An international team of climate researchers from the United States, the United Kingdom, and other nations has pinpointed the trigger that set Thwaites Glacier in West Antarctica on a path of rapid melt 80 years ago. The discovery appears in the scientific journal Proceedings of the National Academy of Sciences.
Thwaites Glacier spans an ice mass roughly the size of Florida, about 192,000 square kilometers. It has earned the nickname Doom- sday Glacier because its melt could release enough water to raise global sea levels by roughly 60 centimeters. The glacier has been thinning at an accelerating rate since the 1980s, contributing to an estimated 4% rise in sea level over recent decades.
Researchers traced the retreat back to the 1940s, when an unusually intense El Niño event warmed the Pacific Ocean. That heat pulse persisted from 1939 through 1942 and also affected Pine Island Glacier, located to the north of Thwaites. The study notes that even a short-lived thermal event can set in motion long-term processes that endure for decades.
As the system destabilizes, ice loss continues. The glacier carries significant weight beyond its contribution to sea level because it acts as a bottling cork for a much larger expanse of West Antarctic ice. If Thwaites loses stability, the surrounding ice sheet could face destabilization, potentially altering regional ice dynamics and climate feedbacks for years to come, according to the study’s co-authors. One co-author, a geology professor from the University of Houston, highlighted the broader implications for West Antarctica if this melting progresses. Research teams emphasize that ongoing monitoring and modelling are essential to understanding future scenarios and informing coastal planning and climate policy.
Earlier forecasts warned that major ice detachments could occur from the Thwaites system, underscoring the glacier’s role in the stability of the West Antarctic ice sheet. Continued observation and data integration are crucial as scientists work to refine projections and reveal how local warming episodes may shape long-term sea level trends. These findings align with a growing body of work that seeks to quantify the cascade of effects from discrete warming events and their capacity to influence distant ice masses over multi-decade horizons.
Notes from researchers indicate that the identified trigger has a lasting impact on ice dynamics, reinforcing the value of sustained, cooperative international research efforts in Antarctic science. The work adds to the knowledge base about how climate variability interacts with ice sheets and emphasizes the importance of incorporating historical climate episodes into modern predictive models. The study’s insights are expected to inform future expeditions, remote-sensing campaigns, and numerical simulations aimed at evaluating potential outcomes for global sea level and regional environmental systems.