Earth's Inner Core Has Deformed

Scientists have for some time suspected climate change is affecting Earth's beating heart. Now, a study offers specifics on changes at the planet's unreachable inner core. Building on 2024 research that described how the solid ball of iron and nickel at the center of the Earth, about 70% of the size of the moon, slowed its spin around 2010 and then started revolving backward compared to the rest of the planet, the latest study offers evidence of non-rotational changes to the inner core over the past 20 years, based on earthquake data. That data indicates deformations of up to 325 feet in the inner core's shallowest level, where the solid inner core meets the liquid metal outer core, per the BBC.

Though "it's almost science fiction to visualize what's happening on the surface of the inner core," some 4,000 miles from the Earth's surface, core-penetrating seismic waves offer clues, John Vidale, a professor of geophysics at the University of Southern California, tells CNN. "We can get down there and learn more about it by just sifting through some of the latest observations." Having figured out the inner core's rotation speed, researchers modeled the core's position as seismic waves repeated in the same location between 1991 and 2023, determining alterations in shape based on amplitude changes. They found signs the core's edges deformed in one particular location between 2004 and 2008.

"But one guess would be that some amount of deformation is happening fairly often in many places," Vidale, lead author of the study published Monday in Nature Geoscience, tells CNN. "Maybe the topography is going up and down. Maybe it's sloughing around like landslides. The most likely thing is the outer core is just pushing on the inner core and moving it around a little bit." Though this finding likely "doesn't affect our daily lives one iota," Vidale tells the BBC, understanding the interactions between the inner and outer cores is crucial to understanding Earth's magnetic field, which protects the planet from harmful solar radiation and cosmic rays. Without that field, "Earth would die," the BBC notes, though that's unlikely to happen for billions of years. (More discoveries stories.)