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Des chercheurs de l’université de Harvard (États-Unis) ont mesuré les déformations de la croûte terrestre dues à la fonte des glaces. Elles s’étendent au-delà de ce qu’ils avaient imaginé. © Fly_and_Dive, Adobe Stock

Melting ice distorts the earth!

When the ice caps melt, the crust is deformed. In a local way, the researchers thought until then. But satellite data is now questioning the idea. Over the past two decades, melting Arctic ice has caused significant deformation of the Earth’s crust over much of the Northern Hemisphere.

When the ice melts, the Crustal Below is located distorted. years of study ice peaks and the glaciers They have previously shown this to researchers. but today Harvard University team (US) notes that the affected area could extend further. Up to hundreds, if not thousands of kilometers of melting ice sheet.

The researchers worked on satellite data collected between 2003 and 2018. The data shows how ice in the Arctic has melted under the influence of Man-made global warming. How is the earth’s crust deformed? Thus they measured the horizontal displacement of the latter. In some areas, they also note that the Earth’s crust moves at a greater distance horizontally than vertically. On average, deformation is measured by several tenths of a millimeter per year. And that’s over much of the northern hemisphere.

To help us understand, Sophie Coulson, a geophysicist, suggests communicationMeaningful picture. “Imagine a plank of wood floating on the surface of the water, in bathtub. If you push the board down, the water below will also move down. If you remove the board after that, you will see that the water moves vertically to fill the remaining space. “

Effects that have not yet been clarified

When the ice melts, it changes the face of the Earth. Which is especially boring, because movements generated from the earth’s crust, in turn, can have an effect on Source ice. By adjusting the slope of the bedrock under the cover.

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Harvard researchers remember that what they observed today actually happened in the past. About 2.6 million years ago, a ice Age that covered Northern Europe and Scandinavia with ice. Until about 11,000 years ago. “The Earth is still jumping after the snow meltsSophie Coulson confirms. Earth acts a little like a very slow liquid. Ice age processes take a very long time to unfold, and so we can still see results today.. »

According to the researchers, the repercussions of these movements Crustal big. This study is the first to show that the recent loss in mass ice peaks Glaciers cause movement in space on Earth’s surface that Magnitude And the spatial extent is greater than those previously defined. It may now be possible to search for this signal in regional and larger scale navigation satellite systems datasets, in order to produce improved constraints, in principle, on ice mass distribution or structure fluctuations. solid in Earth.

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