Si ritirano rapidamente i ghiacci di Thwaites in Antartide

From the sky, scientists have registered something wrong – not a good sign

There is a giant glacier in Antarctica that could cause sea levels to rise dramatically and in shorter time than expected. This is what emerges from a new study, published on 5 September 2022 in the journal Nature Geoscience, and it doesn’t bode well. Why the Thwaites glacier in Antarcticanicknamed the “doomsday glacier”, is disintegrating, indeed it is collapsing faster than it has done so far.

It is no coincidence that the glacier in question has a similar nickname. The Thwaites has always caught the attention of experts because based on its dissolution and the changes that affect it more generally, they can estimate how and how much sea level would rise. And it is thanks to a mapping of the area, made for the first time at very high resolution, that they were able to observe how its withdrawal phase has not simply begun, but has also undergone one dizzying acceleration.

The new study on the Thwaites glacier in Antarctica

The retreat of ice in Antarctica is certainly no secret. For some decades the phenomenon has intensified and has undergone a rapid lash, to the point of recording very worrying data. The most dramatic consequence of human activity and it is not an exaggeration: the balance on which the Planet relied has gradually lost, giving way to a spiral of changes not at all reassuring. Temperatures rise to levels never recorded before, so much so that a no-return date has already been predicted in shorter times than you think, the perennial ice melts and collapses on themselves and the sea level rises.

The study published in Nature Geoscience he is not the first to deal with the retreat of ice in Antarctica or the Thwaites glacier in particular, always under the watchful eye of experts. The reason is very simple: Thwaites is a gigantic sea ice shelf, more than 1 km deep and with a maximum width of about 120 km. But it is not only the size that makes it so important: unlike other glaciers connected to the mainland it is, in fact, rooted in the seabed, a characteristic that makes it more vulnerable to water overheating and human-induced climate change in general. Think that the melting of the Thwaites glacier alone accounts for about 4% of the annual sea level rise.

Thanks to the research team of marine geophysicist Alastair Graham, stationed at the College of Marine Science at the University of South Florida, it was possible to observe for the first time a very high resolution area mapping, recording every slightest change in the morphology of the seabed and the surface of Thwaites. “Our results suggest that very rapid retreat pulses have occurred on the Thwaites Glacier over the past two centuries and possibly into the mid-20th century,” said Dr. Graham.

The impact on sea level

The study essentially shows that in the last 200 years, for a duration of less than six months, the the front of the glacier has lost contact with a ridge in the sea floor, retreating at a speed of more than 2.1 kilometers per year. Although it is not the most dramatic data ever recorded regarding the Thwaites, we cannot say that it is not worrying: it is a value twice greater than the data recorded using the satellites between 2011 and 2019.

The images recorded are certainly extraordinary, but they are also a tool that allow us to “predict” what could happen in the future of the gigantic glacier, and beyond. Experts were able to observe unpublished geological elements, their changes and look like inside a “crystal ball” on the future of the polar ice caps. According to the United Nations, over 40% of the world’s human population lives within 60 miles of the coast, all areas that will be hit hard by thesea ​​level rise and fromrising tides.

Dr. Graham said his team cannot make 100 percent certain predictions, nor estimate when the glacial structure could completely dissolve. The only certainty is that the reduction of CO2 emissions on the planet in the next 75 years will be crucial for its survival.

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