DEKALB, Ill. - The National Science Foundation has awarded a prestigious Faculty Early Career Development Program…
DeKalb, Ill. — The National Science Foundation (NSF) has awarded a $271,000 grant to NIU Board of Trustees Professor Reed Scherer and colleague Christine Siddoway of Colorado College to support their research on the vulnerability of the West Antarctic Ice Sheet (WAIS).
The funding support over two years includes roughly six paid research positions for NIU undergraduate and graduate students, plus funding for student researchers at the Colorado Springs college.
Scientists are concerned that under a warming climate the WAIS, which is about the size of the United States east of the Rockies, might be susceptible to releasing its ice as armadas of giant icebergs into the Southern Ocean. Such events would raise global sea level and threaten coastlines worldwide.
To best-assess the threat, scientists want to know whether such events occurred in the geologically recent past—from 3 million to 120,000 years ago—during warm intervals of past glacial-interglacial cycles.
“We want to learn how quickly the ice sheet disappeared during natural global warming periods,” said Scherer, a professor in the Department of Geology and Environmental Geosciences. “The information will inform us about the future. However, the rate of warming is much faster now, so we can expect the ice sheet will respond much quicker.”
Used for research since 1985, the floating laboratory has drilled thousands of deep holes in the sea floor, retrieving cores that, for experts like Scherer, read like history books of past Antarctic climates.
Scherer says the 2019 ocean drilling, near the most vulnerable sector of the WAIS, yielded seafloor geologic records demonstrating times when icebergs dropped large volumes of sands and pebbles, called ice-rafted detritus (IRD), in deep water of the Amundsen Sea. In the same seafloor layer as the IRD can be found an abundance of microfossils or diatoms (algal plankton), which indicate high biological productivity in the open ocean.
“Diatoms provide powerful evidence of temperature and ocean productivity changes in the past, that when linked to time, can translate into rates of ice sheet drawdown,” said Scherer, an expert in the study of the microfossils.
The new NSF-funded project will investigate sediment intervals where IRD coincides with evidence of high diatom production, to test whether these two criteria indicate rapid ice sheet collapse.
“The new sediment cores provide a complete, uninterrupted record of a time of dramatic fluctuations of ice sheet size that occurred over the last 3 million years,” Scherer said. “They give us the means to obtain clear answers to the question whether ice sheet collapse occurred in the past, offering clues to the ice sheet’s potential future.”
Scherer and his graduate students are already analyzing core samples. Professor Siddoway and her students will provide geochemical analyses of IRD pebbles to help trace the source of the icebergs to likely on-land sites.
The results of the study will provide critical data for designing, constraining and testing the next-generation computer models that will be able to determine the likelihood and timing of future ice sheet collapse in a warming world.
In addition to training students from diverse backgrounds, the project will include public outreach efforts.
Media Contact: Tom Parisi
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