NSF-Funded Research Looks into Planet's Climate History

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Asst. Prof. Kate Swanger’s team collects samples from a sandstone boulder in the Olympus Range in Antarctica. 

By Edwin L. Aguirre

From November 2013 to January 2014, Kate Swanger, an assistant professor in the Department of Environmental, Earth and Atmospheric Sciences (EEAS), led an expedition to Antarctica to investigate how the continent’s glaciers have responded to climate fluctuations in the past. Her work is supported by a three-year $124,070 grant from the National Science Foundation (NSF), with Swanger as principal investigator.

Glaciers occupy only about 10 percent of Earth’s land surface but they hold roughly three-quarters of the planet’s fresh water. Most of them are found in Antarctica and Greenland.

Swanger and her team, which includes EEAS graduate students Catherine Radonic and Christopher Ford as well as Ph.D. student Andrew Christ from Boston University, took three days and “countless plane rides” to get to McMurdo Station, the U.S. research facility on Antarctica’s Ross Island, located at latitude 78 degrees south.

Every austral summer, McMurdo Station supports hundreds of Antarctic scientists, organizing and transporting equipment, people, tents and supplies to remote sites across the frozen, desolate landmass. Swanger and her team spent five weeks camped in the McMurdo Dry Valleys, the largest ice-free region in Antarctica.

“This region purportedly has remained free of ice for at least 15 million years, and is therefore an important window into the continent’s long-term glacial, geological and climatic history,” explains Swanger.

The team conducted field work to analyze and date past advances of alpine glaciers.

“Given Earth’s changing climate and its potential future impact on ice volume and sea level, it is crucial to gain a better understanding of past advances and retreats of Antarctic ice, especially under higher carbon dioxide levels in the atmosphere and/or warmer-than-present conditions.”

The team focused on three major existing glacier systems in the McMurdo Dry Valleys, gathering rock samples from surface glacial deposits for exposure dating, conducting on-site experiments to measure the erosion rates of bedrocks and mapping and characterizing the glacial deposits.

“The glacier systems exhibit variable sensitivity to climate change, some responding rapidly to minor warming whereas others only respond to major shifts in climate,” she notes. “Coupled with regional climate modeling, these data will provide critical insight on how sensitive Antarctic ice is to warmer-than-present climates.”