A team of scientists concluded that the rapid retreat of the Thwaites Glacier in West Antarctica was due to different processes below the floating ice shelf than researchers had previously thought. His estimate is based on new observations from where the ice enters the ocean. They show that while melting under most of the ice shelf is slower than expected, it is much faster in cracks and crevices. More importantly, despite the suppressed melting, the glacier is still retreating, the researchers note.

Thwaites Glacier is sometimes referred to as the “Doomsday Glacier” because of the potential threat to global sea level rise. This glacier is one of the largest and fastest melting glaciers in Antarctica and is located in an area of ​​Antarctica that is warming faster than the rest of the continent. Scientists are particularly concerned that the glacier is held back by an underwater ridge; The loss of this ridge could cause the glacier to collapse and global sea levels to rise by more than a meter. This will have devastating effects on coastal cities and communities around the world, leading to widespread flooding and the displacement of millions of people.

“By adding new observations of incredibly high melting on the west side of Thwaites, we get a broader and more complete picture of the glacier’s interaction with the global ocean,” explains David Holland, Director of NYU’s Fluid Dynamics Department. New York University Abu Dhabi Laboratory and Center for Global Sea Level Change, principal investigator of the US project. “The west coast melting rate is the highest ever in Antarctica, suggesting that the glacier may now be retreating.”

Findings published in two journal articles NatureThis is an important step towards understanding how a Florida-sized glacier contributes to future sea level rise. In particular, the results show that, despite increasing melting under the floating ice shelf, the current melting rate is lower than predicted by many computer models.

A layer of fresher water between the bottom of the ice shelf and the ocean below slows the rate of melting along the flat parts of the ice shelf. Surprisingly, however, the melting created a ladder-like topography at the bottom of the ice shelf. As in these places, rapid melting occurs in ice cracks.

The Thwaites Glacier is one of Antarctica’s fastest-changing glaciers: its ground region – the point where it meets the seafloor – has retreated more than 14 kilometers, or eight miles, since the late 1990s. Most of the ice sheet lies below sea level and is susceptible to rapid, irreversible ice loss that could raise global sea levels by more than half a meter over the centuries.

The new data were collected as part of the MELT project, one of the projects of the British-American international collaboration Thwaites Glacier Collaboration, one of the largest international field campaigns ever conducted in Antarctica. The MELT team conducted ground line observations under the eastern Thwaites Ice Shelf to understand how ice and ocean interact in this critical region.