Scientists have discovered three channels of warm water under Antarctica’s Thwaites Glacier mixing underneath the ice, threatening the glacier’s collapse. “Thwaites has got these three guns pointed right at it,” Erin Pettit, a glaciologist at Oregon State University in Corvallis, told Nature. “There is warm water coming from all directions.”
Pettit, who is co-leader of a five-year project investigating Thwaites’ stability, presented the team’s initial findings at the American Geophysical Union’s ocean science meeting, held in San Diego, California, earlier this week, the magazine reports.
Data gathered during the first two years of the project has heightened concerns the glacier could collapse. If this happens it could raise global sea levels by two feet. That is enough to cause “significant problems” for coastal cities, according to NASA.
There is also a concern that if the glacier collapses, it could trigger others to do the same. If this happens, Thwaites could be the largest single driver of sea level rise in the 21st century, say scientists.
Pettit and her team’s research on Thwaites is part of a larger mission coordinated by the International Thwaites Glacier Collaboration. Data collected over the course of the program will eventually be fed into modeling systems.
According to Nature, the expedition completed last year was the first to reach the tip of the Thwaites ice shelf, the section of the glacier straddles the ocean, and is typically sealed in by sea ice.
Pettit’s team deployed an underwater robot named Rán, after the Norse goddess of the sea. It obtained data on ocean conditions underneath the shelf, plus information that has since informed detailed seafloor maps of the area.
Information collected over the last two years suggests warm water is hitting Thwaites from Pine Island Glacier to its north. This warm water is merging with two more streams of warm water coming from different directions underneath the ice shelf, Nature reports.
The warm water streams threaten to destabilize Thwaites’ traditionally more stable eastern side—which flows at approximately 2,000 feet per year, compared to 1.2 miles per year on the western side.
One of the most surprising finds to come out of the project, said Pettit, is the discovery that the Thwaites glacier contains a rich and complex landscape of channels, ridges and cliffs on its underside, forged by warm water currents, showing that the glacier is not melting uniformly.
Pettit and her team are just two years into a five-year mission. At the end, scientists expect to know more about the risks and vulnerabilities of the Thwaites glacier and its future. “We’ve never seen an ice sheet disintegrate in a warming climate, so we’re struggling to project how it could happen,” Ted Scambos, a glaciologist at the National Snow and Ice Data Center in Boulder, Colorado, told Nature.