A fundamental assumption of paleomagnetism is that, over geological timescales, the Earth’s magnetic field approximates a geocentric axial dipole – a purely dipolar field (like a bar magnet’s) that is centred on the Earth’s rotation axis. But we know that over human timescales, this is not true: the geomagnetic pole is found at high latitudes, but some distance from the geographic pole, and is known to wander about from year to year, decade to decade, and century to century. How to reconcile the GAD hypothesis…Continue Reading “Paleomagnetism Lab: Testing the GAD hypothesis”