Climate change destroys the farthest regions of the Earth. At the Thwaites glacier in Antarctica, scientists have found a massive cavity – roughly two thirds of the Manhattan area – which is growing in ice for decades.
The hole lurks beneath the surface of the Florida-sized glaciers and measures 1000 feet from top to bottom, researchers say in a study published Wednesday Scientific progress, The research was conducted by researchers from NASA's jet engine, the University of California Irvine, the German Space Center, and the French University of Grenoble Alpes.
The cavity was discovered by data from NASA's IceBridge operations and space radar projects documenting Thwaites' behavior between 1992 and 2017.
Pietro Milillo, a radar scientist from NASA's jet engine and the lead author of the study, called him "an upsetting discovery".
"This hole is large enough to contain 14 billion tons of ice," Milillo said in an e-mail. "To compare these numbers at the human level, 1 billion tons is water consumption in Los Angeles in one year."
Illustration of the Thwaites glacier in Antarctica. Image: NASA Jet Propulsion Laboratory
Antarctic scientists have known for Thwaites's "weak underground" for decades. Nevertheless, authors suspect that previous models underestimated the cavity and melting rate.
Glacial drainage is responsible for up to 10 percent of the annual global sea level rise, according to estimates by the National Science Foundation. If Thwaites completely dissolve, the world's oceans can grow by almost two feet.
Tracking Ice Loss is not a simple podvig. Antarctic glaciers are often too large and too insulated to accurately measure the ground.
Instead, the team used a low-Earth satellite fleet of satellites and radar-propelled aircraft flying through the ice to monitor Thwaites over time. It revealed "different withdrawal mechanisms," Milillo said.
Where the cavity appears on the west face of the glacier, the earthing line – the point where Thwaites is located in the epicontinental belt – has been separated from the rocks by 0.4 to 0.5 miles a year since 1992.
The cycle is maintained as the hole grows; as more water and heat captures under the ice, it gets faster melt. Most of the 14 billion tons of ice has disappeared in the last three years, according to a study.
East, Thwaites's earthing line goes through small channels, "as if the fingers come under the glacier to sink it from below," Milillo described. Here, the rate of retreat accelerated from 0.4 miles per year between 1992 and 2011 to 0.8 miles per year from 2011 to 2017. (However, the Thwaites western region is still faster than the east.)
Many things are responsible for withdrawal, such as topography, ice drift and melting by the mass of hot, saltwater waters. "The interactions of the oceans are more complex than they were before," Milillo said.
American and British science agencies have recently embarked on a five-year expedition to Thwaites in an attempt to better understand its scary potential for rising sea levels at the mass level.
"How fast, that's our mantra," said Robert Larter, a British Antarctic research scientist, on BBC News Wednesday: "These are questions about Thwaites."
Thwaites joins an ice cap on West Antarctica, which also lost ice without precedent. Separate research suggests that large areas have retreated to a "no return point", and the entire ice cover in West Antarctica could raise sea level by 10 feet.
In the near future, Mililo expects the new generation of satellites to "be able to provide more accurate and more frequent measurements across Antarctica and Greenland."