Teleseismic Transmission and Reflection Tomography

The aim of seismic tomography is to determine a model of Earth properties that best ex-plain observed seismic data. In practice, the limitations placed on our observations and computational capabilities force us to make a number of decisions about the scales and parameterizations of models, the nature of the data considered, and the approximations to wave propagation that connect the two. This thesis will consider three divergent approaches to seismic tomography spanning different representations of Earth structure at different scales, using different parts of the teleseismic wavefield, and solving the inverse problem with different approximations to the wave equation and different optimization methods. In choosing each of these approaches, we address two major decisions that influence the tomographic process: First, what relative value do we place on an less approximate treatment of wave physics versus the ability to incorporate as much information as possible in our inversion? Second, how can we use novel data to better constrain smooth seismic structure in regions that were previously unresolved