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 19 of 19 for “"Subsurface structures"”.
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Time Reversed Acoustics and applications to earthquake location and salt dome flank imaging
… (TRA) to locate seismic sources and image subsurface structures. The back-propagation process of the TRA experiment can be divided into the acausal and causal time domain. Studying the acausal process of TRA enables us to locate the source, such as an earthquake, inside a medium. The causal …
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Efficient seismic imaging with the double plane wave data
… critical in providing the image of the Earth’s subsurface, and it plays an important role in hydrocarbon explorations. Obtaining high resolution images with accurate reflectivities and accurate positions of subsurface structures is the goal for exploration geophysicists. Reverse time migration …
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Seismic Modeling and Imaging for Detection of Clandestine Tunnels
… absorption, and heterogeneity of complex subsurface structures. Instead, by assigning proper parameters into numerical modeling and projecting, the modeled results derived from these forward numerical model examples may allow us to investigate the seismic detection capability under optimal …
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Detailed Structural and Stratigraphic Analysis of the Salt-Sediment Interactions on Top of the Wheeler Dome Salt Tongue, Mississippi Canyon Area, Gulf of Mexico
… In this area, there are many different salt structures present including salt canopies, diapirs, and salt pillows. The Callovian aged Louann Salt covers this area and is the cause of many of the salt structures and structures of the overlying formations seen in Gulf of Mexico today. Salt is …
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Feasibility of Spinal Neuronavigation and Evaluation of Registration and Application Error Modalities Using Optical Topographic Imaging
… navigation began with the localization of subsurface structures in cranial neurosurgery using frame-based stereotaxy. Advances in imaging and computing power have led to the development of modern frameless three-dimensional (3D) computer-assisted navigation (CAN), employed across multiple …
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Integrity Assessment Of Earthen Dams And Levees Using Cross-Plot Analysis Of Seismic Refraction And Electrical Resistivity Tomograms
… non-invasive, and spatial coverage of the subsurface in terms of geophysical properties. On the other hand, geophysical methods can generate multiple geophysical anomalies. An anomaly on a seismic refraction or an electrical resistivity tomogram is an area that has different values compared …
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Application of Ground Penetrating Radar to Study the Internal Architecture of Coastal Dunes, North Padre Island, Texas
… natural dune contains well-developed internal structures and is homogenous. The data for the maintained dune contains discontinuous reflectors in the pre- processed data, a water table, dune core, foreslope accretion, and biotopographic accumulation. The discontinuous reflectors suggest that …
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Ambient seismic noise tomography of the southern United States and seismic inversion with dictionary learning using unsupervised machine learning.
… are well-established methods to understand deep subsurface structures. These techniques are particularly effective in delineating complex crustal architectures, which often deviate from simplified textbook models. High-resolution seismic tomography enables the interpretation of such intricate …
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Three-dimensional magnetotelluric modelling of the Taupo Volcanic Zone, New Zealand
… to be achievable a better understanding of the structures that control fluid flow is required. The conductive hydrothermal alteration minerals and fluids associated with high-temperature geothermal systems in an otherwise resistive volcanic environment provide a distinct contrast in electrical …
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Variable grid finite-difference modeling including surface topography
… method for highly complex surface topography and subsurface structures. Realistic modeling of seismic wave propagation in the near surface region is complicated by many factors, such as strong heterogeneity, topographic relief and large attenuation. In order to account for these complications, we …
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Design for a mind with many bodies : cybernetic micro-interventions in the cryosphere
… research shows direct correlations between the subsurface structures of a glacier and the activity observed on its surface, as well as how it decays and moves through time. [2] Similarly, the study of ice suggests that, depending on its composition, environmental flux, and method of freezing, …
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Crustal structures and the Eastern extent of the Lower Paleozoic Shelf Strata within the Central Appalachians: a seismic reflection interpretation
… delineated Grenvillian, Paleozoic and Mesozoic structures within the Appalachian foreland, Blue Ridge, and Piedmont of the central Appalachians. The eastern portion of PR3 can be correlated along strike with the western portion of line 1-64, reprocessed earlier at Virginia Tech. The 1-64 seismic …
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Anomalous transport through porous and fractured media
… Traditionally, seismic interpretation of subsurface structures is performed without any account of flow behavior. With the proposed methodology, we reduce the uncertainty by integrating dynamic flow measurements into the seismic interpretation, and improve the predictability of reservoir …
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Tectonic and climatic controls on orogenic processes : the Northwest Himalaya, India
… isostatic compensation process. Alternatively, subsurface structures can have significant influence in the evolution of this actively growing orogen. Along the southern Himalayan front new 40Ar/39Ar white mica and apatite fission track (AFT) thermochronologic data provide the opportunity to …
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Advanced analysis of complex seismic waveforms to characterize the subsurface Earth structure
… analysis of microtremor to characterize the subsurface structure in urban areas, and (3) Surface wave dispersion inversion for shear wave velocity structure. Although these three projects apply different techniques and investigate different parts of the Earth, their aims are the same, which …
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Hydrological processes in volcanic ash soils : measuring, modelling and understanding runoff generation in an undisturbed catchment
… the fast response signal, however, while lateral subsurface flow was observed at several soil moisture profiles, the location and type of structures causing fast lateral flow on the hillslope scale is still not clear and needs to be investigated in more detail. Surface runoff has not been observed …
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Subsurface Planetary Investigation Techniques and Their Role for Assessing Subsurface Planetary Composition
<p>Subsurface planetary investigation techniques are of high interest and importance for the scientific community. Not only they can enhance our knowledge of the history of planetary formation but also can lead to information about its future. Whether the investigation is being conducted remotely …
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Deep submarine volcanoes in two geodynamic settings (Canary Basin and Gulf of Cadiz): morphology and shallow structure
… areas, based on their morphological features and subsurface structures in order to determine their relationships with recent geological, sedimentary, and oceanographic processes and establish the dominant mechanisms controlling their morphological evolution. These seafloor structures are …
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CENOZOIC EXTENSION OF THE LAKE TANGANYIKA RIFT, EAST AFRICA: STRUCTURES, TECTONOSTRATIGRAPHY AND PALEOENVIRONMENTAL RECONSTRUCTION
… Constraining the geometry of geological structures in extensional basins such as those within the EARS is important for studies of sedimentation, limnology, and hazards. Although previous studies have mapped geological structures of the Lake Tanganyika Rift in East Africa, many aspects of …