Hidden beneath the ice of East Antarctica lies one of the continent's greatest mysteries and potentially one of its most significant climate threats. The Wilkes Subglacial Basin, a vast depression buried beneath kilometres of ice, remains among the least explored regions in Antarctica despite holding enough ice to raise global sea levels by an estimated three to four metres if widespread retreat were to occur.
A recent international review published in Nature Reviews Earth & Environment has drawn attention to the basin's importance, bringing together evidence from geology, oceanography, climate science and satellite observations. The paper, led by Australian researchers and involving scientists from 14 countries, highlights how little is known about the region and why understanding it is crucial for improving sea-level rise projections.
For many years, scientists considered East Antarctica relatively stable compared with the more vulnerable West Antarctic Ice Sheet. However, growing evidence suggests parts of the Wilkes Subglacial Basin may be more sensitive to warming than previously thought.
One area of concern is Cook Glacier, a major outlet glacier draining part of the basin into the ocean. Observations show the glacier has been thinning since the 1990s and now discharges around 40 billion tonnes of ice into the sea each year. Researchers believe warmer ocean water reaching the underside of coastal ice could eventually destabilise sections of the basin, accelerating ice loss.
The region's geological history offers further clues. Evidence suggests the basin experienced significant retreat during the Pliocene, around three million years ago, when atmospheric carbon dioxide concentrations were comparable to, or lower than, those seen today. While past climate conditions cannot be directly compared with the modern world, they indicate that large-scale change is possible under sustained warming.
Despite its importance, the Wilkes Subglacial Basin remains remarkably difficult to study. Vast distances, severe weather and challenging sea-ice conditions have limited exploration, leaving major gaps in scientists' understanding of the seabed, ocean conditions and the processes taking place beneath the ice sheet.
The recent review does not claim that major ice-sheet collapse is imminent. Instead, it underscores how little is known about a region that could profoundly influence future coastlines. As scientists work to unlock the secrets of this remote Antarctic basin, the Wilkes Subglacial Basin is increasingly being viewed as a sleeping giant whose future behaviour may have global consequences.