Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 37 for “"seismic anisotropy"”.
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Seismic anisotropy in siliciclastic reservoir rocks
… of geophysical field measurements of seismic anisotropy is presently limited by our knowledge of the controls of the elastic anisotropy of sedimentary rocks in the subsurface. Traditionally, laboratory ultrasonic velocity measurements have been used to provide important information on …
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Seismic anisotropy and mantle flow beneath Africa and Arabia
… since 150 Ma, most likely causes the observed anisotropy across the Red Sea."--Abstract, page iv.</p>
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LATERALLY HETEROGENEOUS SEISMIC ANISOTROPY INVESTIGATED BY SHEAR WAVE SPLITTING ANALYSES
<p>"Numerous geophysical studies suggest that seismic anisotropy is a nearly ubiquitous property of the Earth’s crust and upper mantle. In this study, we utilize the shear wave splitting technique to investigate the piercing-point-dependent azimuthal anisotropy beneath the northeastern edge of the …
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Inversion of azimuthal velocity and amplitude variations for seismic anisotropy
… A pattern of vertical fractures causes the seismic wavefield to exhibit azimuthal anisotropy. The best way known to detect fractures, at large scales, is by recognizing the effect of them on seismic data in attempt of inversing it. The Altamont-Bluebell play is within the Uinta Basin in …
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Seismic anisotropy and microseismicity: from crustal formation to subduction termination
… in this cycle through the analysis of microseismicity and seismic anisotropy, seeking to learn more about the stresses in these environments and how they are manifest in the structure of the subsurface. In Iceland, new oceanic crust is accreted episodically within the volcanic rift zones …
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Seismic anisotropy in the Vaughan Lewis Glacier, Juneau Icefield, Alaska, 1969
Thesis (M.S.)--Michigan State University. Dept. of Geology, 1972
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Seismic anisotropy in tight gas sandstones, Rulison field, Piceance Basin, Colorado
Includes bibliographical references (pages 117-122).
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Towards using seismic anisotropy to interpret ductile deformation in mafic lower crust
… An understanding of the relationship between seismic properties, finite strain and fabric orientation thus provides a useful tool in the remote sensing and interpretation of deformation in the lower crust. This thesis outlines a work-flow model by which the seismic properties of a single and …
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Seismic anisotropy and mantle dynamics beneath the central and western United States
… recent availability of high-quality broadband seismic data from the USArray and other seismic stations in the central and western United States (CWUS) provide a distinct opportunity to test different anisotropy-forming mechanisms. For the first part of the study, a total of 4138 pairs of …
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3D trench-parallel flow in the subduction region and correlation with seismic anisotropy direction
The motivation of this study is to understand the seismic anisotropy observations from various subduction regions of the world. In subduction zone backarcs both trench-parallel and trench-normal seismic anisotropy, or fast wave polarization direction of shear wave, are observed. In the mantle the …
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Experimental deformation of forsterite, wadsleyite and ringwoodite: Implications for seismic anisotropy of the Earth’s mantle
… ringwoodite CPO for them being used to interpret seismic anisotropy. Finally, we suggest that strain-induced CPO might be responsible for the seismic anisotropy observed in the lowermost upper mantle and in the upper part of the transition zone. The low seismic anisotropy of the lowermost upper …
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The origins of olivine fabric transitions and their effects on seismic anisotropy in the upper mantle
… way is thought to be the principal cause behind seismic anisotropy in the upper mantle, which can consequently be used to chart convective flow of the mantle. Strong changes in seismic anisotropy occur in the top 300 km of the upper mantle where olivine is the principal mineral. In this study a …
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Estimating Seismic Anisotropy: Fluid Substitution Theory, 3D-Printed Inclusion Models, and Multi-Component 3D VSP in the Bakken Shale
Understanding seismic anisotropy is one of the most important issues in seismic exploration. In this dissertation, I tried to understand how fluids and lithology influence the elastic properties and seismic anisotropy of rocks, theoretically, experimentally, and in the field. I derived anisotropic …
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An exploration of the effect of anisotropy on seismic tomography in different geological settings
Seismic tomography is used in wide ranges to understand the inner structure of Earth based on the dependence of seismic velocity to temperature and other factors such as composition, volatile content, and seismic anisotropy. Despite it is well known that the mantle is seismically anisotropic, the …
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A new method to test shear wave splitting: improving statistical assessment of splitting parameters
… to be a very useful technique to probe for seismic anisotropy in the earth’s interior, and measurements of seismic anisotropy are perhaps the best way to constrain the strain history of the lithosphere and asthenosphere. However, existent methods of shear wave splitting analysis do not …
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Geochemical and rheological constraints on the dynamics of the oceanic upper mantle
… flow is by dislocation creep, resulting in seismic anisotropy due to mineral alignment. I use a shear zone in the Josephine Peridotite to quantify the relationship between mineral orientation and shear strain, providing an improved framework for the interpretation of seismic anisotropy. The …
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Geochemical and rheological constraints on the dynamics of the oceanic upper mantle
… flow is by dislocation creep, resulting in seismic anisotropy due to mineral alignment. I use a shear zone in the Josephine Peridotite to quantify the relationship between mineral orientation and shear strain, providing an improved framework for the interpretation of seismic anisotropy. The …
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A Geodynamic Investigation of Continental Rifting and Mantle Rheology: Madagascar and East African Rift case studies
… Preferred Orientation (LPO), known as seismic anisotropy. The predicted LPO isthen used to calculate synthetic seismic anisotropy, which were compared with observationsacross the island. Through a series of comparisons, we found that asthenospheric flow result-ing from undulations in …
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Elastic and viscous anisotropy in Earth's mantle : observations and implications
In this thesis I address the topic of anisotropy - the directional dependence of physical properties of rocks - from two complementary angles: I use seismic anisotropy to detect deformation in the mantle, and I demonstrate the importance of accounting for rheological anisotropy in mantle flow …
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Seismic investigations of the northern Transantarctic Mountains
… recent Transantarctic Mountains Northern Network seismic deployment, this dissertation integrates Rayleigh wave surface wave tomography, downward continuation and wavefield decomposition, and seismic anisotropy studies to better characterize the structure beneath the northern TAMs and to assess …
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