A minor ocean circulation that is often ignored by forecasting models due to its modest size might be responsible for the melting of Antarctic ice shelf 20% to 40% quicker than projected.

Specifically, the study headed by researchers at the California Institute of Technology (Caltech) and published in the journal Science Advances suggests that this circulation concentrates warm water at the ice’s base, facilitating melting. A possible explanation for the recent acceleration in the rate of volume loss from the West Antarctic ice shelf might lie in this process.

The ice shelves are an outcropping of the Antarctic ice sheet that extends out into the ocean; these platforms, which can be hundreds of meters thick, serve as a protective buffer for the mainland ice, preventing the entire ice sheet from calving into the ocean and dramatically raising global sea levels.

The Antarctic Coastal Current, which runs counterclockwise around the entire continent and is only about 20 kilometers wide, has been omitted from current models, despite the fact that its presence would likely increase the rate at which these areas melt due to climate change. This is according to the study’s authors.

Fresh water from the melting ice is transported by the current across the continent, as shown by the findings and backed up by data acquired by the researchers themselves.

By staying at the surface due to its lower density, fresh water exacerbates the melting of ice shelves by trapping warmer salt water against their undersides.