New Research Links Sea Ice Loss to Antarctic Ice Shelf Calving Events

Recent research published in *Nature Geoscience* has unveiled significant correlations between sea ice loss and calving events of Antarctic ice shelves. Conducted by a team from the University of Adelaide and the University of Melbourne, this groundbreaking study tracked ice shelf dynamics, sea ice conditions, and ocean swell waves over several years, particularly leading up to three major calving incidents in Antarctica.

The study reveals that extensive periods of sea ice loss occurred in the six to eighteen months preceding these calving events, along with the collapse of landfast sea ice shortly before the iceberg breakage. Professor Luke Bennetts from the University of Melbourne, a lead researcher on the project, emphasized that the rapid retreat of sea ice poses increasing threats to the stability of already weakened ice shelves, potentially leading to further large-scale calving events that could have profound implications for global sea levels.

"Sea ice acts as a barrier, protecting the ice shelves from the damaging swells of the Southern Ocean. The current trends indicate that without this protective layer, the swells can exacerbate the flexing and breaking of ice shelves," said Professor Bennetts.

The Antarctic Ice Sheet, which contains enough freshwater to raise global sea levels by over 50 meters, is particularly vulnerable. Ice shelves are formed as glaciers flow from the Antarctic continent into the ocean, while sea ice is formed through the freezing of ocean water. The recent findings highlight that the increased melting and calving of ice from these shelves does not directly contribute to rising sea levels, as the ice shelves float. However, this process diminishes their ability to resist glacial flow into the ocean, indirectly affecting sea levels.

Nathan Teder, a PhD candidate at the University of Adelaide and the study's lead author, noted that a novel mathematical model was developed to quantify the flexing of ice shelves caused by the swells of the Southern Ocean. "Currently, there is no systematic observational system to monitor long-term swell waves that interact with Antarctic sea ice. Hence, mathematical modeling is crucial for understanding the connection between ice shelf stability and changes in local sea ice and ocean conditions," Teder stated.

The research, funded by the Australian Antarctic Science Program and the Australian Research Council, included collaborations with the Australian Bureau of Meteorology, the University of Tasmania, and the Australian Antarctic Division, among others.

The implications of this research are significant, contributing to a clearer understanding of how climate change impacts polar ice dynamics and global sea levels. The study calls for heightened awareness regarding the fragility of the Antarctic ecosystem and the urgent need for further research to monitor these changes effectively.

In summary, as sea ice continues to retreat at unprecedented rates, the potential for more frequent calving events from Antarctic ice shelves increases, raising concerns for coastal communities worldwide. Continued scientific inquiry is essential to assess and mitigate the risks posed by these environmental changes.