Physical Sciences and Mathematics Commons^™

Advances In Seismic First-Arrival Tomography, David Paul Gaines

Doctoral Dissertations

Seismic first-arrival tomography is a technique currently experiencing a renaissance in popularity due to the simplicity of implementation and promising results for delineating a variety of subsurface targets. The purpose of this study is to investigate seismic first-arrival tomography in a variety of settings and applications, and thus to provide a solid framework for future work. The study largely consists of two separate themes, hydrogeophysics and low-velocity anomaly detection. Hydrogeophysics is an emerging field whereby measured geophysical properties are used as proxies for physical properties of the subsurface. This study represents one of the first high-resolution hydrogeophysical investigations in the …

Strategies For Waveform Tomography Of Long-Offset, 2-D Exploration Seismic Data, Andrew J. Brenders

Electronic Thesis and Dissertation Repository

Waveform Tomography, combines starting models from traveltime tomography with tomographic waveform inversion. This approach to inversion recovers a “best fit” velocity model by iteratively minimizing the misfit between the observed, frequency-domain waveform data and modelled, synthetic waveforms. The method is both computationally efficient and an improvement over ray-based tomographic methods. Synthetic benchmark studies and experiments with long-offset, 2-D, exploration seismic field data, demonstrate that Waveform Tomography can yield accurate, high resolution velocity models, vital in seismic exploration for hydrocarbons.

I first present an application of Waveform Tomography to long-offset, 2-D, synthetic marine seismic data using the 2004 BP velocity benchmark. …

Gpu Based Parallel Smoothing Of Seismic Tomography Models, Ivan Gris

Open Access Theses & Dissertations

Three-dimensional models of the velocity structure of the Earth's crust are an important and relevant factor for several types of analyses across disciplines. Crustal velocity models are also commonly used to analyze and search for different materials of interest or to determine and differentiate many aspects of life on Earth during different eras.

Seismic tomography techniques, both in two and three dimensions, perform image reconstruction of the crust of the Earth. Seismic tomography algorithms can calculate crustal velocity structure through inversion of traveltimes of seismic waves produced by natural events, such as earthquakes, or controlled source experiments, such as explosions. …