HR: 0800h
AN: T31A-1260    [Abstracts]
TI: A global coupled model of the lithosphere and mantle dynamics
AU: * Iaffaldano, G
EM: giampiero@geophysik.uni-muenchen.de
AF: Section of Geophysics at Ludwig-Maximilians University, Theresienstrasse 41, Munich, 80333 Germany
AU: Bunge, H
EM: bunge@lmu.de
AF: Section of Geophysics at Ludwig-Maximilians University, Theresienstrasse 41, Munich, 80333 Germany
AB: Understanding the dynamics of global lithospheric motion is one of the most important problems in geodynamics today. Mantle convection is commonly accepted as the driving force for plate motion but, while the kinematics of plate movement is well known from space geodetic and paleomagnetic observations, we lack a rigorous description of the coupled mantle convection-plate motion system. Here we present first results from a coupled mantle convection-global lithosphere motion model following a similar effort by Lithgow-Bertelloni and Guynn. Our plate motion code is SHELLS, a thinsheet FEM code developed by Bird which computes global plate motion and explicitly accounts for faults. The global mantle convection code is TERRA, a high-resolution 3-D FEM code developed and parallelized by Bunge and Baumgardner. We perform simple modeling experiments in which the shear tractions applied to the bottom of the lithosphere arise directly from the mantle circulation model. Our mantle circulation model includes a history of subduction and accounts, among others, for variations in mantle viscosity and strong bottom heating from the core. We find that our results are sensitive to the amount of core heating, an inference that has received renewed attention lately, and that models with stronger core heating overall are in better agreement with observations of intraplate stresses derived from the World Stress Map.
DE: 8110 Continental tectonics--general (0905)
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 8122 Dynamics, gravity and tectonics
DE: 8164 Stresses--crust and lithosphere
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting