On A Particular Solution of the Non‐Linear Liouville Equations

The rotational behaviour of a stratified viscoelastic planet is analysed by means of a quasi-analytical method. Our approach is particularly appropriate to study the long-term polar wander induced by internal loads, and in particular to study the effects due to time-dependent mantle convection. We focus on a simple explicit solution of the Liouville non-linear equations, in order to establish the relationships between internal rheological constitution of the planet and polar motion. Both the rate and the direction of polar wander are found to be extremely sensitive to the mantle stratification and in particular to the nature of the 670km depth seismic discontinuity.