Earth’s inner core is slowing down

Researchers at USC and Cornell Engineering have confirmed that the Earth’s inner core is now rotating slower than the planet’s surface for the first time in 40 years.

This movement is part of a 70-year cycle driven by a constant gravitational tug-of-war between the solid inner core and the rocky mantle. Magnetic forces from the liquid outer core push the inner core, while the mantle pulls in the opposite direction. These opposing forces cause the core to shift back and forth, creating shorter 6-year oscillations that match observations recorded in 2022. This internal drag affects the planet's overall rotation, leading to minor fluctuations in the length of a day of approximately ±0.2 seconds.

Unlike the previous 40 years where the core consistently outpaced the surface, it is now effectively backtracking. These findings, published in Nature, provide new data on how geodynamic interactions within our planet influence global timekeeping.

#science #geology #earth

Subscribe