Earth’s solid metal core may no longer be spinning relative to the large mass of the surrounding planet, thanks to what appears to be a recent slowdown, according to the results of a new study.
At the heart of our planet is a gigantic ball of solid metal 2,400 km wide, surrounded by an outer core of superheated liquid iron and other materials.
This liquid barrier separates the solid inner core from the surrounding Earth’s vast mass, allowing it to spin independently. Scientists have long believed that the central core rotates significantly faster than the outer mantle and crust of our planet.
This phenomenon, known as the superspin, is thought to be partially responsible for the formation of the Earth’s protective magnetic field and may even have an effect on the temperature of the oceans and the earth. the length of each day.
But according to new research published in the journal Nature Geology, The speed of the core may have slowed significantly in recent years.
In the last study — Reported by Vice – a team of scientists analyzed data from seismic waves created by powerful earthquakes that pass through our planet’s crust and interact with the inner and outer core. These earthquakes mostly occurred in places spread around the world between 1995 and 2021.
Some geologists believe that the rotation of the central core affects the time it takes for seismic waves to travel across the planet, and to measure the rate of rotation of the Earth’s core by tracking changes in the speed of waves that are very close to each other. Previous research has used this technique to estimate that the huge metal ball rotates roughly one-tenth of a degree faster than the surrounding mantle each year.
However, Earth’s core may now have stopped spinning relative to the rest of the planet, according to the results of the new study. According to seismic data, the shift may have actually occurred in 2009 and the core may now be preparing to shift into a ‘period’ period.lower rotation‘, where our world will spin slower than the rest.
“There are two great forces acting on the inner core,” study authors Yi Yang and Xiaodong Song from Peking University told Motherboard. “One is the electromagnetic force. Earth’s magnetic field is produced by fluid motion in the outer core. The magnetic field acting on the metallic inner core is expected to rotate the inner core by electromagnetic coupling.
“The other is the force of gravity. The mantle and inner core are both highly heterogeneous, so gravity between their structures tends to drag the inner core into a position of gravitational equilibrium, called gravity coupling.
According to the researchers, imbalances in the two forces can cause the nucleus to speed up or slow down. To their surprise, the duo discovered that the core also appeared to have stopped spinning independently of the mantle in the early 1970s, suggesting that the core’s spin can naturally change over a 70-year cycle.
It’s worth noting, however, that not all scientists agree that the core is spinning faster than the rest of the Earth, and instead suggest that deviations in the travel time of seismic waves may instead be due to changes in the surface of the large metal core.
Yang and Song are now waiting for more earthquakes to send seismic waves through the core to further test their theory. NASA is also planning start a task Discovering what could be the exposed metal core of a shattered ancient planet that could shed light on the inner workings of Earth and the other worlds that populate our solar system.
Be sure Stay connected to IGN keep up to date with the biggest and most frustrating developments in science.
Anthony is a freelance writer for IGN that covers science and video game news. He has more than eight years of experience reporting groundbreaking developments in many scientific fields and has absolutely no time for your antics. Follow him on Twitter @BeardConGamer
Image Credit: Vadim Sadovski
