Underwater Ocean Storms Accelerate Melting of Antarctica's Most Dangerous Glacier

Hidden Ocean Turbulence Threatens Global Coastlines

Deep beneath Antarctica's ice, invisible storms are quietly rewriting the future of global sea levels. Swirling underwater eddies are aggressively melting two Antarctic glaciers, including one that could raise sea levels by multiple feet, according to a recent study that reveals potentially "far-reaching implications" for global sea level rise. These aren't ordinary ocean currents—they're fast-moving, chaotic underwater weather systems that scientists are only now beginning to understand.

Thwaites Glacier, known as the Doomsday Glacier because of the devastating impact its demise would have on global sea level rise, sits alongside Pine Island Glacier in West Antarctica. Thwaites alone holds enough water to raise sea levels by more than 2 feet, but because it acts as a cork holding back the vast Antarctic ice sheet, its collapse could ultimately lead to around 10 feet of sea level rise. That's enough to permanently flood coastal cities from Miami to Mumbai.

The Science Behind the Underwater Chaos

The new study, published last month in Nature Geosciences, is the first to systematically analyze how the ocean is melting ice shelves over just hours and days, rather than seasons or years. Over the past few decades, these icy giants have experienced rapid melting driven by warming ocean water, especially at the point where they rise from the seabed and come afloat as ice shelves.

The eddies spin up in the open ocean and race underneath ice shelves. Sandwiched between the complex, rough base of the ice shelf and the seafloor, the eddies churn up warmer water from deeper in the ocean, which enhances melting when it "hits" vulnerable ice. Together with other short-lived processes, the storms caused 20% of the melting at the two glaciers over a nine-month period.

A Dangerous Feedback Loop

What makes these underwater storms particularly concerning is their self-reinforcing nature. As the storms melt the ice, they increase the amount of cold, fresh water entering the ocean, which mixes with warmer, saltier water beneath, generating more ocean turbulence, which in turn increases ice melting. "This positive feedback loop could gain intensity in a warming climate," said study author Lia Siegelman of UC San Diego's Scripps Institution of Oceanography.

The consequences could be grave as the ice shelves play a vital role holding back the glaciers, slowing their flow into the ocean. Think of these ice shelves as natural dams—once they're gone, there's nothing stopping the massive glaciers behind them from sliding into the sea at an accelerated pace.

Uncertain Science, Certain Stakes

There are still huge uncertainties, as Antarctic ice shelves are among the least accessible places on Earth, meaning scientists have to rely heavily on simulations. "These kinds of studies are intriguing but they are computer models," said David Holland, a professor of mathematics and atmosphere and ocean science at NYU. The remoteness of Antarctica makes direct observation incredibly challenging and expensive.

Yet the implications are too significant to ignore. "Hundreds of things are of similar importance to the decay of the ice sheet," said Ted Scambos, senior research scientist for the Earth Science and Observation Center at the University of Colorado Boulder. "Awareness of the dynamics of the near-ice-sheet ocean is evolving rapidly." As climate models become more sophisticated, scientists are discovering that the forces threatening Antarctica's stability are more complex and numerous than previously understood—making accurate predictions both more difficult and more urgent than ever.