Revised Look at Ancient Glaciers Predicts Faster Melting Rate in Antarctica
Scientists report that nearly 14,600 years ago marine-based regions of the Eurasian Ice Sheet melted rapidly, contributing to a major sea-level rise. Does this rapid collapse of massive ice give us clues as to the vulnerability of Earth’s remaining ice sheets?
Joseph D. Ortiz, Ph.D., professor and assistant chair in the College of Arts and Sciences’ Department of Geology at Kent State University, recently authored a “News and Views” article in Nature Geoscience that discusses research carried out by another research team that reassessed the melt history and timing of the collapse of the Eurasian Ice Sheet Complex during the Last Deglaciation.
Ortiz’s article, titled “Ancient Ice Sheet Collapse” summarizes the research and puts it into a context that compares it to future ice sheet melting in Antarctica due to global climate change.
The researchers’ article discusses when the melting started, the melt rate increase, and rise in the sea level. It also mentions the challenges to the use of radiocarbon methods to estimate the age of marine materials.
"As was done in the paper, raw marine radiocarbon ages need to be corrected for not only the change in the radiocarbon age of the atmosphere, which changes through time, but also for the age of the water from which the marine fossils formed,” Ortiz explained. “For example, old carbon absorbed into the bones of modern sea lions alive in the North Pacific today can make them appear centuries older than their actual age. Reservoir correction removes that bias."
The modern West Antarctic Ice Sheet is one of the least stable ice sheets remaining on Earth and it shares a few similarities with the ancient marine-based Eurasian Ice Sheet.
“The rate of melting of the Eurasian Ice Sheet was less than the rate of forcing that the remaining ice sheets on Earth face because of the combined increase in natural and mostly anthropogenic forcing since the deglaciation,” Ortiz said.
In his article, Ortiz mentions that emissions due to fossil fuel consumption and land use expansion paired with climate forcing will likely affect the warming rate for the West Antarctic Ice Sheet.
“Ice shelves and massive marine-based ice sheets have collapsed rapidly in the past and understanding the similarities and differences between then and now will illuminate the possibility of it happening again,” Ortiz said.
To read the full article, visit: https://www.nature.com/articles/s41561-020-0572-7
To learn more, visit Joe Ortiz’s laboratory web page: http://www.personal.kent.edu/~jortiz