Geosciences’ Brian Romans to continue studying sediments collected from Antarctic Ice Sheet
Brian Romans stands on the deck of the JOIDES, near West Antarctica, in January 2018. Behind him is a massive iceberg in the distance.
Brian Romans, an associate professor in the Department of Geosciences, will continue his study of collected sediment samples from seafloor near the West Antarctic Ice Sheet as part of a new, multi-university National Science Foundation funded grant focused on global change.
The grant, totaling $449,000 – with $200,000 going to Virginia Tech – is for three years and includes researchers and students from State University of New York Binghamton, Rice University, and Texas A&M. They will use samples of sediment from Antarctica collected by Romans and a team of geoscientists as part of the International Ocean Discovery Program, Expedition 374, which set sail in January 2018 aboard the JOIDES Resolution.
Romans and fellow geoscientists collected a total of 1,300 meters (an eighth of a mile) of sediment cores during the 2018 expedition, with 300 samples – varying in size – archived at Virginia Tech. Romans will work with Geosciences Ph.D. student Natalia Varela on the project.
Sediments that accumulate on the ocean floor near ice sheets provide a record of past processes, Romans said in 2018. When ice sheets melt, they discharge massive amounts of sediment generated by glaciers as they eroded bedrock on land. This sediment is transported to areas where it can accumulate for long periods of time, resulting in a record that scientists can use to reconstruct ice sheet history, he added.
Long rows of rectangular, gray split sediment cores on the observation table aboard the JOIDES Resolution during IODP Expedition 374. Scientists characterize and describe the sediment immediately after the cores are taken and that basic information provides initial findings and helps guide the development of research projects that happen long after the expedition.
Now, the collected sediment will be analyzed with multiple complementary measurements, including: grain size, composition, chemistry of organic matter, physical structures, microfossil type and abundance, and more.
“Natalia and I will be measuring the size of the sediment particles throughout the core. Something as simple as particle size tells us about the processes that transported the sediment, which is, in turn, controlled by how the ice sheet interacted with the ocean,” Romans said this month. “These particles are small, ranging from clay to fine sand, and we use various instruments in our lab to quantify size. In addition to size, we will also describe the sediment core in detail using measurements that were made on the ship when the cores were collected.”
Among the major concerns related to the study: The more parts of the ice sheet that melt as the Earth warms will lead to higher sea levels, threatening coastal environments and cities worldwide. “How can humanity make decisions about how to prepare for rising seas if our forecasts are so uncertain?” Romans asked.
One answer: Collect details about how the past changes in the ice sheets impacted the ocean sediment samples – which Romans says are “incredibly dynamic” – to help climate scientists improve computer models for ongoing and future climate change events.
“We will reconstruct a history of when the ice sheet was growing and when the ice sheet was shrinking, and will compare that history of ice-sheet behavior to past temperature,” added Romans, an affiliated faculty member of the Virginia Tech Global Change Center. “Studying past ice sheet behavior gives us insight into how ice sheets respond to climate change.”
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