Emily Chan
Finally, the inner core is located at the center of our planet. It is a super hot, solid ball of nickel and iron that has a radius of approximately 760 miles, which is about the same size as Earth’s moon. It’s not an object that is easy to study by any means.
To study the activity of the inner core, scientists must analyze the seismic waves of earthquakes. In this study, researchers from the University of Southern California examined data from 121 repeating earthquakes that occurred near the South Sandwich Islands in the South Atlantic Ocean between 1991 and 2023. They also looked at data from several nuclear tests.
By measuring how the seismic waves speed up and slow down, they can estimate the inner core’s position and movement.
The researchers discovered that the rotation of the inner core was slowing down due to the churning of liquid in the outer core and gravitational pulling from the mantle.
As a result, the length of our days may change, but not to worry—it would only be by fractions of a second. The difference would be almost undetectable, so there’s no need to reset your watches.
The researchers hope to be able to drill down further into the core to find out more about why it is slowing and how it will affect our planet.
The study was published in the journal Nature.
