Far below the Earth’s surface, 1000’s of kilometres beneath our feet, our planet’s core appears to be doing something a bit unusual.
The Earth’s inner core, an insanely hot iron ball roughly the dimensions of Pluto, appears to have stopped spinning, and researchers say it would even be spinning the opposite way.
Recent research published Monday within the Nature Geoscience journal analyzed seismic waves from repeating earthquakes during the last six many years and concluded that the core’s rotation stopped across the 12 months 2009 after which slowly restarted in the wrong way.
And while it’s largely unknown what impacts these directional changes have above the Earth’s surface, the study’s researchers say they’ll see a longtime pattern wherein the core, relative to the Earth’s surface, operates as a type of swing, changing direction roughly every 70 years.
“We expect that the core is, relative to the surface of the Earth, rotating in a single direction after which the opposite, like a swing,” Xiaodong Song and Yi Yang, the study authors at Peking University in China, told AFP.
In keeping with the researchers, the last rotation change before 2009 would have occurred within the early Nineteen Seventies, and the subsequent one will happen within the mid-2040s.
The Earth’s core is essentially mysterious. Due to its extreme depth below the planet’s surface, it’s difficult to check.
Nevertheless, probably the most recent data shows that parts of the core that previously showed signs of variation suddenly slowed down and showed little or no change around 2009. Notable changes were also present within the early Nineteen Seventies, suggesting that these pauses could be a part of an oscillating core.
In keeping with NASA, the liquid outer core that surrounds Earth’s inner core is liable for our planet’s magnetic field. Because the molten iron and nickel within the outer core move, electrical currents are established, leading to said magnetic field. The outer core also allows the inner core to spin by itself, Nature explains.
This oscillation isn’t cause for much concern, the study’s authors say, and there are scientists who warn that there are “competing ideas” about what’s happening within the Earth’s core.
John Vidale, a professor of earth sciences on the University of Southern California that wasn’t involved within the study, points out that various studies have resulted in competing data and there’s nobody theory that has been scientifically proven.
Yang and Song “identif(y) this recent 10-year period (that) has less activity than before, and I believe that’s probably reliable,” Vidale told Science News, but said that beyond that, the research is contentious.
Last 12 months, Vidale and a colleague reported findings that the inner core may reverse its rotation every three years or so, based on seismic waves from nuclear tests. And other researchers theorize that the core isn’t moving in any respect, but that the inner core has the ability to alter shape.
The Peking University researchers claim of their paper that this oscillation “coincides with changes in several other geophysical observations,” equivalent to the length of days, and changes to the Earth’s magnetic field.
“These observations provide evidence for dynamic interactions between the Earth’s layers, from the deepest interior to the surface, potentially as a result of gravitational coupling and the exchange of angular momentum from the core and mantle to the surface,” they write.
“We hope that our research motivates researchers to design and test models treating the Earth as an integrated dynamic system,” they explain.
© 2023 Global News, a division of Corus Entertainment Inc.