What Caused Recent Acceleration of the North Magnetic Pole Drift?

Abstract

The north magnetic pole (NMP) is the point at the Earth's surface where the geomagnetic field is directed vertically downward. It drifts in time as a result of core convection, which sustains the Earth's main magnetic field through the geodynamo process. During the 1990s the NMP drift speed suddenly increased from 15 kilometers per year at the start of the decade to 55 kilometers per year by the decade's end. This acceleration was all the more surprising given that the NMP drift speed had remained less than 15 kilometers per year over the previous 150 years of observation.