Earth’s magnetic field is shifting, creating a massive, radiation-prone weak spot over the Atlantic.

Nature · Published 3 October 2026 Swipe more like this →

In short: A vast, weakening region in our planet's magnetic field is expanding rapidly, now covering a territory equivalent to nearly fifty percent of the European continent. This South Atlantic Anomaly forces satellites to endure intense radiation, risking hardware failure and blackouts as the field’s underlying, turbulent liquid iron core continues to shift.

Earth’s magnetic field acts as a vital shield against solar radiation and cosmic particles. This protective force is generated by a massive, swirling ocean of molten iron located approximately 3,000 kilometers beneath the surface. Much like a bicycle dynamo, this moving conductor creates electrical currents that sustain our planet's electromagnetic field. However, this process is far from uniform or static.

Data from the European Space Agency’s Swarm satellite constellation, which has provided the longest continuous record of space-based magnetic measurements since its 2013 launch, reveals that the South Atlantic Anomaly is not a singular, stable feature. Instead, it is a dynamic, evolving region. Since 2014, the anomaly has expanded significantly, and since 2020, researchers have observed an even more rapid weakening of the field in an area southwest of Africa. Experts suggest this behavior is linked to 'reverse flux patches'—unexpected zones at the core-mantle boundary where magnetic field lines point back into the core rather than outward.

The field's complexity extends beyond the South Atlantic. While the field has strengthened over Siberia, it has simultaneously weakened over Canada. These fluctuations are not merely academic; they influence navigation systems and highlight the turbulent nature of the Earth's core. Because the magnetic field is not a simple dipole, constant monitoring via missions like Swarm is essential to map these shifts. As the northern magnetic pole drifts toward Siberia, scientists continue to analyze these patterns to better understand the deep-seated forces that dictate the safety of our orbital infrastructure and the long-term stability of our planetary shield.

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