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Pole flips tied to plate tectonics

Lopsided arrangement of continents could lead to reversals in Earth's magnetic field

Continents moving around over millions of years in the slow-motion geologic jigsaw puzzle known as plate tectonics could trigger the occasional swapping of the north and south magnetic poles.

Assumed to be caused by random fluctuations in the circulation of the molten iron core, the flips may actually be tied to what’s going on at Earth’s surface. At times in the geologic past when landmasses have bunched together on one side of the equator, the Earth’s magnetic field has begun flipping soon thereafter, suggests a study to appear in Geophysical Research Letters.

“What we see clearly is that the surface positions of the continents are linked with the frequency of the reversals,” says group member François Pétrélis, a geophysicist at the French research agency CNRS in Paris.

Other scientists aren’t so sure, cautioning that more work needs to be done to confirm any such link.

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