True polar wander in mantle convection models with multiple, mobile continents

The geologic record supports numerous instances during which continents apparently moved at speeds significantly faster than any of today's tectonic plates. While the time dependence of convective driving forces likely explains some such observations, rapid motions of large continents in particular are often attributed to true polar wander (TPW). In order to gauge the potential for connections between continents, mantle temperature anomalies, and polar motion, we present the first calculations of TPW derived from models that couple mantle convection with multiple, mobile continents. We find that the aggregation and dispersal of supercontinents can lead to two types of TPW, driven either by a well developed hot upwelling axis that creates a stable maximum moment of inertia, or by the homogenization of mantle thermal structure following continent dispersal that leads to destabilization of the principal axis and possible large magnitude polar wander. These supercontinent-modulated thermal heterogeneities drive model TPW events as large as 90° at rates of up to 2.5° Ma− 1. Such magnitudes and speeds are greater than those attained in similar models lacking continents, but comparable to those for episodes inferred from paleomagnetic data for some large continents in the past.