Earth's core slowdown: USC scientists uncover surprising reversal
University of Southern California (USC) scientists have confirmed that the Earth's inner core has decreased its speed. This means that the inner core is now reversing its direction relative to the surface of the planet.
Researchers worldwide have been discussing the intriguing topic of the Earth's inner core movement for at least 20 years. Some previous findings suggested that it moves faster than the planet's surface. However, scientists from USC are now rejecting this thesis, publishing their research results in the journal "Nature." According to their findings, the Earth's core speed has been decreasing for over a decade.
Scientists were amazed by the new discovery
"When I first saw the seismograms indicating these changes, I was amazed," said John Vidale, professor of Earth sciences at USC. "But when we found two dozen additional observations showing the same pattern, the result was inevitable," he continued.
New research from the USA provides the most convincing findings to date. According to it, the Earth's inner core has slowed down for the first time in decades, as reported on the USC University portal.
The Earth's inner core is reversing relative to the planet's surface
The core in question, which is of interest to Earth scientists, is an iron-nickel sphere surrounded by a liquid iron and nickel core. It is comparable in size to the Moon and is located more than 8,000 kilometres deep within the Earth. It cannot be observed directly, making it a mystery to scientists. They must rely on data from seismic waves generated during earthquakes to simulate the inner core's movements.
In the latest research conducted by USC, data on wave shapes and recurring earthquakes were used to understand better what lies deep inside the Earth. Scientists collected data from 121 earthquakes that occurred between 1991 and 2023. They also considered data from Soviet nuclear tests conducted between 1971 and 1974.
Based on this data, the study reports that the decrease in the inner core's speed was caused by the swirling of the surrounding outer core with liquid iron. How does the knowledge that the movement inside the Earth has slowed down affect the Earth's surface and humanity?
Vidale responded that the reversal of the inner core could affect the length of the day. However, it won't be a noticeable difference. "It will be very difficult to notice. We're talking about a change on the order of one-thousandth of a second," the professor explains. He adds, however, that "the dance of the inner core may be even more lively than we previously thought."
Consequently, scientists from USC have announced that they will not stop studying the Earth's inner core and plan to conduct even more detailed observations to determine the core's trajectories. This will allow them to precisely determine why the outer surface of our planet currently moves faster than the core.
