The PIs will use the fully parallel Sepran finite element code to generate high resolution 3D models of subduction zones that can be used to overcome the limitations of 2D models. The 3D approach will allow them to investigate the influence of along-strike variations in slab parameters such as slab-dip, age of incoming lithosphere, direction and speed of convergence, and lateral variations in properties of the overriding plate. This approach will also allow them to quantify the influence of along-strike wedge flow, which is likely to occur near slab edges or can be generated when pressure gradients in the overlying wedge are induced by lateral variations in the subduction zone geometry. This collaborative effort will constrain the model geometry by the best available local observations from seismology and plate kinematics. They will test the models using seismological observations of wedge velocity and anisotropy structure. The main scientific goals to be accomplished are: 1) the application of the 3D models to a selected number of present-day subduction zones with significant along-strike variations in slab input or observables; 2) an investigation of the influence of arc-parallel flow on mantle wedge conditions near the edges of subduction zones. The potential broader impacts of this project involve the training of three graduate students will be trained as a part of this effort, at Michigan, Brown and Boston University.
