Earth's inner core may have stopped spinning and could start spinning in reverse, reveals new study

Our planet Earth is constantly changing, moving and going through several phases whether by natural or human-made causes. A new shocking discovery has led scientists to believe that the rotation of Earth's deep core may have halted or perhaps reversed, per CNN. The crust, mantle, and inner and outer cores make up the Earth. The solid inner core is located around 3,200 miles beneath the Earth's crust and is separated from the semi-solid mantle by the liquid outer core. The inner core can hence revolve at a pace different from the Earth's rotation. 

Earth's core, with a radius of over 2,200 miles, is largely composed of iron and nickel and accounts for around one-third of the Earth's mass. Yi Yang, an associate research scientist at Peking University, and Xiaodong Song, chair professor at Peking University, investigated seismic waves from earthquakes that went through the Earth's inner core along identical routes since the 1960s. They wanted to determine how quickly the inner core is spinning. They said that what they discovered is surprising. Seismic data, which had previously altered over time, have shown minimal variation since 2009; it indicates that the inner core revolution has come to a halt.

They wrote in the study, "We show surprising observations that indicate the inner core has nearly ceased its rotation in the recent decade and may be experiencing a turning-back." Song added, "When you look at the decade between 1980 and 1990 you see clear change but when you see 2010 to 2020 you don’t see much change." The magnetic field created in the outer core drives the spin of the inner core, which is balanced by the gravity influences of the mantle. 

According to Hrvoje Tkalcic, a geophysicist at Australian National University who was not a part of the study, the speed of this rotation, and whether it fluctuates, is debatable. He said, "The inner core doesn’t come to a full stop." Moreover, he concluded that this study's finding means that the inner core was spinning a bit faster a decade ago because it was less in sync with the rest of the planet. "Nothing cataclysmic is happening," he reassured everyone. 

According to Song and Yang's calculations, a little imbalance in electromagnetic and gravitational forces might halt or even reverse the rotation of the inner core. They believe this is part of a seven-decade cycle. The turning point prior to the one they found in their data around 2009/2010 happened in the 1970s. The study's "data analysis is sound," according to Tkalcic. He also said that more "data and innovative methods" are needed to shed light on this problem and the current findings should be treated cautiously. Song and Yang agreed that more investigation is required.

Tkalcic has devoted an entire chapter to the inner core rotation in his work, "The Earth's Inner Core: Revealed by Observational Seismology." He suggests that the inner core rotates every 20 to 30 years, rather than 70 years as stated in the newest research by Yang and Song.