A new study has disclosed that the Earth’s inner core has stopped spinning and has changed its spin orientation in the opposite direction. The study was published in the scientific journal, Nature Geoscience.
The globally consistent pattern indicates the inner-core rotation halted in 2009 and surprisingly altered in the opposite direction.
Researchers, from China’s Peaking University, are of the view that the inner core rotates back and forth, like a swing, suiting the Earth’s surface. They told the French news agency AFP, “One cycle of the swing is about seven decades, meaning it changes direction roughly every 35 years. It previously changed direction in the early 1970s, and predicted the next about-face would be in the mid-2040s.”
What is the Earth’s Inner Core?
The Earth’s core consists of three parts: the crust, mantle and core. The Earth’s inner core, 7000 kilometres wide, is made up of a shell of liquid iron within a solid iron centre.
The Earth’s inner core was discovered in 1936, while researchers were studying seismic waves from earthquakes that travel throughout the planet. The change in the waves revealed the Earth’s core.
Researchers from Peaking University studied the earthquakes that occurred between 1996 and 2021 which revealed that in 2009 the core stopped spinning and might be in the process of altering its spinning direction.
A 1996 study in Nature unveiled that the duration of the seismic waves that transverse the Earth’s inner core display a small yet systematic variation over the past three decades. These variations are due to the rotation of the inner core having a rotation rate of 1 degree a year faster than the daily rotation of the mantle and crust.
What now?
According to the researchers, the rotation of the core is linked to the changes in the length of the day. This causes small changes in the exact time the Earth takes to rotate on its axis.
The teams of researchers have said that examinations offer evidence for dynamic interactions between the Earth’s layers, from deep within the surface, due to gravitational coupling and angular momentum from the core and mantle to the surface.
“We hope our study can motivate some researchers to build and test models which treat the whole Earth as an integrated dynamic system”, the researchers said.
In addition, they stated that the change in the spinning has so far not yet produced any evidence indicating its effect on people’s lives on the planet’s surface.
