A network of V-shaped subglacial basins stretching across East Antarctica, arranged in a pattern that resembles a giant hand radiating from a focal point near the South Pole, has been mapped for the first time in a peer-reviewed study published in Nature Geoscience. The structure formed through distributed intraplate rotational extension during the breakup of the ancient supercontinent Gondwana, and its geometry may influence how the East Antarctic Ice Sheet responds to warming over the coming centuries.
How buried basins beneath East Antarctica could reshape ice-loss forecasts
The discovery matters because East Antarctica holds enough ice to raise global sea levels by tens of meters, yet the bedrock beneath it has long been treated as a relatively stable, poorly understood platform. The newly identified fan-shaped province changes that picture. Its semi-continental-scale pattern of V-shaped basins radiates outward from a single focal point near the South Pole, meaning the crustal weaknesses are not scattered randomly but follow a coherent geometry tied to ancient plate rotation.
That geometry has practical consequences. Radial lineaments running through the basin province could create localized zones where basal friction between ice and bedrock is lower. If future warming reduces effective ice thickness by several hundred meters in those corridors, the structural grain of the rock beneath could channel faster ice flow and accelerate the onset of new ice streams. No ice-sheet model currently accounts for this kind of directional bedrock control at such a large scale, which means projections of East Antarctic ice loss may be underestimating the role of geology in steering future change.
Earlier work had already established that East Antarctica is not the monolithic craton scientists once assumed. A roughly 2,500-km rift system surrounding the Gamburtsev Mountains, along with a thick crustal root beneath the range, showed that rifting triggered mountain uplift deep inside the continent. The new fan-shaped basin province extends that picture by connecting disparate rift features into a single rotational framework anchored at the pole.
Airborne surveys and plate-kinematic data that revealed the fan
The study draws on airborne gravity, magnetic, and radar datasets collected during campaigns such as AGAP-GAMBIT, which surveyed the buried terrain above and around the Gamburtsev Mountains. Flight-line data from the Polar Airborne Geophysics Data Portal, curated by the British Antarctic Survey, supplied additional observations that helped resolve the shape and extent of individual basins within the fan.
To interpret the geometry, the researchers compared the inferred pivot point of the basin province against established Euler poles for Cenozoic motion between East and West Antarctica. That earlier plate-kinematic study provided quantified rotation parameters and a vetted chronology, giving the team an independent check on whether the fan’s focal point is consistent with known extension history. The match supports the conclusion that distributed rotational extension, rather than a single discrete rift, shaped the interior of the continent as Gondwana broke apart.
Isostatic rebound calculations also played a role. The study used an elastic-plate approach to compute how the bedrock surface would change if the modern ice load were completely removed. That method, documented in a separate peer-reviewed analysis of total unloading scenarios for both Greenland and Antarctica, allowed the authors to reconstruct a “rebounded” bed topography and confirm that the V-shaped basin pattern persists regardless of whether the ice is present or absent. The structural signal, in other words, is real geology, not an artifact of ice-loading distortion.
Open questions about the fan’s role in future ice dynamics
Several gaps remain. No direct, attributable quotes from the lead authors have been published outside of the peer-reviewed paper itself, limiting the ability to gauge how strongly the research team endorses specific ice-dynamic implications versus treating them as hypotheses for future testing. The exact flight-line segments that image the central “palm” region of the fan have not been specified in publicly available methods sections, making independent replication harder for outside groups.
The quantitative rotation parameters from the earlier Cenozoic motion study are cited but not re-derived or tabulated side by side with the new Euler-pole comparison in the 2026 article. That leaves a gap for readers trying to judge how tightly the geometry is constrained. Similarly, while the isostatic-rebound framework is well established, the study does not report site-specific rebound values for individual basins within the fan province, so the magnitude of bedrock uplift in each corridor remains an open variable.
The most consequential unknown is whether the radial lineaments actually reduce basal friction enough to steer ice flow at the scale the geometry suggests. Testing that hypothesis will require coupling the new structural map with ice-sheet models that can resolve basal conditions at high spatial resolution. Until those simulations are run, the fan-shaped province stands as a newly recognized piece of Antarctic geology whose influence on ice stability is plausible but unquantified. The next development to watch is whether modeling groups incorporate the basin geometry into their projections for East Antarctic ice loss during the current assessment cycle.
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*This article was researched with the help of AI, with human editors creating the final content.
