Refraction tomography methods applied to shallow seismological imaging
No Thumbnail Available
Authors
Meeting name
Sponsors
Date
Journal Title
Format
Thesis
Subject
Abstract
Seismic tomography is widely used to explore the earth's subsurface at a variety of different scales. An important seismological tool to image the relatively shallow part of the subsurface at high resolution is refraction tomography, which uses active sources and observations of the associated travel times rather than passive sources which are used for the deeper parts of the earth. Similar to local and teleseismic travel time tomography this approach attempts to match predicted travel times. I have tested a number of different types of refraction tomography algorithms to learn the benefits and disadvantages of each method. After determining the optimal approach, I have applied the techniques of inverse theory to produce tomographic data gathered from high resolution refraction seismic array in Triplett, Missouri, as well as doing synthetic tests of our study area in order to identify the best refraction tomography tool for use in addressing shallow geophysical imaging problems. The Triplett project examines a potential subsurface fault and its resulting surface expression to determine which tomography algorithms can identify the potential fault throw the best, and to what extent they can synthetically model other potential subsurface structures. The core program used in this study is a Python module package called pyGIMLi (Rücker et al 2017), and a software package based on pyGIMLi referred to as Refrapy (Guedes et al 2022). In this study, I have used refraction tomography to model travel time data collected in Triplett, Missouri, and I have used the final seismic velocity model as a basis for comparison for several simulation tests that help determine the resolution of the tomographic models. I attempt to determine the accuracy of the field data model with resolution tests, and I attempt to determine the resolution of a number of different hypothetical examples of fault throw and geometry. Finally, I list our studies conclusions and important future research directions that can be taken using the framework described in this thesis.
Table of Contents
DOI
PubMed ID
Degree
M.S.