Wooster professor publishes article contributing to climate change research

Eva Lyon ’07, visiting assistant professor of earth sciences at The College of Wooster, recently published an article that is an important contribution to climate change research. The Quaternary Research article, “A high-resolution record of Late Holocene drought in the eastern Sierra Nevada (California, USA) from June Lake carbonate geochemistry,” provides a perspective for some of the worst recent droughts in the last millennium and the ongoing drying of the American Southwest. The article was published prior to the devastating California wildfires but lends credence to the drought conditions that led to the January 2025 fires.

“As historic drought conditions become more common in western North America, Late Quaternary hydroclimate records from about 50,000 years ago to present time become vital to understanding current environmental changes caused or influenced by people into a longer-term context,” Lyon said about the research. Lyon and her collaborators examined sediment from June Lake in the Sierra Nevada and analyzed the chemical makeup of minerals formed in the lake over time. They were able to reconstruct a detailed history of droughts spanning the last 4,600 years. Their findings identified multiple prolonged drought periods, offering valuable context for understanding present-day droughts by highlighting natural climate variability.

The researchers used well-dated sediment cores from Sierra Nevada’s lakes to establish a high-resolution record of drought in the eastern Sierra Nevada. Using oxygen and carbon stable-isotope rations and high-resolution scanning X-ray fluorescence counts of calcium and titanium, they identified six intervals of past droughts that extended the drought history by nearly 5,000 years.

“A key objective of this study was to resolve the historic water movement and distribution in the eastern Sierra Nevada associated with the Late Holocene Dry Period that occurred between 3,500 to 2,000 years ago and the Medieval Climate Anomaly from about 1,000 years ago,” Lyon said. “The records will be useful in assessing climate models to better plan for future environmental variability. The work is particularly important as the world moves into the greenhouse climate of the future.”

For the College, this study is important because it offers a tangible example of how earth science research methods can be used to study past climates—something that is relevant to students who are interested in geology, environmental science, and climate studies. It also highlights the relevancy of Wooster’s earth science faculty research.

Before her current role with the college, Lyon was a geology major and political science minor at Wooster, where she was a student athlete on the women’s varsity basketball and softball teams and a member of the geology club.

Posted in News on March 10, 2025.