The effects of near-receiver structure on teleseismic and regional waveforms

The two distinct parts to this dissertation deal with isolating the effect of structure immediately beneath seismic stations on seismic waveforms. The first part deals with the inference of velocity discontinuities beneath a single broadband 3-component seismic station using receiver functions, in which the P-to-S converted phases generated beneath a seismic station are isolated by deconvolution of the horizontal component seismograms by the vertical.; We improve the deconvolution itself by the development of a time domain inversion for the receiver function. We extend the technique's application to an area of complex structure, using data collected at Pinon Flat Observatory, California, where we improve understanding of the region's structure and tectonic framework. We are able to make inferences about complex Moho topography and corroborate them using observations of P-PmP differential times, and P-wave polarizations. We also analyze the uncertainties in receiver function waveforms using both synthetic and real data, demonstrating that regularized deconvolution of noisy seismograms significantly biases receiver function amplitudes.; The second part of the dissertation deals with the effect of near receiver velocity structure on seismic wave amplitudes. We use the near-receiver-scattered component of teleseismic coda to calibrate site amplifications for the southern California seismic network. This required the development of a technique to separate the near-receiver-scattered component of teleseismic coda from the near-source-scattered component. We also developed and applied appropriate statistical analysis tools to permit accurate estimation of the site amplifications from the doubly censored non-Gaussian data. Specifically, we use maximum likelihood estimation to incorporate censored data, and the robust statistical technique of iteratively reweighting the inversion based on the misfit to reduce biasing of parameter estimates by outliers.; The main purpose of estimating site amplifications has been to enable isolation of propagation effects on Lg amplitudes, which is important to understand for accurate monitoring of nuclear testing. We conclude with the application of the site amplifications to Lg of regional events, demonstrating that they are successful in isolating propagation from site effects on Lg amplitudes.