It’s Confirmed: The Earth’s Core is Rotating at a Slower Rate than the Rest of the Planet

The Earth’s core has been once again confirmed to be rotating slower than the upper layers of the planet, according to a new study that has independently come to the same conclusion as researchers with China’s SinoProbe Lab at Peking University arrived at last year. While the core’s rotation is only lagging behind by a fraction of a second each day, this development could have an effect on the length of the day for us surface-dwellers, as well as the generation of the planet’s magnetic field.

“When I first saw the seismograms that hinted at this change, I was stumped,” remarked John Vidale, an Earth scientist from the University of Southern California (USC). “But when we found two dozen more observations signaling the same pattern, the result was inescapable.

“The inner core had slowed down for the first time in many decades,” Vidale continued. “Other scientists have recently argued for similar and different models, but our latest study provides the most convincing resolution.”

The current slowing of the core’s rotation appears to have started sometime around 2010, following a period of “super-rotation” between 2003 and 2008 where the core was outpacing the upper layers. These changes in relative rotation of the solid inner core appear to be caused by the turbulent nature of the fluid outer core, wherein massive eddies act like gigantic dynamos that generate the planet’s magnetic field.

Although it is unknown as to whether or not changes in the core’s rotation will affect the magnetosphere, it could cause the upper layers to slow their rotation, although at such a slow rate that we’d never notice.

“It’s very hard to notice, on the order of a thousandth of a second, almost lost in the noise of the churning oceans and atmosphere,” Vidale explained.