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 13 of 13 for “"Subseafloor"”.
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Microbial communities, activities, and metabolisms in Earth’s subseafloor and analog oceanic environments
The crustal subseafloor biosphere is one of the largest and most underexplored habitats on Earth. Microorganisms inhabiting this environment contribute to chemical transformations, energy flow, and the long-term habitability of the oceanic crust, while also offering insight into the potential for …
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Fluid Flow Processes at Mid-Ocean Ridge Hydrothermal Systems
The subseafloor structure and temporal variability of mid-ocean ridge hydrothermal systems are examined from a largely theoretical standpoint. The nature of tidal signals is considered in detail and there is a discussion of the mechanisms by which the tidal modulations observed at seafloor …
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Seismic scattering of low-grazing-angle acoustic waves incident on the seafloor
… the seafloor in terms of seafloor structure and subseafloor geological properties. Specifically, this work has been directed towards the interpretation of matched-filtered, beamformed monostatic acoustic reverberation data acquired on the west flank of the Mid-Atlantic Ridge when the seafloor is …
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Seismic scattering of low-grazing-angle acoustic waves incident on the seafloor
… the seafloor in terms of seafloor structure and subseafloor geological properties. Specifically, this work has been directed towards the interpretation of matched-filtered, beam-formed monostatic acoustic reverberation data acquired on the west flank of the Mid-Atlantic Ridge when the seafloor is …
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Quantification of total microbial biomass and metabolic activity in subsurface sediments
… shown that the global geographic distribution of subseafloor sedimentary microbes varies between sites by 5 to 6 orders of magnitude and correlates with the sedimentation rate and distance from land. Based on these correlations, global subseafloor biomass was estimated to be 4.1 petagram-C and …
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Carbon and mineral transformations in seafloor serpentinization systems
… with carbon-bearing aqueous fluids in the subseafloor, dissolved inorganic carbon can precipitate as carbonate minerals or undergo reduction by H2(aq) to form reduced carbon species. In Chapters 2 and 3, I conduct laboratory experiments to assess the relative extents of carbonate formation …
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Carbon and mineral transformations in seafloor serpentinization systems
… with carbon-bearing aqueous fluids in the subseafloor, dissolved inorganic carbon can precipitate as carbonate minerals or undergo reduction by H2(aq) to form reduced carbon species. In Chapters 2 and 3, I conduct laboratory experiments to assess the relative extents of carbonate formation …
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Distribution of Dehalococcoidia in marine sediments and strategies for their enrichment
… no specific respiratory mode to be preferred by subseafloor Dehalococcoidia. Additionally, subseafloor Dehalococcoidia were not reliant on organohalide respiration under the conditions tested, in contrast to cultivated Dehalococcoidia species such as Dehalococcoides mccartyi. Interestingly, among …
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Productivity, metabolism and physiology of free-living chemoautotrophic Epsilonproteobacteria
… biomass residence time of the deep-sea vent subseafloor biosphere were estimated. Finally, the population structures of the most abundant genera Sulfurimonas and Thioreductor were shown to be strongly influenced by pO2 and temperature respectively, providing a mechanism for niche …
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Productivity, metabolism and physiology of free-living Chemoautotrophic Epsilonproteobacteria
… biomass residence time of the deep-sea vent subseafloor biosphere were estimated. Finally, the population structures of the most abundant genera Sulfurimonas and Thioreductor were shown to be strongly influenced by pO₂ and temperature respectively, providing a mechanism for niche …
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The Thermal and Fluid Environment of the Cascadia Subduction Zone, Southern Washington State
… data provides valuable insight into seafloor and subseafloor fluid and geological processes. Thus, understanding the uncertainties associated with heat flow instruments is essential to the interpretation of acquired data. While there have been studies of various instruments’ ability to accurately …
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Microbial nitrogen-cycling and cooperation in the terrestrial subsurface
… environments, and other environments (such as subseafloor crustal fluid, alpine thermal spring water, sulfur rich hydrothermal vent sediments and soils), sheds light on the divergent metabolic capacities between well-characterised Nitrospirota (characterised predominantly by aerobic nitrifiers) …
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Seismic constraints on shallow crustal processes at the East Pacific Rise
… ASC, or travels laterally from the ASC through subseafloor conduits. Off-axis sill emplacement also contributes to the thickening of layer 2A. According to this model, the shallow crustal architecture is in place within 1-2 km of the rise axis. We suggest that the process of dike subsidence is …