Register for the Wonder Theory Science newsletter from CNN. Explore the universe with news on fascinating discoveries, scientific progress and more.
Cnn
–
Scientists who have confirmed a few months ago that Interior nucleus of the earth Recently reversed its spin has a new revelation on the deepest secrets of our planet – they have identified changes in the shape of the inner nucleus.
The most interior layer of the earth is a hot and solid metal ball surrounded by an outer nucleus in liquid metal. For decades, planetary scientists suspected that the solid inner nucleus was distorted over time when it turned. Now, the researchers have found the first evidence of changing changes in the past 20 years in the form of the inner nucleus. Signs of the deformation of the nucleus appeared in waves of earthquakes which were strong enough to reach the center of the earth.
The research team used the same earthquake data for a 2024 study in order to resolve a long -standing debate on the rotation of the inner nucleus. They found that the inner nucleus once turned faster than the earth itself. But from 2010, the rhythm of the solid inner nucleus slowed down. It’s now turning backCompared to the rest of the planet.
Their new study, published Monday in the journal Nature geoscienceBases on this discovery, using earthquake data collected from 1991 to 2023. The previous work of scientists on the rotation of the nucleus helped them to interpret the variations in the height of seismic waves, defining them as indicators Changes on the surface of the inner nucleus, said Dr Dr..
“We can compare the signals that we see when the inner nucleus is returned to the same position as in another moment and see if there are differences that cannot be explained by rotation,” said Vidale, professor of Dean of Earth Sciences The Dornsife College of Letters, Arts and Sciences of the University of Southern California told CNN. The changes of form in the nucleus could contain clues to the forces deeply inside the earth which feed our magnetosphere, the invisible lines of magnetic energy which protect our planet from solar time and mortal radiation, reported the Researchers.
“The earth evolves on a geological time scale, therefore the observation of changes on an annual time scale is always intriguing, because it improves our understanding of the dynamics of the inner nucleus,” said Dr. Yoshi MiyazakiAssociate professor in the Department of Terre and Planetary Sciences at Rutgers University in New Jersey.
“Previous studies have already explained how the rotation of the inner nucleus has changed in the last decade, and this study presents a new perspective – non -rotary changes – adding another dimension to discussion. I believe that this will feed these debates more, “Miyazaki told CNN, who was not involved in the new research.
Of all the layers of the earth, the inner nucleus is the most distant and the most mysterious. This solid iron and nickel sphere has around 70% of the moon size, with a radius of around 759 miles (1,221 kilometers).
Temperatures in the inner nucleus are high at 9,800 degrees Fahrenheit (5,400 degrees Celsius), and pressures can reach up to 365 gigapascals (GPA) – more than 3 million times more than more than Average atmospheric pressure of the earth on earth. Although direct observation of the nucleus is impossible, scientists studied it by analyzing the changes in the size and shape of seismic waves when they cross the nucleus.
Earthquakes generate two types of waves. Primary waves, or P waves, are the first waves produced by an earthquake and move the soil in the same direction as the wave moves. The shear waves, or waves, are slower than the P and move the soil perpendicular to the direction of the wave.
The amplitude changes in a type of P wave penetrating the nucleus – the PKIKP waves – alluded to the deformations at the most shallow level of the inner nucleus, according to the new study. At the limit where the solid inner nucleus meets the liquid of the outer nucleus, the surface of the sphere could be more malleable than it is at deeper levels.
“It is almost science fiction to visualize what is happening on the surface of the inner nucleus,” said Vidale. “It is a place so different from our daily life, with different deadlines, different materials and incredible strengths. And yet, we can go there and learn more about this by simply passing some of the last observations. »»
Movement “Like landslides”
Scientists analyzed 168 quake paired waves in 42 locations near the southern sandwich islands, a chain of volcanic islands in the South Atlantic Ocean. The monitoring of the speed and the direction of the rotation of the nucleus gave the researchers a means of detecting changes in the form of the nucleus. Once they knew the speed of rotation of the nucleus, they could model its position, then compare different PKIKP waves which reached the nucleus when it was running in the same place.
According to the study, changes in amplitude in these paired waves could then be assigned to changes in the nucleus, rather than changing rotation. However, what this deformation of the inner nucleus could look like is more difficult to pin.
“Maybe the topography goes up and down. Maybe it slips like landslides, “said Vidale. “The most likely thing is that the outer core is simply to push the inner nucleus and move it a little.”
Although only one location in the inner heart has shown signs of deformation between 2004 and 2008, there may still be others that must be detected, researchers reported.
“It is difficult to know if we look at an abnormal or normal location,” said Vidale. “But a supposition would be that a certain deformation occurs quite often in many places.”
While the solid inner nucleus of the earth turns, the external fusion nucleus turns turning and tonnes. Their interactions generate magnetic energy, which takes place to wrap our planet in the magnetosphere. But the liquid external nucleus shrinks. Millimeter per millimeter, the inner nucleus has siphoned melted metal of the liquid nucleus which surrounds it, said vidal. It has probably taken billion years for the inner nucleus to cool down and solidify, and over the next billion years, the inner nucleus will continue to cool, sipping drops of liquid metal from the outer nucleus, until What the whole nucleus of the earth is a solid metallic sphere, he added.
“It will kill the magnetic field,” said Vidale. “There will be no more moving iron.”
However, such an event is billions of years in our future. And before this happens, the earth will probably be erased as our sun develops in a red giant and swallows the interior planets of the solar system, said vidal. Until then, scientists should have enough time to investigate the invisible functioning at the heart of our planet and discover what the internal rotation of the earth, the barattage and the form of form could hold in stores for the planet.
“With regard to the impact on life, as mentioned in the introduction of the document, the growth of the inner nucleus plays a crucial role in the generation of the Earth’s magnetic field, which protects us against harmful solar radiation”, said Miyazaki. “While a direct link between life on the surface of the earth and the ICB (central interior-tool border) remains distant, what is happening at the ICB still has implications for long-term evolution of the earth. ”
Mindy Weisberger is a scientific writer and media producer whose work has appeared in Live Science, Scientific American and How It Works Magazine.