This study, published today in Proceedings of the National Academy of Sciences, concludes that understanding how the ice field ruptures as it moves over the bedrock is crucial to understanding when this collapse may occur. In addition to identifying the weak points of the glacier, Lhermitte and colleagues created a computer model to predict how such cracking and cracking could affect other Antarctic glaciers in the future.
Lhermitte says the goal of this model was not to predict the exact date when Thwaites will collapse. This is almost impossible right now because there are too many other unknown factors to consider, such as the pace of climate change that is warming both the air and water temperature around the glaciers as well as the movement of ocean currents around Antarctica. (A 201
Instead, Lhermite’s model is an attempt to incorporate inland ice damage into similar global climate models that predict both sea level rise and the future of Antarctic glaciers. “The understanding of how much and how fast these glaciers will change is still unknown,” Lhermitte says. “We do not know the whole process. What we have done with this study is to look at this damage, the demolition of these ice shelves, and what their potential contribution to sea level rise may be. ”
Glacier motion is difficult to predict because ice behaves both as a solid and as a liquid, says Penn State University geoscience professor Richard Alley, who was not associated with any of these studies. Alley says the study of how glaciers break is both new and important because it provides more insight into how quickly they can collapse. In an email to WIRED, Alley compared the science of studying how Antarctic glaciers move to the process of constructing a bridge.
“You do NOT want your bridge to break, and you do not want to have to predict exactly the conditions that will cause it to break, so you design with a large safety margin. We can not ‘design’ Thwaites, so we face these great uncertainties. It is important to quantify parts of it, although one remembers that this is still fracture mechanics, and it can still surprise us in one way or another, ”Alley wrote.
Lhermitte believes his research findings mean that glaciers in Antarctica must be closely monitored in the coming years for signs of rapid change that could lead to an environmental disaster. “It’s these big sleeping giants,” Lhermitte says of Thwaites and Pine Island glaciers. “We are beginning to be curious whether they will be asleep or awake with major consequences with rising sea levels.”
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