Scientists have reconstructed the past life of Antarctica's "Doomsday Glacier" and discovered how it started retreating rapidly in the 1940s. The glacier, also known as Thwaites Glacier, is about the size of Florida and accounts for around five per cent of Antarctica's involvement in sea-level rise around the world. For years, scientists knew that the glacier had been losing ice at an accelerating rate, but they didn't know exactly when significant melting began. However, now there is an answer to this question.
According to a new study published in the journal Proceedings of the National Academy of Sciences, researchers analysed marine sediment cores extracted from beneath the ocean floors. They found that the glacier began to significantly retreat in the 1940s because of a very strong El Nino event - a natural climate fluctuation which tends to have a warming pact. Since then, the glacier has been unable to recover, which may reflect the increasing impact of human-caused global warming, as per the report.
Thwaites is called the "doomsday glacier" because of the high risk of collapse and the threat to global sea level. The glacier already contributes 4% of sea level rise as it sheds billions of tons of ice a year into the ocean. Its complete collapse could raise sea levels by more than 2 feet, CNN reported.
Previously, scientists had announced that the glacier is melting at a faster rate than previously expected. "Thwaites is really holding on today by its fingernails, and we should expect to see big changes over small time scales in the future - even from one year to the next - once the glacier retreats beyond a shallow ridge in its bed," Robert Larter, a marine geophysicist who co-authored the study published in Nature Geoscience, said.
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International Thwaites Glacier Collaboration, in an estimate released in 2020, had said that if the "doomsday glacier" dissolves fully, it will lead to four per cent of climate change-caused sea-level rise. They had further said that a sudden collapse would raise sea levels 25 inches more, causing catastrophic global flooding.
The latest findings are alarming because they suggest that once big changes are triggered, it's very hard to stop them, said James Smith, a marine geologist at the British Antarctic Survey and a study co-author. "Once an ice sheet retreat is set in motion it can continue for decades, even if what started it gets no worse," he told the outlet.
