Two new studies published in the journal Nature have shown that Antarctica’s Thwaites Glacier, known as the “Doomsday Glacier,” is melting rapidly in unexpected ways. The Thwaites Glacier is the size of Florida and is located in West Antarctica. An ice shelf that protrudes out onto the surface of the ocean helps hold the glacier in place, acting as a cork, and defending against sea-level rise. The ice shelf is, however, highly vulnerable to warming oceans. While melting underneath much of the ice shelf is slower than anticipated, deep cracks and “staircase” formations in the ice are melting much faster. As climate change accelerates, the Thwaites Glacier is rapidly changing. Every year it sheds billions of tons of ice into the ocean, contributing about 4% of annual sea-level rise.
The complete collapse of the Thwaites Glacier could lead to sea-level rise of more than two feet, which would devastate coastal communities worldwide. It also acts as a natural dam to the surrounding ice in West Antarctica, and scientists have estimated that global sea-level rise could ultimately be around 10 feet if the Thwaites Glacier collapsed. The ice shelf could disintegrate much sooner than that, causing an unstable, potentially irreversible retreat of the glacier.
The team of US and British scientists from the International Thwaites Glacier Collaboration used a hot water drill to bore a hole nearly 2,000 feet deep into the ice to survey the glacier. The instruments sent down to take measurements included a torpedo-like robot called Icefin. The results of the research revealed that the rate of melting beneath much of the flat part of the ice shelf was lower than expected. A layer of colder, fresher water at the base of the glacier between the ice shelf and the ocean was suppressing the melting. The scientists also found that the underwater glacial landscape was much more complex than anticipated, with staircase-like terraces and crevasses contributing to instabilities in the glacier.
The findings are consistent with a slew of other studies pointing to the rapid melting of the Thwaites Glacier. A 2021 study found that the ice shelf could shatter within the next five years, while last year, scientists warned that the Thwaites Glacier is hanging on “by its fingernails” as the planet warms, with the potential for rapid retreat in the coming years. The new research provides “the missing pieces” to determine exactly how this change is happening, according to Britney Schmidt, an associate professor at Cornell University and a lead author on one of the papers. The research can help make more accurate projections about sea-level rise, which can be used to mitigate climate change and protect coastal communities.