HR: 1340h
AN: T43B-1321    [Abstracts]
TI: Numerical models of the Earth's thermal history
AU: * Butler, S L
EM: sam.butler@usask.ca
AF: Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2 Canada
AU: Peltier, W R
EM: peltier@atmosp.physics.utoronto.ca
AF: Department of Physics, University of Toronto, 60 St George St, Toronto, ON M5S 1A7 Canada
AB: A number of different scenarios have emerged for the thermal evolution of the Earth which is controlled by the slow convective motion in the mantle in order that it meet the constraint imposed by the modern-day surface heat flow. These include models with high internal heating rates in the mantle, models with significant degrees of internal heating in the core, models with large and/or time-varying degrees of layering at 660-km depth and models with weak feedback between surface heat flow and mantle Rayleigh number. Most investigations of the Earth's thermal evolution have been carried out using parameterized convection studies in which the governing equations are significantly simplified. In this contribution, we compare the results of more complex numerical models with those of parameterized models for the various thermal history scenarios described above. Although these types of models are in general agreement in a time-averaged sense, only the former can assess short-timescale and lateral variability and these allow for new constraints to be brought to bear.
DE: 8121 Dynamics, convection currents and mantle plumes
DE: 8124 Earth's interior--composition and state (old 8105)
DE: 8125 Evolution of the Earth
DE: 8130 Heat generation and transport
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting