Scientists Looked Beneath Antarctica’s Sea Ice — and Found a Strange Upside-Down World

If all the water of Thwaites Glacier melted, it would flood the entire West Antarctica valley, likely spilling into the eastern side and causing the blue-colored polar south point on the globe to turn into an amoebic, dilated pupil. Climate change is already threatening to push this glacier into total melt mode. In 2022, Ran, an orange-colored, torpedo-shaped unmanned submersible, plunged into the depths of sea ice to explore the underside of the Dotson Ice Shelf, located near Thwaites. In a new study published in the journal Science Advances, they documented the fascination they felt after noting surreal, cryptic patterns emerging from the layers of liquid ice.

Ran, this underwater vehicle, traversed about 621 miles for the next 27 days, barrelling on the rising swells and clinging to the understory currents. The 20-foot submersible was arranged by the International Thwaites Glacier Collaboration (ITGC) along with scientists from the University of Gothenburg, Sweden. Back in the laboratory, Anna Wåhlin, oceanographer and lead researcher, was immersed in studying the data that Ran was sending as she investigated the glacial waters.

The upside-down icescape looked like the “dark side of the moon,” as Wahlin described. The icescape was blanketed with mysterious “swirls and scoops” never seen before. “We were very nervous,” Wahlin recalled of the time when Ran was sent below to explore the sea ice. There were two objectives of the project: one, to figure out the mechanism of how glaciers melt faster with newer, stronger undercurrents, and second, to catch glimpses of the topography of this ice-shelf. The images they received resembled “works of art,” including plateaus, canyons, and teardrop-shaped formations, according to the team's descriptions.

An ice shelf is basically a buttress that keeps the ice from flowing into the ocean and guards the sea levels from rising, as the BBC explains. Ran, she said, also had a “pulsed sound wave” detection program embedded into it that would enable it to record the soundscapes creeping underneath. Ran’s investigation revealed a lot of things apart from the unusual topographic formations. For instance, it sent back data that provided amazing insights into the behavior of the West Antarctic Ice Sheet (WAIS), an area of ice of the same size as India. The eastern ice shelf was much thicker than the western shelf, which implied it was melting slower than the one in the west.

The phenomenon they described behind these intersecting water currents was “Circumpolar Deep Water (mCDW),” in which the waters of the Pacific and Indian oceans blend, a process that impacts the ice base. “The mapping has given us a lot of new data that we need to look at more closely,” Wåhlin said in a press release. “With this method, we have a better chance of finding the answers.”

After the 2022 episode, Ran was sent again into the depths of Antarctic sea ice in 2024, but this dive left the scientists above alarmed and concerned. This time, after Ran plunged into the sea ice, it vanished. Scientists were left puzzling over all the possibilities that could have swallowed up the submersible. Maybe it went too deep aground; maybe it became a victim of a curious, hungry seal. The cause remained a mystery, but thanks to the sophisticated technology, Wahlin received some valuable data.