GEO 1111 Lecture Notes - Lecture 9: Mantle Convection, Post-Glacial Rebound, Rayleigh Number

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: Robert Jack Cornett

Document Summary

Two ways: conduction, heat energy transmitted through solid by molecular vibrations, a molecule phenomenon, slow process, convection, heat energy transmitted by density-driven fluid motion set up by the temperature gradient, fast process. We observed that the mantle transmits s-waves (i. e. , it is a solid) We have previously shown that the mantle is actively convecting (i. e. , the mantle is also a fluid viscoelastic) Uplift from when the glaciers were there (we would have kilometres of glaciers on top of us back millions of years) Postglacial rebound proves the mantle flows like a fluid; from the rate of rebound, the viscosity (resistance to flow) of the mantle can be calculated land has rebounded and the sea level has receded. Yes, because the mantle must be thermally convecting since it has a very high rayleigh number. Rayleigh number (ra), indicates whether or not convection will occur in a fluid that is being heated from below.