2024-07-08 16:43:14
Last year, scientists came up with the theory that the Earth’s core began to rotate against the movement of the Earth. They have now succeeded in confirming the hypothesis that the core changes its motion periodically every seventy years.
The core, which lies more than five thousand kilometers deep below the Earth’s surface, was spinning faster than the planet’s rotation in the 1970s. Its motion gradually slowed until the moment came when the core and the Earth were spinning at the same speed. In 2008, it was already rotating more slowly and currently it is even rotating in the opposite direction to the rest of the planet. The hypothesis, which was written about at the beginning of last year, has now been confirmed by American scientists.
“We’ve been arguing about this for 20 years, and now it’s finally settled,” said John Vidale, co-author of the study at the University of Southern California. “I think we’ve ended the debate about whether the inner core is moving and what its pattern has been over the last few decades,” he added to CNN.
Although the core rotates in regular cycles, the deceleration and acceleration do not always occur at the same time. Similarly, the speed with which it rotates in different directions varies. Scientists have not yet discovered why this happens. According to one theory, the metallic core, which cannot be directly examined, might not be as solid as everyone thought. The rotation could therefore deform it, which in turn would affect the speed of rotation.
Changing the rotation of the core does not change anything for people on Earth. This can affect the dispersion of seismic waves after an earthquake or the magnetic field, or shorten the days, but it is an imperceptible thousandth of a second per day. “I can’t imagine that it would be of much importance,” says study co-author Vidale.
What is the earth’s core
Planet Earth consists of several layers, the inner core furthest from the surface consists mainly of iron and nickel. The metal ball, discovered in 1936 by the Danish seismologist Inge Lehmann, has baffled scientists ever since, the New York Times recalls.
Experts believe that the core crystallized from a molten metal mixture sometime in Earth’s not-too-distant past after the planet’s interior had cooled sufficiently. Scientists can study the core and its changing motion based on earthquakes. When the ground starts to shake somewhere, they monitor where and how fast the tremors spread. Seismology was interested in the fact that equally strong earthquakes in the same place did not have the same impact on the surrounding world.