Researchers found long channels beneath the Fimbulisen Ice Shelf in East Antarctica can trap relatively warm seawater, sharply accelerating melt from below in areas once considered comparatively stable.
Modeling and field data showed melt rates inside some channels can jump by roughly an order of magnitude because small circulation cells keep heat pressed against the ice instead of flushing it away.
That concentrated melting can deepen and widen the channels, unevenly thinning the shelf and weakening its ability to hold back inland glaciers that would otherwise flow faster into the ocean.
Scientists said current climate models do not capture this process, raising the risk that projections for East Antarctic ice loss and global sea level rise are too low.
The Nature Communications study adds to a major IPCC uncertainty over polar ice shelves and could affect coastal planning, Southern Ocean circulation and nearby marine ecosystems.
Hidden channels are melting Antarctica from below. Are our climate models leading us towards an unseen coastal catastrophe?
If even 'stable' East Antarctica is rapidly melting, is any part of the continent truly safe from collapse?
Discovery of Sub-Ice Channels in Antarctica Reveals Underestimated Risk of Rapid Sea Level Rise
Overview
In May 2026, scientists made a major discovery: channels beneath Antarctic ice shelves trap warm ocean water, causing it to circulate in confined spaces and stay in contact with the ice for longer periods. This process greatly speeds up melting from below, especially in East Antarctica’s 'cold' ice shelves, which are more sensitive to small temperature increases than previously thought. Current climate models do not fully account for this accelerated melting, meaning they may underestimate future sea-level rise. This breakthrough highlights the urgent need to improve models and monitoring to better predict and respond to global climate risks.