Geomagnetic Reversal
A major planetary event during which Earth's magnetic field undergoes a complete polarity flip, swapping magnetic North and South poles.
Governing formula
Reversal Interval ~ 200,000 to 300,000 years
SI unit
Geologic Time Interval
In depth
Driven by chaotic turbulent flow fluctuations in outer core geodynamo fluid currents. Reversals occur over a few thousand years, leaving permanent magnetization signatures locked into cooling lava basalt rocks (thermoremanent paleomagnetism).
Examples in the real world
Symmetrical magnetic anomaly 'stripes' recorded on the ocean floor on either side of the Mid-Atlantic Ridge.