Date of Award

2013-01-01

Degree Name

Master of Science

Department

Computational Science

Advisor(s)

Aaron A. Velasco

Abstract

Density variations in the Earth result from different material properties, which reflect the tectonic processes attributed to a region. Density variations can be identified through measurable material properties, such as seismic velocities, gravity field, magnetic field, etc. Gravity anomaly inversions are particularly sensitive to density variations but suffer from significant non-uniqueness. However, using inverse models with gravity Bouguer anomalies and other geophysical data, we can determine three dimensional structural and geological properties of the given area. We explore different techniques for the calculation of Bouguer gravity anomalies for their use in joint inversion of multiple geophysical data sets and a model fusion scheme to integrate complementary geophysical models. Various 2- and 3- dimensional gravity profile forward modeling programs have been developed as variations of existing algorithms in the last decades. The purpose of this study is to determine the most effective gravity forward modeling method that can be used to combine the information provided by complementary datasets, such as gravity and seismic information, to improve the accuracy and resolution of Earth models obtained for the underlying structure of the Rio Grande Rift. In an effort to determine the most appropriate method to use in a joint inversion algorithm and a model fusion

approach currently in development, we test each approach by using a model of the Rio Grande Rift obtained from seismic surface wave dispersion and receiver functions. We find that there are different uncertainties associated with each methodology that affect the accuracy achieved by including gravity profile forward modeling. Moreover, there exists an important amount of assumptions about the regions under study that must be taken into account in order to obtain an accurate model of the gravitational acceleration caused by changes in the density of the material in the substructure of the Earth.

Language

en

Provenance

Received from ProQuest

File Size

84 pages

File Format

application/pdf

Rights Holder

Azucena Zamora

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