The Earths inner core could be slowing its spinbut dont panic

Date:
Tue, 24 Jan 2023 16:00:00 +0000

Description:
The planet's innermost core has a rhythm of its own. NASA We could be in the middle of a big shift in how the center of the Earth rotates. The post The Earths inner core could be slowing its spinbut dont panic appeared first on Popular Science .

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The planet's innermost core has a rhythm of its own. NASA

In elementary school science class, we learned that the Earth has three main layers: the crust, mantle, and the core . In reality, the corewhich is over 4,000 miles wide has two layers: a liquid outer core and a solid and dense inner core made mostly of iron that actually rotates.

A study published January 23 in the journal Nature Geoscience finds that this rotation may have paused recentlyand could possibly be reversing. The team from Peking University in China believe that these findings could indicate that the changes in the rotation occur on a decadal scale and are helping us understand more about how whats going on deep beneath the Earth affects the surface.

[Related: A rare gas is leaking from Earths core. Could it be a clue to the planets creation? ]

The Earths inner core is separated from the rest of the solid Earth by its liquid outer core, so it rotates at a different pace and direction than the planet itself. A magnetic field created by the outer core generates the spin and the mantles gravitational effects balance it out. Understanding how the inner core rotates could shed light on how all of the Earths layers interact.

In this study , seismologists Yi Yang and Xiaodong Song looked at seismic waves. They analyzed the difference in the waveform and travel time of the waves created during near-identical earthquakes that have passed along
similar paths through the Earths inner core since the 1960s. They
particularly studied the earthquakes that struck between 1995 and 2021.

Before 2009, the inner core appeared to be rotating slightly faster than the surface and mantle, but the rotation began slowing down and paused around 2009. Looking down at the core now wouldnt reveal any spinning since the
inner core and surface are spinning at roughly the same rate.

That means its not a steady rotation as was originally reported some 20 years ago, but its actually more complicated, Bruce Buffett , a professor of earth and planetary science at the University of California, Berkeley, told the New Scientist .

[Related: Scientists wielded giant lasers to simulate an exoplanets
super-hot core .]

Additionally, the team believes that this could be associated with a reversal of the inner core rotation on a seven-decade schedule. They believe that a previous turning point occurred in the early 1970s and say that this
variation does correlate with small changes in geophysical observations at
the Earths surface, such as the length of a day or changes in magnetic
fields.

The authors conclude that this fluctuation in the inner cores rotation that coincides with some periodic changes in the Earths surface system, demonstrates the interactions occurring between Earths different layers.

However, scientists are debating the speed of the rotation and whether it varies. This new theory is just one of several models explaining the
rotation. Its weird that theres a solid iron ball kind of floating in the middle of the Earth, John Vidale, a seismologist at the University of
Southern California who was not involved with the study, told The New York Times . No matter which model you like, theres some data that disagrees with it.

Since studying the inner core is very difficult and physically going there is almost impossible (unless youre famed sci-fi author Jules Verne ), whats really going on in the Earths core could always remain a mystery.

The post The Earths inner core could be slowing its spinbut dont panic appeared first on Popular Science . Articles may contain affiliate links
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Link to news story:
https://www.popsci.com/science/earth-core-spin/


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