Earth’s core has ‘reversed’ rotation. What does that mean for humanity?

As early as 2024, scientists from the United States and China discovered that the heart of the earth had slowed down and even stopped moving compared to the earthly crust. But so far, the general public – it is people like you and me – has barely noticed this remarkable change.

The kernel of the earth is made up of metals and, as its name suggests, constitutes the interior of the earth. It consists of a liquid outer core (in iron and nickel and other elements, which play a role in the magnetic field of the earth) and a Solid inner nucleus (also in iron and nickel, to a temperature up to 5,700 degrees Celsius).

The external nucleus of the earth begins at around 1,800 miles below the surface of the earth and the inner nucleus begins at around 3,200 miles below.

Changes in rotation in the heart of the earth

For a long time, scientists assumed that the inner nucleus of the earth had a stable, even and constant rotation under the earth’s crust. However, with the help of seismic analyzes (that is to say studies of earthquakes), the researchers discovered that this rotation is by no means constant but fluctuates. These fluctuations can be so massive that the kernel of the earth can move as quickly as the crust of the earth, then seems to be motionless.

However, this does not mean that the kernel of the earth turns in the opposite direction. Instead, it only appears in this way because it turns more slowly compared to the earthly crust – sometimes even much more slowly. The heart of the earth never remains stationary either, but simply ceases to change compared to the crust of the earth.

This current slowdown in the rotation of the terrestrial nucleus began in 2009. At that time, the nucleus and the crust of the earth moved more or less in unison, but since then, the movement of the Earth’s nucleus has become even slower. It seems that the heart of the earth changes its direction of rotation compared to the earthly crust every 35 years. Therefore, fluctuations that include an entire cycle last 70 years.

What effects does it have on earth?

Technically, the days can become longer or shorter due to changes in speed of rotation of the heart of the earth. However, the changes are tiny – in the range of milliseconds. We, humans do not notice it, but it can have an effect on astronomical measurements and satellites. Changes in the terrestrial magnetic field and climate are also possible.