VirtualEarth Virtual Earth

Modeling Viscoelastic Stress Relaxation Using CitcomVE
3 - Rheology and Constitutive Laws

The mantle rheology describes how rocks deform or flow under mantle T and P conditions. Two common ways to study the rheology are 1) to examine how rocks deform in the laboratory under conditions as realistic as one can achieve and 2) to model Earth's response to certain forcings (e.g., post- glacial rebound).

It is generally agreed that mantle rocks are much weaker and easier to deform under higher T. However, mantle viscosity increases with P. In some part of the mantle, deformation is accommodated via diffusion creep, while dislocation creep is the dominant deformation mechanism in other part of the mantle. For dislocation creep deformation, mantle viscosity also depends on stress and is controlled by what is often called power-law rheology.

In most studies of mantle convection, we employ a simplified rheology, say, only temperature-dependent rheology or even uniform viscosity, as in the project.


© 2003 - University of Colorado
Acknowledgement: Partially supported by NSF. Joshua Yambert helped build the user interface. Louis Moresi provided the 2-D convection code.