From where we live on the surface, we can only see about 0.5% of the planet. 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 the inner core of the Earth might have just stopped turning before suddenly changing direction.
Scientists believe there is nothing to worry about, despite the fact that it may appear to be the end of the world. According to Insider, scientists do not believe it will significantly alter life on Earth other than to confuse them.
Analysis of seismic waves from earthquakes that have passed through the Earth’s inner core along similar paths since the 1960s was used by Yi Yang, an associate research scientist, and Xiaodong Song, a chair professor at Peking University, to determine how quickly the inner core is spinning. On Monday, their findings were published in the Nature Geoscience journal.
According to John Vidale, a geophysicist at the University of Southern California, “It’s probably benign, but we don’t want to have things we don’t understand deep in the Earth.” Vidale made this statement to The Washington Post.
The Earth’s solid inner core may undergo rotational variations every few decades, according to peer-reviewed research.
Strong earthquakes and nuclear testing during the Cold War have caused seismic waves to reverberate throughout the Earth’s core, allowing scientists to infer details about its activities despite the fact that they cannot see the inner core directly.
The deep seismic waves have demonstrated that the core may rotate a little faster than the rest of the Earth. The core is primarily composed of pure, solid iron and nickel.
According to the study’s authors, “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.”
Waves move in different directions over time, which suggests that the core is also changing.
The seismic waves that occurred between the 1960s and the present are the focus of the new study. The researchers discovered a peculiarity in 2009: Trajectories of identical seismic waves have not changed over the past ten years. This suggests that at that point, the inner core may have stopped rotating.
CNN quoted Song as saying, “When you look at the decade between 1980 and 1990, you see clear change, but when you look at 2010 to 2020, you don’t see much change.”
Two pairs of nuclear explosions have yielded data suggesting that the inner core may pause and reverse its spin approximately once every seventy years.
One theory proposes that the Earth’s magnetic field pulls on the inner core, causing it to spin, while the mantle’s gravitational field acts as a counterforce. The iron ball’s spin may be affected by one factor over another every few decades.
It is challenging and requires guesswork to explain these seismic record anomalies given the limited knowledge of the inner core.
The idea that the inner core’s surface is changing over time rather than the entire iron ball is an alternative theory. In a 2006 paper, Stony Brook University seismologist Lianxing Wen first proposed and continues to advocate for this concept. He stated that would account for the breaks in 2009 and 1971.
The intriguing properties of the inner core and its interactions with the planet’s other layers may be better understood thanks to the new research.
According to the Insider report, Vidale and his colleagues will continue to listen to seismic waves that travel from one end of the world to the other and directly through the iron core.