## Polar motions excited by a convecting viscous mantle

**J. Moser** ** , **
**David A. Yuen** ** & **
**Ctirad Matyska**
### Summary

The role played by time-dependent mantle convection on exciting long-term
polar motions is examined by means of a viscous model. For sufficiently low
effective viscosity, polar wander speeds of O(1 deg/Myr) would require
contributions from the off-diagonal elements of the inertia tensor, with
magnitudes around 10^{5} times smaller than
those found in viscoelastic
models used for postglacial rebound. Contributions from the large-scale
mantle flow to the angular momentum vector can be comparable to those
due to changes in moment inertia tensor for non-linear rheology or for
young plantes. The relative roles of the two contributions depend on the
non-linear rheology of the mantle and its convective vigor.

Geophys. Res. Lett., **19** (1992), 2251-2254.