Ph.D - Geology/Geophysics/Numerical Modelling
University Of California, Davis
Estimated Graduation: June 2016Thesis: The effects of phase transitions, compositional layering and the overriding plate on two-dimensional numerical models of subduction zonesAdvisor: Magali I. BillenBuild and implement 2-D geodynamic, time-dependent computer simulations of subduction zones with non-Newtonian viscoplastic rheology and investigate how internal forces affect surface plate speeds and behavior, such as trench migration and slab stagnation:• Test a self-consistent mineralogical model with eight phase transitions and compositional layers of basalt, eclogite, harzburgite and pyrolite.1. Collect interdisciplinary data from mineral physics, seismology, petrology and geophysics.2. Combine into model that can be designed and written into convection code, CitcomS.• Analyze the impact of different incompressible approximations of the momentum and energy governing equations, such as the presence of latent heat, adiabatic heating and shear heating.1. Increased awareness of assumptions and limitations of models, past and present.• Compare the effect of kinematic boundary conditions, where plate speeds are directly controlled, to dynamic conditions where the plates can react to internal forces by changing slab velocities, trench migration, formation of accretionary prisms and foreland basins and slab break-off. 1. Designed usable models when reaching edge of convection code usability.2. Devised solutions to convergence problems and supervised slow-to-converge models with good data.3. Combine interdisciplinary data from structural geology and geophysics.• Determine how these different model configurations affect slab internal stress through time and compared with observations of deep earthquakes. Results: Two peer-reviewed papers, one accepted and one in preparation.
