This study, published today in Notices of the National Academy of Sciences, concludes that understanding how the ice field breaks as it moves through the rock is vital to understanding when this collapse can occur. In addition to identifying weaknesses in the glacier, Lhermitte and colleagues created a computer model to predict how such cracking and distortion could affect other Antarctic glaciers in the future.
Lhermitte says the purpose of this model is not to predict the exact date when the Thwaites will collapse. At present, this is almost impossible because there are too many other unknown factors to consider, such as the pace of climate change, which warms air and water temperatures around glaciers, and the movement of ocean currents around Antarctica. (A 201
Instead, the Lhermitte model is an attempt to incorporate ice cover damage into similar global climate models that predict both sea level rise and the future of Antarctica’s glaciers. “Understanding how much and how fast these glaciers will change is still unknown,” says Lermit. “We do not know the whole process. What we have done with this study is to look at this damage, the rupture of these ice shelves, and what their potential contribution to sea level rise could be. “
Glacier movement is difficult to predict because the ice behaves both as a solid and as a liquid, said Richard Ali, a professor of geology at Penn State University who was not involved in any of the studies. Alley says the study of how glacier fractures are both new and important because it gives more insight into how quickly they can collapse. In an email to WIRED, Ali compared the science of studying how Antarctic glaciers move with the process of designing a bridge.
“You do NOT want your bridge to break and you do not want to predict exactly the conditions that will make it break, so you design with a large safety margin. We can’t “design” Thwaites, so we face these great uncertainties. “Quantifying parts of this is important, although remember that this is still a mechanics of destruction and can still surprise us, one way or another,” Ali wrote.
Lermit believes that the results of his research mean that Antarctic glaciers must be closely monitored in the coming years for any signs of rapid change that could lead to an ecological catastrophe. “They’re these big sleeping giants,” Lermit said of the Twate and Pine Island glaciers. “We’re starting to wonder if they’ll stay asleep or awake with big consequences, with sea levels rising.”
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