HR: 0800h
AN: U21A-0004    [Abstracts]
TI: Influence of Rheology on the Lengthscale of Mantle Convection
AU: * Höink, T
EM: tobias.hoeink@rice.edu
AF: Department of Earth Science, Rice University, 6100 Main St, Houston, TX 77005, United States
AU: Lenardic, A
EM: adrian@rice.edu
AF: Department of Earth Science, Rice University, 6100 Main St, Houston, TX 77005, United States
AB: In the debate of whole vs. layered mantle convection much attention has been paid to the vertical extent of convection planforms. Closely connected and potentially equally important in this discussion is the horizontal lengthscale of mantle convection. Studies that have addressed the horizontal lengthscale of mantle convection have found that prescribing a shallow low viscosity channel in convection models can be crucial for promoting long wavelength flow. However, work involving self-consistent mantle models, in which viscosity is a function of temperature, depth, and yield stress, have not readily observed long horizontal wavelengths. In this work, rather than prescribing a low viscosity channel, we generate one in numerical mantle convection models by using a temperature and pressure dependent rheology. We explore which rheologic ingredients are necessary for a shallow low viscosity channel to develop, and which degree of "channeliness" facilitates long wavelength convection and plate-like motion. Our numerical experiments may help constrain which mode of mantle convection is dominant in Earth's mantle.
DE: 5724 Interiors (8147)
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
DE: 8121 Dynamics: convection currents, and mantle plumes
DE: 8162 Rheology: mantle (8033)
SC: Union [U]
MN: 2007 Fall Meeting