The Earth's core would have changed its direction of rotation 'like a seesaw', according to these scientists


Author: Clark Tos
2023-01-24 14:01:04

This is a hot topic and a question that has been debated for decades within the scientific community: has the Earth's core changed its direction of rotation? Two Chinese scientists advance it.

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5000 kilometers below the surface of the Earth , the Earth's core would have started spinning upside down. This sphere made of iron and the size of Pluto does not cease to intrigue experts about it.

This Monday appeared in the magazine Nature Geoscience an interesting study. Xiaodong Song and Yi Yang of Peking University argue that the rotation from the Earth's core almost stopped around 2009 before starting off again in the opposite direction. We believe that the central core is, relative to the surface of the Earth, rotating in one direction and then in another, like a seesaw. “, they explain to AFP.

According to them, this change in rotation would be part of a cycle that would repeat itself every 70 years. ' A full cycle [back and forth] of this swing is about seventy years “, specify the two researchers. This phenomenon would be explained by the fact that this sphere floats in the liquid of the outer core. It would therefore be free to move, hence the change in rotation.

The scientific community refutes the theory

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The analysis revealed in Nature Geoscience by Chinese experts does not convince the entire scientific community. Many do not share this idea and remain skeptical. Some point in particular to the few available and effective tools to unlock the secrets of the Earth's core. To date, only the seismic analyzes passing through the center of the planet are used.

It is precisely on the basis of this lack of reliable tools that John Vidale, seismologist at the University of Southern California, refutes the theory of the Chinese researchers: “ This is a very careful study done by excellent scientists who used a lot of data , he told AFP. None of the existing models really explains all the available data very well. ».

According to Chinese researchers, the last change in the rotation of the nucleus took place in 2009, then before that, in the 1970s. rotation every six years.

Hrvoje Tkalcic, geophysicist at the Australian National University, evokes a cycle of 20 to 30 years and not 70 years like his Chinese colleagues. ' These mathematical models are probably all incorrect “, he admits because certain exploration tools have not yet been imagined to provide definitive answers on this theory. An endless debate dedicated to ' remain controversial ».

Source : TF1