Earth’s inner core is ‘backtracking’ and it could have an impact on time

Humans backtrack all the time; attempting to get out of plans, promises or comments taken the wrong way, and now it seems the Earth itself is following our lead.

According to a study from the University of Southern California, researchers have found evidence that the Earth’s inner core is 'backtracking' - and it's been doing so for some time.

Since the Earth's inner core is hidden 3,000 miles under our feet, it can't be studied in person, meaning scientists typically have to analyze renderings of the inner core’s movement created using the seismic waves of earthquakes.

In this particular study, researchers looked at seismic data recorded around the South Sandwich Islands from 121 repeating earthquakes - earthquakes that occur at the same location - which occurred between 1991 and 2023, along with data from a number of nuclear tests.

The topic of movement of the inner core is one which has been debated by the scientific community for two decades, but the findings of the USC study determined that the core has, in fact, slowed down.

The Earth's core is hidden beneath our feet. (Getty Stock Photo)

John Vidale, Dean’s Professor of Earth Sciences at the USC Dornsife College of Letters, Arts and Sciences, commented: “When I first saw the seismograms that hinted at this change, I was stumped. But when we found two dozen more observations signaling the same pattern, the result was inescapable."

The research revealed that the inner core began to decrease its speed around 2010, and is considered now to be reversing in relation to the planet's surface.

For the first time in approximately 40 years, the inner core is moving slightly slower, instead of faster, than the Earth’s mantle.

More research is needed to learn why the core is slowing. (Getty Stock Photo)

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

Though the inner core isn't something we can see, the changes it's experiencing could impact time itself - although we probably won't notice it.

Vidale explained: “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.”

Following the initial research, the USC scientists hope to chart the trajectory of the inner core in even greater detail with goals to figure out exactly why it's changing.

“The dance of the inner core might be even more lively than we know so far,” Vidale concluded.