“Un cycle complet (one way then the other) of this swing is about seventy years old“, according to them. The last change of rotation before that of 2009 would have occurred in the early 1970s. The next would take place in the mid-2040s, completing the cycle, according to the Chinese researchers. This rotation would be more or less set on the day length changes, tiny variations in the exact time the Earth needs to rotate on its axis.
To date, there are few indications of an influence of this rotation on what happens on the earth’s surface. But the two authors are convinced that there are physical links between all the layers that make up the Earth. “We hope our research motivates researchers to design and test models that treat the Earth as an integrated dynamic system.“, they explain.
Independent experts welcomed this research with interest but also with some reserve. “This is a very careful study done by excellent scientists who used a lot of data“, John Vidale, seismologist at the University of Southern California, told AFP. But according to him, “none of the existing models really explains all the available data very well“.
John Vidale published a study last year suggesting that the inner core is oscillating much faster, changing direction about every six years, according to seismic data from two nuclear explosions dating back to the late 1960s and early 1960s. 1970. A tipping moment close to that indicated by the Chinese researchers’ study, “a coincidence”according to the American seismologist.