Researchers have discovered Earth’s inner core deformation. The core has changed shape over the past 20 years, altering previous scientific assumptions about its structure. Often imagined as a perfect sphere, the inner core appears to have deformed by more than 100 meters in some areas.
Professor John Vidale from the University of Southern California led the study published in Nature Geoscience. Earth’s core is the planet’s engine, generating a magnetic field shielding life from harmful solar radiation.
The inner core rotates independently of the outer core, and the rest of Earth keeps the planet habitable. Without this movement, Earth would lose its magnetic shield and resemble Mars, which became barren after its field disappeared billions of years ago.
Scientists believe Earth’s inner core deformation occurs where the solid inner core meets the scorching liquid outer core. Their research initially aimed to investigate why the inner core slowed down relative to Earth’s rotation before speeding up again in 2010.
Seismic wave analysis from repeated earthquakes between 1991 and 2023 revealed how the core’s shape has evolved. By studying how shockwaves travel through Earth, interior scientists can determine the composition and behavior of deep planetary layers.
The team found that gravitational forces and dynamic movement of molten iron in the outer core might be responsible for the inner core’s deformation. These findings could provide critical insights into Earth’s magnetic field, which has experienced irregular fluctuations in recent decades.
Australian National University’s Professor Hrvoje Tkalcic, who did not participate in the study, called the research an important step forward. He suggested that further exploration could improve estimates of key properties like the inner core’s viscosity, one of modern science’s least understood variables.
Over time, the outer core will continue freezing, turning into solid iron, but this process will take billions of years. Scientists warn that once the inner core fully solidifies, Earth will lose its magnetic protection, making life impossible. However, by that time, the Sun will likely have expanded, consuming the planet.
