Rheology of Earth's mantle: bridging the gap between mineral-scale experiments and large-scale dynamics (co-organized)
|Convener: Patrick Cordier | Co-Conveners: Shun-ichiro Karato , Fanny Garel|
The dynamical processes that allow the solid Earth's mantle to evacuate its internal heat via 1000-km large convection cells originate at the nm scale where crystal defects promote plastic flow.
The viscosity of deep Earth materials can be inferred from both large scale observables integrated over millions of years as well as from laboratory experiments performed at shorter, human time scales.
Deformation experiments under HP-HT conditions give access to stress, strain or lattice preferred orientations, while numerical modeling of crystal creep laws puts new constraints on the physics of rheology for mantle minerals subject to more realistic, smaller deformation rates than experimental ones. On the other hand, geodynamic models can test whether these empirical rheology laws can be up-scaled so as to predict realistic motions of tectonic plates and global mantle.
A major challenge is to reconcile the "viscosity"-based view of fluid-dynamics models to the thermodynamical parameters derived from crystal-scale studies.
In this session, we encourage experimentalists, computational mineral physicists, geodynamicists and tectonophysicists to present their latest results and engage in a cross-disciplinary discussion leading to new insights.