Researchers studying decades of earthquake data say they have found the first evidence that, in addition to spinning backward, Earth’s inner core in changing shape.

New study reveals that Earth's inner core is undergoing unexpected structural changes, challenging long-held assumptions about its solidity.

The inner core of Earth may have changed shape in the past 20 years, according 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.

The planet’s inner core was previously thought of as a hard, solid sphere. But a new study has found that its edges are softer than realized and actually changing shape.