Earth's hot core suddenly “went in reverse” after 2010 / ESA/AOES Medialab
Deep beneath the Earth's surface, scientists have detected an unusual phenomenon: a portion of the molten outer core suddenly changed direction. The anomaly occurred under the Pacific Ocean and was accompanied by other global changes that forced scientists to reconsider their understanding of the dynamics of the Earth's interior.
An international team of researchers analyzed nearly three decades of satellite observations of Earth's magnetic field—from 1997 to 2025—and discovered an unexpected change in the motion of the planet's outer core, a giant layer of hot liquid iron that surrounds the solid inner core and plays a key role in shaping Earth's magnetic field, ScienceAlert reports.
What is happening inside the Earth?
Normally, the flow of matter in the outer core moves predominantly in a westerly direction. This movement is the basis of the so-called geodynamo, the mechanism that creates the planet's magnetic field. It protects the Earth from cosmic radiation and helps preserve the atmosphere.
The scientists emphasize in a study published in the Journal of Studies of Earth's Deep Interior that this is not a local vortex or a small disturbance. The anomaly covered about 5% of the surface flow of the Earth's outer core. Moreover, the structure of the phenomenon resembled a large wave, and not the usual circulation bands that can be observed on gas giants like Jupiter or Saturn.
A large-scale change in the direction of the flow under the Pacific Ocean raises new questions about the behavior of the Earth's deep layers,
– said geophysicist Frederik Dahl Madsen from the University of Edinburgh.
According to him, scientists are now trying to figure out whether this was a short-term deviation, part of cyclical oscillations, or a new stable state of core circulation.
Changes in the flows of the Earth's molten core in 1997 – 2025 – watch the video:
How did this affect the planet?
The reason for this sudden “turn” remains unknown. However, scientists have noticed that other strange phenomena occurred around the same time, which may be related to the activity of the core.
One of them is the change in the length of the Earth's day. Approximately every 5.8 years, the speed of Earth's rotation changes slightly, and this cycle is associated with processes in the core. In 2010, the cycle suffered a noticeable failure, which lasted until 2014.
Seismic observations have also hinted at changes in the behavior of the inner core. And in 2017, ESA's Swarm satellites recorded a series of so-called “geomagnetic jerks” – sharp disruptions in the Earth's magnetic field, which are thought to be the result of turbulence in the planet's interior.
This study raises intriguing questions about how the Earth's deepest layers dynamically interact,
– said Swarm mission participant Elizabeth Yorfida.
According to the scientist, modern satellite missions allow us to observe processes inside the planet in ever greater detail, and it is now becoming clear that the Earth's core may be much more variable and complex than previously thought.
Researchers emphasize that these processes do not pose a direct threat to humans. However, a better understanding of the geodynamo's operation will help to more accurately predict changes in the Earth's magnetic field and the impact of space weather on satellites, navigation, and energy systems.