For decades, scientists have worked to predict how fast Antarctica’s ice is melting—and how much it will raise global sea levels. But a hidden influence beneath the ice could be speeding up the flow of ice into the ocean.

New research published in Nature Communications,
reveals that water flowing beneath the Antarctic Ice Sheet, known as subglacial
water, plays a much bigger role in ice loss than current models assume.

Streams of subglacial water in Antarctica come from melting at the base
where it grinds against the bedrock. The water acts to lubricate the flow of the
ice.

Computer models that are used to make projections
about the future behaviour of the Antarctic Ice Sheet don’t include the physical
processes controlling subglacial water, instead making assumptions about it’s
properties.

“By directly comparing these different
assumptions in one model, we found that projections can vary threefold. Our study
highlights how these assumptions about subglacial water — particularly near the ice
sheet margin where the grounded ice becomes floating — strongly influence sea-level
rise projections.”, says Rupert Gladstone who is one of
the authors of the article.

The first author of the recent
study Chen Zhao says that without a realistic
representation of the evolving properties of subglacial water, models may greatly
over or underestimate the risks of ice loss and the timing of tipping points —
critical thresholds where ice loss becomes unstoppable — by decades.

“As the world races to prepare for rising seas, integrating dynamic
subglacial water systems into ice sheet models is more critical than ever.”,
researchers conclude.

Open
access article Subglacial
water amplifies Antarctic contributions to sea-level rise in Nature
Communications 16, Article number: 3187 (2025).

More information:

Rupert Gladstone,
University Researcher
Arctic Centre at the University of Lapland
rupert.gladstone(@)ulapland.fi