historic insight.

“The shape of the bedrock concealed below the ice sheet continues to affect ice circulation today, managing the circulation of subglacial basins and lakes,” the authors stated.

“This might possibly impact the stability of parts of the Antarctic Ice Sheet that are especially conscious environment modification.”

The research study was released June 3 in the journal Nature Geoscience

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E. Armadillo et alA fan-shaped subglacial basin province in East Antarctica formed by rotational extension. Nat. Geoscireleased online June 3, 2026; doi: 10.1038/ s41561-026-01991-6