According to a new study, the Thwaites Glacier in West Antarctica has been losing ice at an accelerating rate since the 1940s. Previously, scientists thought the glacier only began losing its ice much in the 1970s. This study’s findings are ominous; the glacier has been nicknamed the “Doomsday Glacier” because its collapse could result in disastrous sea level rising.
The study, published on Monday in the journal Proceedings of the National Academy of Sciences, analyzed marine sediment cores taken from beneath the ocean floor to reconstruct the glacier’s history from its present to over 10,000 years ago. They found that the Thwaites Glacier, and its neighboring Pine island Glacier, both lost contact with the seafloor highs in the 1940s.
They believe that a massive El Niño took place at around the same time that these glaciers began to lose their mass.
“Thwaites Glacier plays a vital role in regulating West Antarctic Ice Sheet stability and, thus, global sea-level rise,” the study authors write.
If the Thwaites Glacier collapses on its own, it will cause sea levels to rise by roughly two feet (65 centimeters). And because it is responsible for holding back the West Antarctic Ice Sheet, its collapse could trigger further melting that may spiral into a sea level rise of 10 feet (3 meters) and cause catastrophic global flooding.
“The synchronous ice retreat of these two major ice streams suggests that, rather than being driven by internal dynamics unique to each glacier, retreat in the Amundsen Sea drainage sector results from external oceanographic and atmospheric drivers, which recent modeling studies show are modulated by climate variability," the study authors write.
“That ice streams such as Thwaites Glacier and Pine Island Glacier have continued to retreat since then indicates that they were unable to recover after the exceptionally large El Niño event of the 1940s,” they continue. “This may reflect the increasing dominance of anthropogenic forcing since that time but implies that this involved large-scale, in addition to local, atmospheric and ocean circulation changes.”
The El Nino climate pattern was most likely the initial driving force in warming the waters of west Antarctica between 1939 and 1942. The finding describes a fragile system of ice that, once affected by a major event, does not stop retreating. Human-induced climate change has also continued to propel that warming. But even if humans stopped warming the planet, the ice would not most likely not stop retreating.
“Once an ice sheet retreat is set in motion it can continue for decades, even if what started it gets no worse,” said James Smith, a marine geologist at the British Antarctic Survey and a co-author of the study.
Similar threats have happened long ago in Earth's history and those ice sheets were able to recover and regrow, but Smith says these glaciers “show no signs of recovery, which likely reflects the growing influence of human-caused climate change.”