More than 2,200 kilometers beneath our feet, where molten iron and nickel boil in a permanent magma, a real upheaval has just been brought to light. In 2010, a portion of the outer core of our planet simply decided to turn around. While this sea of molten metal had been flowing westward for decades, it suddenly reversed its trajectory to head east again.
To understand the scale of the phenomenon, we must imagine the earth’s core as the heart of a gigantic dynamo. It is the constant movement of these liquid metals which generates our magnetic field, this invisible but vital bubble which protects us from cosmic radiation and the anger of the Sun. Suffice it to say that when the planet’s engine begins to hiccup or change direction, geophysicists around the world hold their breath and take a close interest.
The alert was given by a team of researchers led by Frederik Dahl Madsen, doctoral student at the University of Edinburgh. In a study published by the specialized journal Journal of Studies of Earth’s Deep Interior, relayed by New Atlas, scientists cross-referenced nearly thirty years of geomagnetic data collected between 1997 and 2025. Thanks to the ultra-precise eyes of several satellites, notably the Swarm and Cryosat missions of the European Space Agency (ESA), they were able to reconstruct the film of this incredible about-face.
According to their models, the great change of direction would have occurred around 2010, located precisely under the equator, in the middle of the Pacific Ocean. Researchers have also noted that this reverse current has already started to run out of steam since 2020. A temporary twist, but one that says a lot about the secret life of our depths. “Large-scale flow reversal beneath the Pacific raises new questions about the behavior of Earth’s deep interior»explains Frederik Dahl Madsen.
A cosmic dance beneath our feet
But then, what could have pushed this immense mass of liquid iron to change direction? Scientists point to even deeper events, nestled at the very heart of the Earth’s seed, the solid inner core. By analyzing the seismic tremors and magnetic waves that appeared on the surface of the core during this period, they understood that the different layers of the Earth influence each other in a sort of gravitational and magnetic standoff.
This discovery shakes up the vision of an immutable and stable internal core and shows that the bowels of the Earth are subject to cycles, oscillations and turbulences that are much more dynamic than previously thought. This is great news for scientists looking to anticipate the mood swings of our magnetosphere.
For the moment, don’t panic, our compasses will not lose their heads straight away and this reversed flow under the Pacific seems to be a short-term fluctuation rather than a definitive upheaval of the planet. Scientists do not yet know whether this is a regular cycle that repeats every twenty or thirty years, or something else.
The rest of the story will be written thanks to continued satellite observations. “Scientists now want to understand whether this is a short-term fluctuation or a repetitive oscillation»concludes Frederik Dahl Madsen.
