Studying Antartica’s Retreating Glaciers

The western edge of Antarctica is home to Thwaites Glacier, the world’s widest at about 80 miles. But despite its size, it’s losing approximately 50 billion tons of ice per year.

A new study published by University of Houston researchers in the journal Proceedings of the National Academy of Sciences suggests that significant thinning and retreat of both the Thwaites Glacier and another Antarctic glacier, Pine Islands, began in the 1940s. The trend was likely kicked off by an extreme El Niño climate pattern that warmed West Antarctica.

Since then, the authors assert, Thwaites has not recovered, and it is currently contributing to 4% of all global sea-level rise (assuming 3.5 mm annual sea-level rise).

“It is significant that El Niño only lasted a couple of years, but the two glaciers ... remain in significant retreat,” said corresponding author Julia Wellner in a previous interview. The UH associate professor of geology is the U.S. lead investigator of the Thwaites Offshore Research project, an international collaboration whose team members authored the study.

To conduct their research, Wellner and the THOR team took a trip in 2019 to the Amundsen Sea near Thwaites aboard the Nathaniel B. Palmer icebreaker and research vessel to collect marine sediment cores. They then used the cores to reconstruct the glacier’s history from the early Holocene epoch to the present.

“The glacier is significant not only because of its contribution to sea-level rise, but also because it is acting as a cork in the bottle holding back a broader area of ice behind it,” Wellner said. “If Thwaites is destabilized, then there’s potential for all the ice in West Antarctica to become destabilized.”

If Thwaites Glacier were to collapse entirely, global sea levels are predicted to rise by 25 inches. To put this in context, the global sea has risen 6–8 inches over the past 100 years. “What is especially important about our study is that this change is not random nor specific to one glacier,” said lead author Rachel Clark, who earned her Ph.D. in geology at UH. “It is part of a larger context of a changing climate. You just can’t ignore what’s happening on this glacier.”

This wasn’t the first trip to Antarctica for UH. Minako Righter, a researcher in the Department of Earth and Atmospheric Sciences, and her team of six took their own expedition in 2017 to recover 219 meteorites for study. And Wellner recently participated in a 2022 Antarctic expedition to deploy an unmanned submersible that created the very first maps of the underside of a glacier, revealing further clues about future sea-level rise.

Read more about Julia Wellner's work in Antarctica.