The inner core of Earth may have changed shape in the past 20 years, BBC reports citing to a group of scientists.
The inner core is usually thought to be shaped like a ball, but its edges may actually have deformed by 100m or more in height in places, according to Prof John Vidale who led the research.
Earth's core is the beating heart of our planet as it produces a magnetic field that protects life from burning up in the Sun's radiation.
The inner core spins independently from the liquid outer core and from the rest of the planet. Without this motion, Earth would die and become more like barren Mars which lost its magnetic field billions of years ago.
The change in shape could be happening where the edge of the solid inner core touches the extremely hot liquid metal outer core.
The research is published in the scientific journal Nature Geoscience. The scientists were originally trying to find out why the inner core may have slowed down to a slower pace than Earth's rotation before speeding back up again in 2010.
Understanding how the Earth's core works is essential to understanding the magnetic field that protects the planet, and whether that could weaken or stop.
The inside of our planet is an extremely mysterious place. The core is about 4,000 miles from the Earth's surface and, despite best efforts, scientists have so far been unable to reach it.
So, to try to unlock its secrets, some researchers measure the shockwaves caused by earthquakes as they ripple through the planet.
The way the waves travel reveals what type of material they moved through, including in the inner core, and help to paint a picture of what lies beneath our feet.
The new analysis looked at seismic wave patterns from earthquakes that repeated in the same location between 1991 and 2023. That helped to show how the inner core is changing over time.
Prof Vidale, an earth scientist at the University of Southern California, found more evidence to back up the theory that during those years the inner core slowed down around 2010.
But his team also found the evidence of the inner core's changing shape.
