Polar wandering in mantle convection models
- Abstract
We calculate polar motion in models of 3-D spherical mantle convection at Rayleigh numbers up to 10exp8 which include internal heating, radial viscosity variations, and an endothermic phase change. Isoviscous models yield rapid polar motion of order 3 degree/Myr, but a factor of 30 increase in viscosity with depth reduces the rate of polar motion to about 0.5 degree/Myr due to stabilization of the large-scale pattern of convection. Avalanching due to an endothermic phase change causes pulsating inertial interchange polar excursions of order $80-110^o$ and of duration 20-70 Myr. A layered viscosity model with an endothermic phase change yields only one inertial interchange event in 600 million years. These models show that the slow observed rate of post-Paleozoic true polar wander is not incompatible with higher rates inferred for earlier times.
- BibTeX
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@article{id73, author = {Richards, M.A. and Bunge, H.-P. and Ricard, Y. and Baumgardner, J.R.}, journal = {Geophys. Res. Lett.}, language = {en}, pages = {1777 - 1780}, title = {Polar wandering in mantle convection models}, volume = {26}, year = {1999}, }
- EndNote
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%O Journal Article %A Richards, M.A. %A Bunge, H.-P. %A Ricard, Y. %A Baumgardner, J.R. %J Geophys. Res. Lett. %G en %P 1777 - 1780 %T Polar wandering in mantle convection models %V 26 %D 1999