Earth's inner core has been "paused" and is now being reversed, according to new research.
The Earth's inner core is located deep inside and extends for about 746 miles, according to NASA. It is mostly made of pure, solid iron. Perhaps while previous research suggests that the inner core is rotating, a new insight suggests it may have "paused" its rotation and even reversed.
The Earth's magnetic field is caused by the liquid outer core that protects the inner core. According to Nature, the outer core also allows the inner core to rotate independently.
Scientists at Peking University in Beijing used this technique in their latest research, which was published Monday in the journal Nature Geoscience.
According to Yang and Song's investigation of seismic waves produced by similar earthquakes dating back to the 1960s, the inner core's rotation appears to have "paused" between 2009 and 2020, and may even be reversed "by a small amount."
This is a huge shock to you. It's probably not the first time our inner core has stopped. However, they now believe that the shift is "associated with a gradual turning-back of the inner core as part of an approximately seven-decade oscillation."
Yang and Song's findings suggest a "another overturn or a slowdown of the rotation in the early 1970s."
Variations in the speed at which seismic waves travel through the inner core are consistent with "a number of other geophysical observations," particularly the duration of day and the magnetic field, both of which are influenced by the movement of the inner core.
Although the changes are "valid," Yang and Song's conclusions may not reflect what's really happening deep within our planet. John Vidale, a professor of earth sciences at the University of Southern California who wasn't involved in the study, told The Wall Street Journal that there are "several competing theories" about the Earth's core.
These include suggestions that the inner core's rotation would be stopped in the early 2000s, and that it would be reversed more often than Yang and Song had predicted.
"No matter what you like, there's some data that doesn't," Vidale told The New York Times.
Vidale co-authored a paper revealing that the inner core's spin changed between 1969 and 1974, and that it appears to oscillate "a couple of kilometers every six years."