Has the Earth’s core stopped?

Madrid. The inner core of the Earth is the most inaccessible place on our planet, with extreme conditions: its temperature is higher than the surface of the Sun. It is a solid ball of iron and nickel that spins like any other. Land layers. Is it dead? The answer is no.

However, its speed has slowed down and it is “out of balance” with the rotational speed of the other planet -at least-.

So at least says a recent paper published in the journal Nature Geoscience led by Xiaodong Song and Yi Yang from Peking University. Although the scientists in the study say there was a “recent stop” and that the core’s rotation may have been “reversed,” this does not mean it has suddenly stopped or is spinning in the opposite direction to the Earth’s surface.

There are nuances, one of which is about relative speed (with respect to another object) and reversal of direction, explains Maurizio Matezzini, professor of geophysics at the Complutense University of Madrid and researcher at the Institute of Earth Physics. , EFE. For Geosciences (IGEO), from the Center for Scientific Research (CSIC), “Exploring the inner core is important for understanding the dynamics of the planet and its state of health.”

What is Inner Core?

The Earth is made up of different layers and at the center, 5,000 kilometers deep, is a sphere made almost entirely of iron. It has an inner core with a radius of 1,220 kilometers – slightly larger than Pluto and is surrounded by a similar composition 2,260 kilometers thick, but in a molten state, a kind of “mattress”.

The inner core was discovered in 1936 by Danish seismologist Inge Lehmann while analyzing seismic waves.

Convective motions in the liquid outer core, along with terrestrial circulation, create a magnetic field that shields Earth from the sun and from—highly energetic—particles from space.Alberto Molina, Marina Puente and Pablo Rivera from IGEO explain in the gallery.

Around the center is the mantle, about 2,900 kilometers thick, above which is the Earth’s crust.

How is the embryo examined?

The deep layer of the earth is difficult to analyze. Collecting samples by drilling is impossible, says Mattesini, who recalls that the deepest hole made to date is less than 12 kilometers.

Computed tomography still has technical limitations, so the alternative is seismic.

Earthquakes create seismic waves that travel through the planet’s interior and some pass through the inner core, radiating to the Earth’s surface. This is when seismographs record a signal containing information from the Earth’s core.

It takes approximately 24 hours for the planet to rotate and complete one revolution. Until now it was thought that the inner core, which rotates slightly faster than the mantle and crust, is moving forward by a factor of one-tenth, in the same dynamics recorded in the last decade. A grade every year.

Scientific controversy

The first investigation to talk about super-rotation comes from 1996 -singing is also involved-, but later studies say the opposite (there’s even a minority that says no differences in rotation). Adequate data exist, but the differences are so subtle that they leave room for interpretation and scientific debate.

What does a recent Nature Geoscience study conclude? The core, as of 2009, has the same rotational speed as the outer layers or slightly lower.

These differences in relative speed are very small, IGEO scientists explain in their forum.

For example, a car at 120 kilometers per hour is ahead of another at 121. “Through the window we will see it overtake us little by little. If the other vehicle brakes and goes at 120 kilometers per hour, we will see it go ‘still’ next to our car, even though it is moving as fast as we are”.

In the same way, the core will slow down and now, the mantle and the crust will rotate at the same speed, and it will be seen to stop from the surface of the earth.

Thanks to the geological record, IGEO explains on Twitter, the geological past years had longer days, meaning the Earth rotated faster, so the days were shorter (in the Mesozoic they were 23 hours long).

This is because the Moon is moving away from us at a rate of 3.82 centimeters per year and the effect slows down its rotation, imperceptible on a human scale.

A new study has found that the moon’s deceleration rate has experienced unusual values. It was observed that this could be due to the divergent rotation of the nucleus, by the propagation of seismic waves from earthquakes.

This is not the first time

This small change in core rotation is not the first time this has happened; The data shows another similar phenomenon in 1970.

It suggests that This phenomenon repeats itself for about 2-3 and up to 7 decades (depends on the author) and this same frequency appears in other geophysical observations such as the geomagnetic field, the duration of the day – thousandths of a second longer or shorter depending on the cycle – or the weather. They may be related.

But It’s just a hypothesis, warns Mattecini; No scientific evidence yet.

It’s clear that the actual time it takes Earth to complete one revolution varies quite a bit—which is important for adjusting navigation systems—and the days are now getting longer again. Continued investigation is necessary to uncover what lies behind this and the complex landscape dynamics.