Strange changes to seismic waves deep under the planet could reveal unusual activity in the Earth’s core.
February 10, 2025
It’s not unusual for the Earth’s core to change its rate of rotation and even its shape over time – though not simultaneously. But new research reveals that something unexpected is happening under the radar.
For a long time, scientists have debated about the cause of strange changes to seismic waves, caused by earthquakes, when they ripple through the core. One camp argued it’s because of the rotation rate, while the other argument is that it’s the inner core’s shape deforming. In the new study, published in Nature Geoscience, scientists from China and the US reveal that it’s likely to be both.
The research shows that in 2010 the Earth’s inner core went from rotating faster to slower than the rest of the planet, which – along with changes near the surface of the inner core – likely interrupted the seismic waves. Like X-rays, these waves allow scientists to ‘see’ what’s happening inside the planet – so the researchers think the discovery could help us unlock more information about the core’s properties and structure.
“For now, these findings simply provide an observable change
