A cooperative U.S. and British mission in Antarctica recently discovered strange structures at the base of the Dotson Ice Shelf in West Antarctica.
The team discovered these structures using Ran, an autonomous underwater vehicle (AUV) that conducted 27 days of surveys along the glacier, covering more than 621 miles (1,000 kilometers). Ran discovered these structures in 2022, but the results were only recently published in scientific progress.
“We previously used satellite data and ice cores to see how ice shelves change over time,” Anna Wåhlin, an oceanographer at the University of Gothenburg and lead author of the paper, said in a press release from the British Antarctic Survey. “By navigating the submersible into the cavity, we are able to obtain high-resolution maps of the underside of the ice. It’s a bit like seeing the far side of the moon for the first time.
Lang’s subglacial mission has mapped the base of the ice shelf, helping researchers understand the nature of subglacial water flow and rapid melting of the ice shelf. It also shows that the base of the ice shelf has a “peak-and-valley icescape,” as the press release puts it, with plateaus and formations that resemble dunes, albeit made of ice. The team also found signs of high melt in vertical crevasses throughout the glacier.
As the team describes in their paper, existing models of the glacier’s undercarriage cannot explain the “mysterious teardrop-shaped indentations,” which they believe are caused by water flow. The team emphasizes that understanding these hitherto unknown processes is crucial to developing more accurate models that will better predict the melting of Antarctic ice.
“The map produced by Lan represents a huge advance in our understanding of Antarctica’s ice shelves,” Karen Alley, a glaciologist at the University of Manitoba and co-author of the study, said in the same press release . “We already knew how complex the ice shelf base was, but Lang found a broader and more complete picture than ever before.”
Unfortunately, given its premature demise, Ran probably should have been renamed “Run”. In January 2024, the team returned to the Dotson shelf to repeat the investigation. But after just one dive, Lan disappeared during his next routine run under the shelf. If the research team wants to continue their research, they will need to replace the submersible – which they certainly will.
“While we got back valuable data, we didn’t get everything we hoped for,” Walling said. “We hope to be able to replace Lang and continue this important work.”
