My primary topic of research includes determining complex seismic velocity structures within the solid earth, primarily the crust and upper mantle. This is accomplished through seismic waveform modeling in 1, 2 and 3-D and the utilization of a number of programs which compute synthetic seismograms. Of particular interest are highly complex and unusual seismic signals resulting from exotic sources and/or complex seismic wave propagation. Computation of synthetics seismograms, especially in 3D, takes place in massively parallel computers housed within the department and at super computing centers around the world.