One other day, one other retreating glacier. Today’s casualty is Antarctica’s Cadman Glacier, situated on the western coast of the Antarctic Peninsula.
Using satellite images and in-situ oceanographic measurements to trace Cadman Glacier for greater than three a long time, a team of scientists has reported a dramatic glacial retreat of 5 miles (8 kilometers). The change was quick, occurring over just 2.5 years between November 2018 and May 2021. Following that retreat, the tidewater glacier’s ice shelf — the a part of the glacier that floats on the surface of the ocean, but still stays anchored to land — completely collapsed.
“We were surprised to see the speed at which Cadman went from being an apparently stable glacier to at least one where we see sudden deterioration and significant ice loss,” team lead Benjamin Wallis, a glaciologist on the University of Leeds, said in an announcement.
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Though Cadman Glacier has been thinning for the reason that early 2000s — or possibly whilst far back because the Nineteen Seventies — the team suggests that warmer-than-normal ocean temperatures in 2018 and 2019 (exacerbated, partially, by human-driven global warming) likely accelerated the method, weakening the ice shelf to the purpose of collapse. Because ice shelves typically buttress the land-based a part of a glacier, it’s now expected that Cadman Glacier will lose water more rapidly. Currently, it drains some 2.38 billion tons (2.16 billion tonnes) of ice into the ocean annually, and that rate of flow will likely increase. Such glacial draining directly contributes to sea level rise, which threatens coastal regions across the globe.
And that is only a part of the story.
“What was also curious was that the neighboring glaciers on this a part of the west Antarctic Peninsula didn’t react in the identical way, which can hold necessary lessons for the best way we are able to higher project how climate change will proceed to affect this necessary and sensitive polar region,” said Wallis.
The team hypothesizes that underwater ridges are acting as defensive barriers for nearby glaciers, protecting them from the warming sea — for now, anyway. But with ocean temperatures continuing to rise, subsea geology won’t find a way to guard the glaciers for for much longer. As such, the team considers Cadman Glacier to be a “glaciological tipping point” that may indicate the long run for its neighbors.
“What this latest research shows is that apparently stable glaciers can switch very rapidly, becoming unstable almost by surprise, after which thinning and retreating very strongly,” said Professor Michael Meredith, from the British Antarctic Survey and a co-author of the study. “This emphasizes the necessity for a comprehensive ocean observing network around Antarctica, especially in regions near glaciers which can be especially hard to make measurements.”