Scaling rates of true polar wander in convecting planets and moons

摘要

Highlights?We develop a framework for analyzing true polar wander (TPW) from a perspective of fluid dynamics.?We identify a small set of nondimensional numbers which characterize the rates of true polar wander for a convecting planet.?We develop scalings for both the driving forces of TPW and the planetary response in terms of the nondimensional numbers.?We present numerical simulations supporting our scaling analyses.AbstractMass redistribution in the convecting mantle of a planet causes perturbations in its moment of inertia tensor. Conservation of angular momentum dictates that these perturbations change the direction of the rotation vector of the planet, a process known as true polar wander (TPW). Although the existence of TPW on Earth is firmly established, its rate and magnitude over geologic time scales remain controversial. Here we present scaling analyses and numerical simulations of TPW due to mantle conve