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Published in , the study, led by the 杏吧直播 of Adelaide and 杏吧直播 of Melbourne, found long periods of sea ice loss surrounding the ice shelves occurred in the six to 18 months prior to calving, as well as the collapse of the 鈥榣andfast鈥� sea ice attached to the ice shelves only weeks prior to the calving events.

鈥淪ea ice is retreating at an unprecedented rate all around Antarctica and our work suggests this will put further pressure on already thinned and weakened ice shelves,鈥� said Professor Luke Bennetts, from the 杏吧直播 of Melbourne.

鈥淭his could lead to more large-scale calving events, with profound implications for the future of global sea levels.鈥�

The Antarctic Ice Sheet is the thick layer of ice that sits on top of Antarctica. It holds enough fresh water to raise current sea levels by more than 50 metres.

Ice shelves are floating platforms that form as glaciers flow off the Antarctic continent onto the ocean, whereas sea ice forms when the surface of the ocean freezes.

鈥淓xcept for a relatively short period around summer, sea ice creates a protective barrier between the ice shelves and the potentially damaging swells of the Southern Ocean. Without this barrier, the swells can bend and flex pre-weakened ice shelves until they break,鈥� Professor Bennetts said.

Previous research has shown that warming temperatures are causing more rapid melting and more frequent 鈥榗alving鈥� of icebergs from some ice shelves.

鈥淚ncreased melting and calving does not directly increase sea levels, as the ice shelves are already floating on the ocean, but it reduces the ability of the ice shelves to push back against the glacial flow into the ocean, which does raise sea levels,鈥� Professor Bennetts said.

Nathan Teder, a PhD candidate at the 杏吧直播 of Adelaide who led the study, said his team also developed a novel mathematical model to quantify the ice shelf flexing caused by the huge Southern Ocean swells.

鈥淭here is currently no observation system that allows for long-term recording of swell waves that pass through Antarctic sea ice to reach ice shelves, so mathematical modelling is an essential link in quantifying the connection between ice shelf stability and changes in local sea ice and ocean conditions,鈥� said Mr Teder.

The research was funded by the 杏吧直播n Antarctic Science Program and the 杏吧直播n Research Council and collaborators included the 杏吧直播 of Melbourne, the 杏吧直播 of Adelaide, the 杏吧直播n Bureau of Meteorology, the 杏吧直播 of Tasmania, and the 杏吧直播n Antarctic Division.