Earth’s core is now rotating in reverse direction, slowing down: What does it mean?

Earth's composition is more complicated than we think and is changing continuously every day. The inner part of the planet can be divided into three different layers: crust, mantle, and core. Several theories suggest that Earth's core is rotating independently of our spinning planet. Latest research by scientists has revealed that the rotation speed of Earth's core is slowing down dramatically and has even reversed.  

Earth's core

Earth's core is the hottest part of the planet, equivalent to that of the Sun's surface. The core is buried around 5,180 kilometres deep inside the Earth and consists mainly of iron and nickel. The inner core is surrounded by a liquid metal outer core, which acts as a barrier with the rest of the Earth. This barrier allows Earth's core, akin to a hot solid ball of metal, to spin independently and not necessarily align with the rest of the planet.

Is the rotation speed of Earth's core slowing down?

Danish seismologist Inge Lehmann discovered the planet's inner core in 1936. Since then, scientists have continued to debate its rotation speed and direction. One reason scientists have limited evidence to prove their point is that it is impossible to observe or collect direct samples of Earth's deep interior. Most of the research and studies are based on variations between waves of similar strengths passed through the core at different times.

Data from seismograms from repeated earthquakes and explosions on Earth indicate that the rotation speed of the solid inner core has been constantly degrading compared to the Earth's surface over the past few years, according to a new finding published in the journal Nature in June this year. 

According to CNN, the research not only validates the Earth's slowdown but also supports scientists' claim, made in 2023, that the core's deceleration is part of a decades-long pattern of slowing down and speeding up.

The model, proposed in 2023, described the pattern of rotation speed and direction of Earth core. The model proposed that the inner core of the Earth had spun faster than Earth's crust in past, but was now spinning slower. For a while, core and the Earth's rotation matched. Later, the rotation speed of the Earth's core reduced even more until it started moving in reverse direction.