Underwater ‘Storms’ Are Eating the Doomsday Glacier — Short‑Lived Eddies May Accelerate Sea‑Level Rise

Swirling, short-lived underwater “storms” — called submesoscale eddies — are intensifying melting beneath the floating ice shelves of Pine Island and Thwaites glaciers, new research shows. The finding raises fresh concerns about how quickly Antarctic ice could contribute to global sea‑level rise.

What The Study Found

The study, published in Nature Geosciences, is the first systematic look at how ocean processes operating on hours-to-days timescales — rather than months or years — affect ice-shelf melt. Combining computer models with in‑situ ocean measurements, the authors report that short‑lived, weather‑like ocean features were responsible for roughly 20% of the melt observed at the two glaciers during a nine‑month period.

How These “Underwater Storms” Work

Submesoscale eddies are fast-changing swirls of water that form where warm and cold water masses meet. In the open ocean they can stretch up to about 6 miles across. Once generated, these eddies can rush beneath ice shelves and, trapped between an uneven ice base and the seafloor, stir warmer deep water upward. That warm water accelerates melting where it contacts vulnerable ice.

Icebergs detach from the Pine Island Glacier in Antarctica, one of the continent's fastest-retreating glaciers, February 11, 2020. - Lauren Dauphin/NASA Earth Observatory/Reuters

“We are looking at the ocean on very short ‘weather‑like’ timescales, which is unusual for Antarctic studies,” said Yoshihiro Nakayama, a co-author and assistant professor at Dartmouth College.

Worrying Feedbacks

The researchers describe a positive feedback: meltwater from the ice shelves freshens and cools the upper ocean, which then mixes with warmer, saltier water beneath and generates more turbulence — driving yet more melting. Co-author Lia Siegelman of Scripps Institution of Oceanography warns this loop could strengthen in a warming climate.

The Stakes

Ice shelves act as a buttress that slows the flow of inland ice into the sea. Thwaites Glacier alone contains enough ice to raise global sea levels by more than 2 feet. If Thwaites’ ice‑shelf support fails and triggers broader instability in the West Antarctic Ice Sheet, long‑term sea‑level rise on the order of ~10 feet is a conceivable, though longer‑term, risk.

Uncertainties And Next Steps

Scientists not involved in the study welcomed the new perspective but urged caution. Antarctic ice‑shelf environments are extremely difficult to observe, so models play a large role in current results. As NYU’s David Holland noted, more direct, real‑world measurements are essential to verify the models and better quantify how common and powerful these eddies are over seasons and years.

Why This Matters: The study highlights that ocean “weather” on short timescales matters for ice loss. Improving observations of fine‑scale ocean dynamics beneath ice shelves is now a critical frontier for predicting future sea‑level rise.