January 3, 2018 | Geosciences Associate Professor Brian Romans is setting sail for the Southern Ocean with a group of scientists who will drill into the ocean floor offshore of West Antarctica to better understand how polar ice sheets respond to climate change.
Romans’ two-month trip, departing Jan. 5 from New Zealand, is part of the International Ocean Discovery Program, Expedition 374. Working alongside 30 geologists and paleoclimatologists from around the world, Romans will drill into ocean floor in the Ross Sea, offshore of West Antarctica, with the goal of recovering sediments that can show the dynamic history of the region’s vast ice sheet.
“The goal of our expedition to better understand how polar ice sheets respond to climate change,” said Romans, on faculty with the Department of Geosciences, part of the Virginia Tech College of Science, and a researcher with the Global Change Center at Virginia Tech, part of the Fralin Life Science Institute. The work ties in directly to Virginia Tech’s efforts in Global Systems Science as a research focus.
“The eventual impact of this research will be to improve climate models used to forecast future global change,” Romans said. “Earth scientists have shown that regions near the poles — the Arctic and Antarctic — are highly sensitive to changes in global climate. This so-called ‘polar amplification’ phenomenon can result in warming of both the atmosphere and the oceans, which can, in turn, affect the stability of ice sheets. One of the most critical questions in climate science is if the well-documented melting of land ice could accelerate, leading to even more rapid melting and, ultimately, collapse of an ice sheet.”
Accelerated ice sheet melting presents a global threat, with sea levels rising much faster than currently predicted. Additional consequences are numerous, including changes in ocean circulation patterns and in how much of the sun’s energy is reflected back to space by vast, white-colored ice sheets. One of the largest continental ice sheets on Earth, the West Antarctic Ice Sheet, is experiencing more warming than other significant ice sheets, Romans added.
Ongoing monitoring and the seeking of new data from drilling efforts in the West Antarctic Ice Sheet by climate scientists, glaciologists, and oceanographers is vital. Observed measurements from the past several decades of ice sheet change could be missing part of the picture.
For example, Romans will query how did the West Antarctic Ice Sheet respond to climate change during longer time periods, from centuries to millions of years. “Studying this history will improve our ability to foresee changes that may happen in the future,” Romans said.
Romans previously has sailed on the International Ocean Discovery Program’s primary research vessel, the JOIDES Resolution. In 2012, he traveled to the North Atlantic Ocean, near Newfoundland, Canada, where he helped recover sediments recording oceanographic change going back from 50 million years.
Sediments that accumulate on the ocean floor near ice sheets provide a record of past processes, said Romans. 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.
A melting ice sheet also produces icebergs where the land-based ice sheet meets the ocean. These icebergs contain rocks and sediment that can became embedded within the ice as the glacier eroded into the landscape. As icebergs break off and float away, eventually melting, the rocky debris drops to the ocean floor, where it becomes part of the sedimentary record. Documenting the presence, number, and characteristics of the “dropstones” can be used to study iceberg discharge from an ice sheet, said Romans.
“Although a scientific ocean drilling expedition like ours is a complex and costly endeavor, it is the best way to efficiently collect the sediment samples necessary to do this research,” Romans said.
The International Ocean Discovery Program is an international science collaboration to acquire sediments and rock from beneath the ocean floor to study fundamental Earth processes. Scientists from U.S. institutions participating in the expeditions are supported by the National Science Foundation.
Follow Brian Romans on his expedition
Romans will be updating his research progress and posting photos from offshore of West Antarctica, at his research blog. He also can be found on Twitter and Instagram. To follow the JOIDES Resolution ship, look for them at Twitter, Instagram, or Facebook.
Story by Steven MackayShare