This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A study led by a Montana State University research professor reveals how climate and hydrothermal activity have shaped the vegetation, wildfire and aquatic ecosystem histories of the Yellowstone Plateau over the past 15,000 years. The results of the project were published in the journal Proceedings of the National Academy of Sciences.
Cathy Whitlock, MSU Regents Professor emerita of Earth sciences in the College of Letters and Science and the first scientist to be elected to the National Academy of Sciences from a Montana university, has spent decades working in the Greater Yellowstone Ecosystem. Her interest in Yellowstone National Park's Lower Geyser Basin was piqued in 2020 after she and co-author Chris Schiller took sediment cores from the bottom of one of the basin's small lakes. They noticed that its contents differed from those in lakebeds in other parts of the park, suggesting that distinct geologic factors may have influenced the lake's evolution.
At about the same time, she read a paper speculating that a lack of water in the geyser system caused Old Faithful to stop erupting in the early 13th century for about 100 years. As founder and past director of MSU's 22-year-old Paleoecology Laboratory, which studies how past ecosystems responded to changing climates, Whitlock said the opportunity to learn more about Yellowstone's geyser basins was irresistible but also required the expertise of many scientific disciplines. "I thought, 'Well, there have been long, dry periods in Yellowstone in the past, some of them lasting for several centuries.
I wonder if we could document how periods of sustained drought affected ancient geyser activity,'" she said. Collaborators on the project included MSU professor of Earth sciences Dave McWethy, two MSU postdoctoral researchers, two MSU students and scientists from the U.S. Geological Survey, Oregon State University, Manchester University and Colorado State University.
Throughout her career, Whitlock has reconstructed the histories of ecosystems from tiny clues deposited over time in layers of lake sediments. By examining sediment cores, scientists can pinpoint the age of the layers through radiocarbon dating or from buried evidence of known natural events, such as past volcanic eruptions. Pollen assemblages tell scientists what type of vegetation was present at particular times.
Layers with abundant charcoal identify past wildfire events. The concentration of arsenic and cesium and the composition of the diatoms in the sediments provide information on changes in hydrothermal activity, lake chemistry and water depth. In this study, the team collected core samples from small lakes of different ages in the Lower Geyser Basin, which is Yellowstone's largest geyser system.
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