Produced by: Tarun Mishra Designed by: Manoj Kumar
Scientists from the University of Southern California (USC) have discovered that Earth’s inner core has been slowing down relative to the planet’s surface since around 2010.
The research, published in the journal Nature, resolves a long-standing debate about the movement of Earth’s innermost layer.
The inner core, a solid sphere composed of iron and nickel, plays a significant role in influencing the outer core’s convection patterns and Earth’s magnetic field.
Earth consists of four main layers: the solid inner core, the liquid outer core, the viscous mantle, and the thin solid crust.
Located over 4,500 kilometres beneath the surface and roughly the size of the moon, the inner core’s behaviour is studied through seismic waves from earthquakes and nuclear tests.
John Vidale, Dean’s Professor of Earth Sciences at USC, and his team analysed data from 121 repeating earthquakes and historical nuclear tests to study the inner core’s movement.
The team found consistent evidence of the inner core’s slowdown, marking the first such observation in many decades.
The slowdown is attributed to the churning of the liquid outer core, which generates Earth’s magnetic field, and gravitational influences from the mantle.
The USC scientists plan to further investigate the inner core’s behaviour and its implications for Earth’s magnetic field and rotational dynamics. This study not only settles a scientific debate but also opens new research avenues into Earth’s interior processes.