Our Earth’s core consists of a solid inner core and a liquid outer core, which is largely composed of metals such as iron and nickel. The existence of this solid inner core was first proven more than ten years ago by Dutch geophysicist Arwen Dieus of Utrecht University.
Since then, scientists from all over the world have studied this mineral ball. From one The research was published in the scientific journal in June 2024 nature It now appears that the Earth’s inner core has been rotating more slowly since 2010, slower than the Earth’s mantle.
Seismic measurement
The Earth’s inner core has been a topic of debate for many years. One question is: How fast does the nucleus rotate? Since the inner core is about six thousand kilometers from the Earth’s surface, scientists cannot simply travel there to conduct research. Instead, they look at the seismic waves of earthquakes to better map the Earth’s composition.
How does this work? Earthquakes cause distorting vibrations because the Earth is not a homogeneous mass, but rather consists of different compositions. Depending on the speed and damping of vibrations, the temperature and materials can be determined, among other things.
In the new study, a team of scientists from the University of Southern California looked at measurements of 121 repeating earthquakes between 1991 and 2023 around the South Sandwich Islands in the Atlantic Ocean. By analyzing PKJKP waves (waves found only in solid materials), the research team concluded that the inner core has slowed by two to three times since 2010.
It is the first time in forty years that the inner core has rotated at a lower speed than the Earth’s mantle – perhaps due to the constant motion of the liquid outer core or due to the pull of gravitational forces.
What are the consequences?
We are unlikely to achieve anything by slowing down the inner core. The length of a day may change by only a thousandth of a second. Moreover, previous studies have been published on the rotation speed of the inner core.
like him Chinese seismologists suggested early 2023 The Earth’s inner core will no longer rotate in the same direction as the Earth, but is now starting to rotate in the opposite direction. According to researchers from Peking University, the inner core stopped rotating in 2009 and then changed its rotation direction. Future research will have to map more of Earth’s interior and answer questions about what’s happening six thousand kilometers below our feet.
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Esme van Dijk is the editor of National Geographic, Historia, and Traveler. Because of her love for history and culture, she prefers to travel around the world both physically and mentally. At the top of her wish list is a tour of Taiwan, Japan and South Korea, where she hopes to finally see her favorite artists in real life.
“Total coffee specialist. Hardcore reader. Incurable music scholar. Web guru. Freelance troublemaker. Problem solver. Travel trailblazer.”
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