25/01/2023
Far below the Earth’s surface, thousands of kilometres beneath our feet, our planet’s core seems to be doing something a bit unusual.
The Earth’s inner core, an insanely hot iron ball roughly the size of Pluto, appears to have stopped spinning, and researchers say it might even be spinning the other way.
New research published Monday in the Nature Geoscience journal analyzed seismic waves from repeating earthquakes over the last six decades and concluded that the core’s rotation stopped around the year 2009 and then slowly restarted in the opposite direction.
And while it’s largely unknown what impacts these directional changes have above the Earth’s surface, the study’s researchers say they can see an established pattern in which the core, relative to the Earth’s surface, operates as a sort of swing, changing direction approximately every 70 years.
“We think that the core is, relative to the surface of the Earth, rotating in one direction and then the other, like a swing,” Xiaodong Song and Yi Yang, the study authors at Peking University in China, told AFP.
According to the researchers, the last rotation change before 2009 would have occurred in the early 1970s, and the next one will take place in the mid-2040s.
The Earth’s core is largely mysterious. Because of its extreme depth below the planet’s surface, it’s difficult to study.
