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  New Research from Antarctica Affirms the Threat of the ‘DoomsdayGlacier,’ but Funding to Keep Studying It Is Running Out.

In a worst case scenario, rising global temperatures and marine heatwaves could melt enough of the Thwaites Glacier and other Antarctic ice to raise sea levels 10 feet by the early 2100s.

Inside Climate News, By Bob Berwyn, February 26, 2024

“………………………………………………………….. It took a whole day of sailing just to monitor and map the front of the Thwaites Glacier’s floating shelf, he said, with ice cliffs in some places towering several hundred feet above the water, marking the abrupt edge of an ice expanse about the size of Nebraska and averaging between 2,500 and 4,000 feet thick. If all the ice melts, it would raise average global sea level about 2 feet.

The sediment samples Kirkham and other scientists collected four years ago provided the data for a study published Monday in the Proceedings of the National Academies of Sciences that affirms one of the most serious concerns about Antarctica—that an irreversible meltdown of some of the frozen continent’s ice masses has already started.

“You just can’t ignore what’s happening on this glacier,” said lead author Rachel Clark, a University of Houston ice researcher who also works with the International Thwaites Glacier Collaboration, a team that has been trying to figure out just how fast the vulnerable ice will melt. But, she said the new study is important because it shows that the melting is not just random or limited to one glacier.

“It is part of a larger context of a changing climate,” she said. 

Not Just Thwaites

After analyzing the chemistry and other characteristics of seafloor sediment grains from various depths and different locations near the floating edge of the glacier, the team’s members were able to show that the glacier had been relatively stable for nearly 10,000 years, since the end of the last ice age, but that it started to retreat in the mid-1940s.

Shifts in regional winds and associated changes in ocean currents are pushing more relatively warm water toward Antarctica’s frozen fringe, melting the ice and loosening it from rocky seafloor anchor points that have held the floating part of the glacier in place for thousands of years. As the ice melts away from the pinning points, it can float to sea and disintegrate faster, allowing the glacier behind it to accelerate toward the ocean. In the last 30 years, the amount of ice flowing out to sea from the Thwaites and Pine Island glacial areas and their associated floating ice shelves has doubled.

……………………………………the Thwaites Glacier, and the neighboring Pine Island Glacier, have kept retreating since the 1940s. …………………..

While the Thwaites Glacier has been identified as being among the most vulnerable to pinning point loss, a similar pattern of melting and retreat in many other Antarctic glaciers and ice shelves at least since the 1970s was documented in a separate study published Feb. 21 in Nature. 

………………………………………………………… “We already seem to have pushed the climate and ice sheet system past certain irreversible thresholds, and need to observe and understand more about Thwaites, not less,” said Pam Pearson, founder and director of the International Cryosphere Climate Initiative. “Pleas of ignorance will be little comfort to future generations displaced by Antarctic sea-level rise that we could have stopped had we only acted in time.”  https://insideclimatenews.org/news/26022024/new-research-from-antarctica-affirms-threat-of-doomsday-glacier-but-funding-is-running-out/

March 4, 2024 - Posted by Christina Macpherson | ANTARCTICA, climate change, oceans