Something odd is happening to Earth’s magnetic field. Over the last 200 years, it’s been slowly weakening and shifting its magnetic north pole (where a compass points, not to be confused with the geographic north pole) from the Canadian Arctic toward Siberia. In recent decades, however, that slow shift south has quickened — reaching speeds upwards of 30 miles per year. Could we be on the brink of a geomagnetic reversal, in which the magnetic north and south poles swap places?
Earth’s magnetic field is generated by the convection of molten iron in the planet’s core, around 1,800 miles beneath our feet. This superheated liquid generates electric currents that in turn produce electromagnetic fields. While the processes that drive pole reversal are comparatively less understood, computer simulations of planetary dynamics show that the reversals arise spontaneously. This is supported by observation of the Sun’s magnetic field, which reverses approximately every ...
