HR: 1340h
AN: U43B-0833    [Abstracts]
TI: Effect of Varying Mantle Rheology on Plate Motion
AU: * Koglin, D E
EM: dkoglin@purdue.edu
AF: Purdue University, 550 Stadium Mall Dr, West Lafayette, IN 47907 United States
AU: King, S D
EM: sking@purdue.edu
AF: Purdue University, 550 Stadium Mall Dr, West Lafayette, IN 47907 United States
AB: Recent investigations of mantle convection with mobile plates have documented a mode of convection with periodic and/or aperiodic plate reversals (2D) or reorganizations (3D) . In previous work, we have shown that it is possible to tune plate formulations so that three different modeling methods reproduce the same global flow diagnostics. In 2D calculations, plate reversals are independent of the method of plate generation once the calculations are tuned to reproduce the same physical characteristics (e.g., Nusselt number, and plate velocity). The period of oscillation of the flow reversals from three different plate methods are remarkably similar. Currently, we explore the effect of varying rheology on plate motion with imposed plates. Rheologies explored included dislocation and diffusion creep adding temperature temperature dependence, while systematically varying weak zone size and, where applicable, activation energy and activation volume, based upon experimental constraints found for olivine (e.g., Karato & Wu 1993). We find that while the surface velocity is dependent on weak zone size and mantle viscosity, the temperature field is primarily dependent on the viscosity of the mantle and the thickness of the overlying plate. Karato, Shun-ichiro, and Wu, Patrick, Rheology of the Upper Mantle: A Synthesis, Science, 260, 771-778, 1993
DE: 0545 Modeling (4255)
DE: 0560 Numerical solutions (4255)
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 8130 Heat generation and transport
SC: Union [U]
MN: Fall Meeting 2005