– January 29, 2020 – Science
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- Antarctica’s largest glacier continues to melt, but not as fast as expected
The Pine Island glacier is the largest in Antarctica. It is also the one that is melting the fastest under the influence of climate change In fact, another peculiarity is that it contributes enormously to the global rise of the oceans. Scientists are trying to understand how it is melting, in order to anticipate its evolution – and thus that of sea-level rise. A study published in Nature Geoscience on January 27, 2020 brings new elements – in contradiction with old assumptions.
The rate of melting of this glacier quadrupled between 1995 and 2006. Since then, many studies have suggested that this rate has only increased exponentially, while others suggest a more moderate rate. This new study proposes a new model to settle the debate.
Researchers at the University of Bristol, England, have used data from a European Space Agency satellite, CryoSat, to establish new models of glacier melting over the past decade. This satellite has the particularity of mapping glacier levels: scientists can identify the rate of melting in each zone as well as the local speed of this melting.
As a result, there’s good news and bad news. Let’s start with the good news: according to the research paper the rate of ice loss from the central trunk of the glacier has been reduced by five times. The bad news is that on the glacier margins, the melting of the ice has increased enormously. Simply put, the study suggests that the boundary at which the glacier touches the earth’s surface, where it does not float, is not going to be only modestly pushed back in the coming decades.
The “grounding line” is the border where the glacier no longer touches the ground // Source: Hannes Grobes
The main “body” of the glacier will therefore be preserved. On the other hand, it will continue to lose overall. Jonathan Bamber, author of the study, puts the conclusions into perspective: “It might sound like good news, but it’s important to remember that the glacier is still expected to lose mass in the future and that this trend will increase – just not as quickly as models suggest. »
The Pine Island glacier is therefore, perhaps, only partially condemned. This study serves as a reminder that ecological measures to reduce the impact of climate change on ice melting are all the more important since all is not “lost”. Although ocean warming reached a new record in 2019, glaciers are still present and it is not impossible to slow down their melting.
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