The Earth’s inner core may have changed shape in the past 20 years, according to a team of scientists.
While it is thought to be spherical in shape, its edges may have been warped by 100 meters or more in places, according to Professor John Vidale, who led the study published on Monday in the journal Nature Geoscience.
The Earth’s core is the “heart” of our planet, producing a magnetic field that protects life from being scorched by the Sun’s radiation.
The inner core rotates independently of the liquid outer core and the rest of the planet. Without this movement, Earth would die and look more like a barren Mars that lost its magnetic field billions of years ago.
The change in shape can occur where the edge of the solid inner core touches the extremely hot liquid metal outer core.
How does the shape change?
Professor Vidale, a geoscientist at the University of Southern California, found more evidence to support the theory that the inner core slowed down during these years around 2010. But his team also found evidence of a change in the shape of the inner core.
This seems to happen at the boundary between the inner and outer cores, where the inner core is close to melting point. The flow of liquid in the outer core, as well as the pull of an uneven gravitational field, can cause the deformation.
Over time, the liquid outer core “freezes” into the solid inner core, but it will take billions of years for it to become completely solid. This would almost certainly mean the end of life on Earth, but by then the planet will likely have already been “devoured” by the Sun.
