Scientists have made a discovery in the mysterious core of the Earth

Earthquakes reveal secrets

Chinese researchers from Peking University believe they have found evidence that the rotation of the 1,300-kilometer-wide core has slowed slightly recently, and that the core may be about to start spinning in the opposite direction than it did. do in previous decades.

The researchers came to this conclusion by analyzing the travel time of seismic waves from different earthquakes, which have penetrated the deeper layers and exited the other side over the past six decades.

According to the researchers, the waves revealed that the Earth’s inner core was spinning slightly faster than the Earth’s mantle and surface until 2009. After that, the core appears to have slowed down a bit, keeping up with the rotation of the mantle and surface. on Earth’s surface, and now think they may be headed in the opposite direction.

Researchers: “This is not the first time”

According to the research group, this isn’t the first time Iron Man has taken a short break.

In the early 1970s, they also noticed a strange shift in seismic waves, suggesting that the slowdown may be part of a pattern in which the inner core–about every seven decades–starts to warp in the opposite direction.

Join the journey: the Earth’s interior hides a cake of extremes

Many different theories

Spinning in Earth’s innermost core is, to say the least, a hot scientific topic, and it’s not the first time that researchers have presented new theories about the motion of the hot iron mass. In 2004, researchers relied on Columbia University For example, the conclusion that the core rotates faster than the surface of the Earth itself. In 2011, researchers then discovered that it curls up much slower than we previously thought.

And in 2021, geophysicists looked at University of Southern California that the inner core moved in a six-year cycle in one direction and a six-year cycle in the other.

We know more about the sun.

The New Seventy Year Theory faces doubts from several quarters. But it is not so strange, because the theories are many and different. This is explained by Chris Finley, DTU Space Professor in the Department of Geomagnetism and Terrestrial Space.

He himself was not involved in the new study, but researchers of the Earth’s magnetic field, and he had previously used data from satellites to examine the Earth’s interior.

“The innermost core is the part of the Earth that we know the least about – we actually know more about the Sun than we do about what’s going on deep inside the Earth. The reason is that there are 5,000 kilometers of rock and liquid metal between us and so it’s very difficult to investigate.”

Such as diagnosis without direct samples

The long, impassable distance means that we rely on indirect observations — such as seismic waves or changes in the Earth’s magnetic field — like examining disease inside the body without taking any direct samples from it. Therefore, he doesn’t think the new study should be seen as a definitive conclusion to what’s going on there.

“This study is part of a process by which we try to learn more about this hidden place on our planet. But there will be a lot more to this story – it’s not the end,” he explains.

The question then becomes why should we be concerned at all with what is happening in a sweltering room many thousands of kilometers away under our feet? We should, according to the professor, because it could tell us something about what happens to our natural shield against radiation from space – the Earth’s magnetic field.

“It is the motions of the liquid part of the core, which are in opposition to the solid inner core, that generate our magnetic field. The liquid part is like a hot sea of ​​metal, the turbulent motions of which tug with the inner core. The two parts of the core are a kind of companion and thus rotate in the innermost core And when it relates to what’s going on with our magnetic field,” he explains.