Major Antarctic Glacier Passed a Tipping Point In the Last 80 Years, Research Revealshttps://phys.org/news/2023-12-major-antarctic-glacier-years-reveals.htmlResearchers have now been able to confirm that Pine Island Glacier underwent a rapid, unstable retreat at some point between the 1940s and 1970s, leading to an irreversible loss of ice over several decades.Between the 1940s and 1970s the glacier, which was 40km more advanced than its present-day position, detached from a seabed ridge. It underwent a rapid retreat until it temporarily stabilized on a shallow part of the seabed in the late 1980s.
While their study suggests that this accelerated phase of mass loss may now have come to a halt, their results indicate that by the early 1970s the glacier had retreated to a point where it could not recover its original mass and position during colder conditions. This confirms that the glacier's retreat during this period is irreversible, meaning it has passed a tipping point.
The researchers also applied their numerical model to predict the future behavior of the glacier in a separate study and have found that it will again enter periods of rapid retreat unless global warming is kept within limits.
Professor Mattias Green, Professor of Oceanography in the School of Ocean Sciences at Bangor University, said, "The investigation highlights the important interactions between the ocean and the glaciers in Antarctica. The trigger of the historical retreat was possibly an episode of warm ocean water entering the area of Pine Island Glacier, and even when conditions returned to the cold state, the retreat continued. This is quite concerning for the future state of Pine Island Glacier and its neighbors in a warming world.
Brad Reed et al,
Recent irreversible retreat phase of Pine Island Glacier,
Nature Climate Change (2023).
https://www.nature.com/articles/s41558-023-01887-y