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Full-Text Articles in Physical Sciences and Mathematics

A Modeling Study Of O2 And Oh Airglow Perturbations Induced By Atmospheric Gravity Waves, Alan Z. Liu, Gary R. Swenson Oct 2013

A Modeling Study Of O2 And Oh Airglow Perturbations Induced By Atmospheric Gravity Waves, Alan Z. Liu, Gary R. Swenson

Alan Z Liu

A one-dimensional model is used to investigate the relations between gravity waves and O2 and OH airglows perturbations. The amplitude and phase of the airglow perturbations induced by gravity waves (with period > 20 min) are calculated for different vertical wavelength (10–50 km) and damping rate. The model shows that for vertically propagating gravity waves, the amplitude of airglow perturbations observed from ground is larger for longer vertical wavelength, because of the smaller cancellation effect within each layer. The ratio of the amplitudes between O2 and OH is smaller for larger wave damping. For upward propagating (downward phase progression) waves, the …


Integrated Geophysical Investigation Of The St. James Fault Complex: A Case Study, Robert W. Jacob, Jeremy B. Byler, Mary Beth Gray Sep 2013

Integrated Geophysical Investigation Of The St. James Fault Complex: A Case Study, Robert W. Jacob, Jeremy B. Byler, Mary Beth Gray

Faculty Journal Articles

We noninvasively detected the characteristics and location of a regional fault in an area of poor bedrock exposure complicated by karst weathering features in the subsurface. Because this regional fault is associated with sinkhole formation, its location is important for hazard avoidance. The bedrock lithologies on either side of the fault trace are similar; hence, we chose an approach that capitalized on the complementary strengths of very low frequency (VLF) electromagnetic, resistivity, and gravity methods. VLF proved most useful as a first-order reconnaissance tool, allowing us to define a narrow target area for further geophysical exploration. Fault-related epikarst was delineated …


Weyl Gravity As A Gauge Theory, Juan Teancum Trujillo May 2013

Weyl Gravity As A Gauge Theory, Juan Teancum Trujillo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A gauge theory is a theory in which the governing functional, known as the action, remains invariant under a continuous group of local transformations that form its symmetry. Each of the known fundamental interactions in the universe, such as electricity and magnetism, can be explained as arising from a particular gauge theory. Gravitation is no exception. Just as calculus can be used to find the value of a variable that maximizes or minimizes a function, calculus of variations can be used to find the equations, known as the field equations, that extremize the action, and these are the main equations …


On Different Techniques For The Calculation Of Bouguer Gravity Anomalies For Joint Inversion And Model Fusion Of Geophysical Data In The Rio Grande Rift, Azucena Zamora Jan 2013

On Different Techniques For The Calculation Of Bouguer Gravity Anomalies For Joint Inversion And Model Fusion Of Geophysical Data In The Rio Grande Rift, Azucena Zamora

Open Access Theses & Dissertations

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 …


Software Development For A 3d Gravity Inversion And Application To Study Of The Border Ranges Fault System, South-Central Alaska, Rolando Cardenas Jan 2013

Software Development For A 3d Gravity Inversion And Application To Study Of The Border Ranges Fault System, South-Central Alaska, Rolando Cardenas

Open Access Theses & Dissertations

The Border Ranges Fault System (BRFS) bounds the Cook Inlet and Susitna Basins, and is an important petroleum province within south-central Alaska. A primary goal of our research is to test several plausible models of structure along the BRFS using a novel three-dimensional inversion technique utilizing gravity data, constrained with other geophysical, borehole and surface geological information. This research involves the development of 3D inversion modeling software using C++ Builder from Embarcadero's XE2 Suite. The novel inversion approach directly models known geology with a priori uncertainties assigned to the geologic model to allow researchers to compare alternative interpretations. This technique …