Deep ocean channels beneath Antarctica's floating ice shelves trap warm water and accelerate melting from below, threatening to raise sea levels faster than climate models currently predict, researchers report.
Scientists discovered that long channels carved into the underside of ice shelves act as conduits for warmer ocean water, dramatically increasing basal melting rates. These findings challenge previous assumptions about which regions remain stable. East Antarctica, long considered resistant to warming, now appears far more vulnerable to subsurface ocean heat than models suggest.
The research highlights a critical blind spot in current climate simulations. Existing models may not adequately account for how these channels funnel warm water toward ice shelf bottoms, creating localized hotspots of rapid melting. This process occurs hidden beneath hundreds of meters of ice, making it difficult to detect and monitor from the surface.
The discovery carries profound implications for sea level projections. If basal melting occurs at rates higher than predicted, Antarctica could contribute substantially more to ocean rise within this century. Coastal cities worldwide face greater flooding risks than previously estimated. The melting also triggers a cascade effect. As ice shelves thin from below, they lose structural integrity and flow faster into the ocean, accelerating glacier discharge inland.
Scientists used satellite observations, oceanographic data, and ice modeling to document these channels and their thermal effects. The work reveals that Antarctica's vulnerability extends beyond the West Antarctic Ice Sheet, which has dominated recent climate discussions. East Antarctic ice shelves, covering far vaster regions, may now require urgent monitoring.
Current uncertainties remain substantial. Researchers still need to quantify exactly how widespread these channels are and predict how ocean temperatures will evolve. Yet the core finding stands. Warm water reaches Antarctic ice shelves more effectively than models assumed, melting proceeds faster than anticipated, and global sea level rise projections require upward revision.
This research underscores why improving Antarctic monitoring matters for millions of people