Date of Award

January 2015

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Earth, Atmospheric, and Planetary Sciences

First Advisor

Andrew M Freed

Committee Member 1

Christopher Andronicos

Committee Member 2

Ken Ridgway

Committee Member 3

Antonio Bobet


Understanding the viscous strength (rheology) of the mantle is essential for understanding the dynamics and evolution of the Earth. Rheology affects many geologic processes such as mantle convection, the earthquake cycle, and plate tectonics. This study uses tectonic (postseismic) and non-tectonic (lake unloading) events that have induced differential stress changes within the crust and mantle, which in turn, create surface deformation. The viscoelastic relaxation is constrained using geodetic methods, such as GPS, InSAR, or measurements of shoreline rebound. We can use these observed surface displacements to constrain numerical models of the relaxation processes that can be used to infer a viscosity structure. These studies allow us to infer the mechanical nature of the lithosphere and asthenosphere using 3D finite element models. When we combine our inferred viscosity structure with calculations of conductive geothermal gradients and models of mantle melting, we can infer environmental conditions of the upper mantle like water content, mineralogy, and degree of melt.