Geosciences Associate Professor Brian Romans began his 2018 quite unlike most people. On Jan. 5, leaving from New Zealand, he set sail on the International Ocean Discovery Program, Expedition 374 for the Southern Ocean, just off the west coast of Antarctica. There, he and other scientists drilled into the ocean floor in an attempt to better understand how polar ice sheets respond to climate change.
“Earth scientists have shown that regions near the poles — the Arctic and Antarctic — are highly sensitive to changes in global climate," Romans said. “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.”
One of the largest continental ice sheets on Earth, the West Antarctic Ice Sheet, is experiencing more warming than other significant ice sheets. Ongoing monitoring and the seeking of new data from drilling efforts in this location by climate scientists, glaciologists, and oceanographers were long seen as vital. Measurements from the past several decades of ice sheet change could be a missing part of the picture.
Aboard the JOIDES Resolution, Romans — _an associate professor with the Department of Geosciences — _and his collaborators recovered a total 1.2 kilometers (equal to seven-tenths of a mile) of sediment core from five different sites along the Antarctic continental margin in the Ross Sea. The archived material contains an astounding record of environmental change from roughly 17 million years ago to near the present day.
Preliminary analysis conducted during the expedition suggests significant changes in the size and extent of the West Antarctic Ice Sheet, Romans said after his return in early March. These observations and more to come will be used to reconstruct models of environmental conditions, including ocean temperature, chemistry, and circulation.
“The end of the expedition is really just the beginning of the research in a way,” Romans said.
Sediment core collected near Antarctica
The journey so far south will stay with Romans. “Being out in the open ocean on a research vessel, not seeing land for several weeks, is an interesting experience,” he said. “On one hand, there's a feeling of complete separation from the terrestrial world being out in this environment that makes up three-quarters of our planet. On the other hand, humans are not suited to this environment, we can only view it from the safety of the ship. So, there's a paradoxical feeling of being out in the open, but also confined. In terms of quiet, it's almost never quiet. The noises of the ship's propulsion, drilling activities, and the rest are a constant.”