Is the Earth's inner core rotating backwards?

Is the Earth's inner core rotating backwards? We can only see about 0.5% of the earth from where we live on the surface. The solid iron core, which lies deep beneath the crust, heated rock mantle, and liquified outer core, is one of our planet's greatest mysteries.

A new study suggests that the iron ball that makes up Earth's inner core may have simply stopped rotating before abruptly changing direction.

Though it may appear to be the end of the world, scientists believe there is nothing to worry about. Other than confusing them, scientists do not believe it will have a significant impact on life on Earth, according to Insider.

Yi Yang, an associate research scientist at Peking University, and Xiaodong Song, chair professor at Peking University, calculated the speed of the Earth's inner core by analysing seismic waves from earthquakes that passed through it along comparable paths since the 1960s. Their findings were published in the journal Nature Geoscience on Monday.

"It's probably benign, but we don't want things deep in the Earth that we don't understand," John Vidale, a geophysicist at the University of Southern California, told The Washington Post.

According to peer-reviewed research, the rotational variations of the Earth's solid inner core may occur every few decades.

Although scientists cannot directly observe the inner core, they can infer information about its activities from strong earthquakes and Cold War nuclear testing that caused seismic waves to reverberate throughout the Earth's core.

The core is primarily composed of pure, solid iron and nickel, and deep seismic waves indicate that it rotates slightly faster than the rest of the Earth.

"We show surprising observations that suggest the inner core has nearly ceased its rotation in the last decade and may be experiencing a reversal," the study's authors wrote.

The direction of the waves shifts over time, implying that the core is also shifting.

The new research looks closely at seismic waves that occurred between the 1960s and the present. Beginning in 2009, the researchers discovered an anomaly: identical seismic wave trajectories remained unchanged over the previous ten years. That implies that the inner core may have ceased to rotate at that time.

"When you look at the decade between 1980 and 1990, you see clear change, but when you look at 2010 to 2020, there isn't much change," Song told CNN.

According to data from two pairs of nuclear explosions, the inner core may pause and reverse its spin every 70 years.

According to one theory, the gravitational field of the mantle acts as a counterforce, dragging on the inner core while the Earth's magnetic field pulls and spins it. Every few decades, one factor may outweigh another, influencing how the iron ball spins.

Given our limited knowledge of the inner core, explaining these anomalies in the seismic record is difficult and requires guesswork.

Another theory holds that, rather than the entire iron ball rotating, the surface of the inner core evolves over time. Stony Brook University seismologist Lianxing Wen first explored this idea in a 2006 publication and continues to support it today. That would account for the gaps in 1971 and 2009, he claims.

The new study could help scientists better understand the inner core's enigmatic properties and interactions with the planet's other layers.

Vidale and his colleagues will continue to listen to seismic waves that pass directly through the iron core and travel from one side of the globe to the other for as long as they can, according to the Insider report.