The river of molten iron flowing 1,400 miles below the Pacific Ocean in Earth’s outer core has surprised scientists by changing direction.
The observation provides new insights into the behaviour of the liquid outer core, which plays a key role in generating Earth’s magnetic field. Without this magnetic shield, the planet would be dangerously exposed to solar radiation.
Researchers at the University of Edinburgh checked ground observations and satellite data between 1997 and 2025. They report in The Journal of Studies of Earth’s Deep Interior, that in 2010, a broad region of iron-rich fluid beneath the equatorial Pacific switched from moving weakly westwards to strongly eastwards.
This video shows the large-scale flow in the molten core between 1997 and 2025
Lead author of the study, Frederik Dahl Madsen, at the University’s School of Geosciences, said: “The large-scale flow reversal beneath the Pacific raises new questions about the behaviour of Earth’s deep interior.
