Antarctica’s ice shelves may be melting much faster than scientists previously anticipated — a phenomenon that could ultimately accelerate sea level rise, a new study has found.
Researchers at the California Institute of Technology and NASA’s Jet Propulsion Laboratory came to this conclusion by deploying a new model showing how dense, warm ocean water can get trapped along Antarctica’s icy coast and speed up melting.
Their model, detailed in Science Advances on Friday, homes in on a “narrow ocean current” adjacent to the coast that the authors described as “often-overlooked.”
Using the model, they simulated how rapidly flowing freshwater — melted from the ice shelves — can trap the warm ocean current at the base of the ice and thereby hasten the melting process.
“If this mechanism that we’ve been studying is active in the real world, it may mean that ice shelf melt rates are 20 to 40 percent higher than the predictions in global climate models,” co-author Andy Thompson, a professor of environmental science and engineering at Caltech, said in a statement.
Ice shelves are outcroppings of the Antarctic ice sheet, located where ice juts out from the land and floats on top of the ocean.
These shelves, which can be hundreds of meters thick, serve as a protective buffer for mainland ice — preventing the entire ice sheet from flowing into the ocean, according to the researchers.
As both the atmosphere and oceans warm due to a changing climate, the speed at which ice shelves are melting is increasing, the authors warned. Such conditions also therefore jeopardize their ability to block the flow of the ice sheet into the ocean, they added.
The study’s release comes amid a high-traffic week for research on the Earth’s poles.
On the opposite side of the planet, scientists showed on Thursday that the Arctic, too, is warming at a more rapid pace than previously assumed.
Yet another research team revealed on Wednesday how humans could potentially thwart the worst impacts of climate change on the East Antarctic Ice Sheet.
The Caltech-NASA researchers, however, focused their study on the West Antarctic Peninsula. This icy mass protrudes out of the higher polar latitudes and into lower, warmer altitudes, and has undergone the most dramatic changes due to climate change, they explained.
“There are aspects of the climate system that we are still discovering,” Thompson said, noting that improvements in modeling ocean, ice and atmosphere interactions have helped scientists make more accurate predictions, with less uncertainty.
“We may need to revisit some of the predictions of sea level rise in the next decades or century — that’s work that we’ll do going forward,” he added.