Earth’s Inner Core Changing Shape? Check What New Study Has Revealed

New Delhi, India: New research suggests that Earth's solid inner core, a metal sphere deep inside the planet, could be experiencing significant changes in its rotation and surface structure. Seismic waves from earthquakes have revealed that the inner core's rotation may have slowed, paused, or even reversed relative to the Earth's surface about 15 years ago. This finding, presented by geophysicist John Vidale of the University of Southern California at the American Geophysical Union meeting, points to potential surface changes as well.

Since no instruments can directly reach Earth's inner core, scientists rely on seismic waves generated by earthquakes to study it. These waves travel through Earth's layers and are recorded by seismic stations across the globe. Researchers often analyze waves originating from the South Sandwich Islands near Antarctica, which travel through the Earth's core and are recorded in places like Alaska. Comparing waveforms from similar earthquakes over time has revealed subtle changes in the core.

Vidale and his team studied seismic data from about 200 earthquake pairs recorded between 1991 and 2024. They found differences in waveforms recorded at Yellowknife, Canada, but not at Fairbanks, Alaska. This suggests that the inner core’s surface may be deforming.  

The research proposes that the inner core might be subtly reshaping as a whole or that specific areas could be swelling or contracting. These changes could be caused by gravitational forces from the mantle or the flow of materials in the molten outer core.

While the inner core's dynamics remain mysterious, this research provides new insights into how Earth's deepest layers interact. Understanding these changes could improve our knowledge of Earth's evolution and its magnetic field, which is generated in the outer core and affects everything from navigation to protecting life from solar radiation.