Researchers make inroads in study of melting glacier

Researchers at The University of Texas at El Paso are using seismic data to track the structure and movement of Thwaites, the widest glacier on Earth.

Thwaites is a Florida-sized glacier in west Antarctica whose continuous melting plays an outsize role in global sea level rise. On its own, Thwaites currently contributes 4% of all sea level rise, and its collapse could trigger the release of enough ice to raise sea levels by about 25 inches, according to Marianne Karplus, Ph.D., associate professor in the Department of Earth, Environmental and Resource Sciences and the principal investigator on the project.

Now, UTEP scientists are working to understand how the glacier's ice is changing and what it means for the future. By measuring physical properties of the ice and rock below it and understanding which parts of the glacier are moving quickly and why, they hope to map Thwaites' future movement and resulting sea level rise.

UTEP is a member of the Thwaites Interdisciplinary Margin Evolution (TIME) team, which is part of the International Thwaites Glacier Collaboration (ITGC), a consortium of eight research teams from the United States and the United Kingdom that are working together to study all aspects of the glacier's behavior.

Led by Karplus, the UTEP team has traveled to Antarctica four times to measure the motion of the ice sheet and model its future movement. They plan to return later this year.

"This November we will start our fifth and last field season in Antarctica to collect geophysical data that will help us better understand changes to Thwaites Glacier and its future contributions to sea level rise," Karplus said. "Given our recent fascinating discoveries, I am excited to return one last time to observe and listen to the stories the glacier shares with us."

Thwaites' eastern edge—or boundary—is called the eastern shear margin. The ice on one side of the margin is moving much more quickly than the ice on the other side, according to scientists. The cause of the behavior is one of many scientific mysteries about the glacier that the researchers are trying to solve.

Part of the work involves planting sensors in the ice to measure ice-quakes, which are sudden events where ice cracks or breaks, much like an earthquake. Through their recent work on Thwaites, Karplus and her team used seismic data gathered from the sensors to estimate the structure and properties of the ice and rock below it, which are critical for understanding the glacier's overall movement and behavior.

Karplus uses the analogy of a hammer struck against a rock versus a hammer struck against sand. When the hammer hits the dense rock, the energy will quickly reverberate and be felt on the other side of the rock almost immediately. In the loose sand, however, the waves of energy will disperse quickly and hardly be felt. Similarly, seismic waves will travel through dense, cold ice very quickly but will travel through softer—and potentially melting—ice more slowly.

Lucia Gonzalez is a UTEP student in the fifth year of her doctoral degree in geological sciences with a focus on glaciology and geophysics. She was part of the team that traveled to Antarctica from November 2022—February 2023 and planted many of the sensors that measure the icequakes.

"Living and performing scientific fieldwork in Antarctica was one of the most exciting and fulfilling opportunities in my life," Gonzalez said. "From the lifestyle and incredible scenery in such a remote place to worldwide friendships, it was a unique experience."

She added, "I am confident that our team's effort to collect data and produce science on Thwaites Glacier this past and coming season will enhance high-quality research in the coming years."

UTEP has received approximately $970,000 from the National Science Foundation since 2018 to conduct the research. The project's co-principal investigators are Steven Harder, Ph.D., research professor, and Galen Kaip, director of the Seismic Source Facility at UTEP, which provides technical support to researchers.

UTEP graduate students Yeshey Seldon, Tara Sweeney and Michel Luna and UTEP researchers Steven Veitch, Ph.D., and Solymar Ayala Cortez, Ph.D., are also involved with the project. The broader collaborative TIME project research team beyond UTEP includes scientists from the University of California at Santa Cruz, the University of St. Andrews, the University of Oklahoma, the University of Leeds, Stanford University, Cambridge University and Massachusetts Institute of Technology.

Provided by University of Texas at El Paso