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dc.contributor.advisorSager, Williamen_US
dc.creatorThomas, Ryan Douglasen_US
dc.date.accessioned2004-11-15T19:48:47Z
dc.date.available2004-11-15T19:48:47Z
dc.date.created2003-08en_US
dc.date.issued2004-11-15
dc.identifier.urihttp://hdl.handle.net/1969.1/1176
dc.description.abstractIn the northern Gulf of Mexico, seafloor hydrocarbon fluid and gas seepage is an ubiquitous process on the continental margin. Although seafloor seepage and seep-related features (mud volcanoes, carbonate formation) have been studied for many years, little is known about their mechanisms of formation and the relationship of sub-surface structure to current seep activity. In this study, we examined three seafloor seeps in the Garden Banks and Mississippi Canyon areas using exploration and reprocessed 3D multi-channel seismic (MCS) data augmented with side-scan sonar (Garden Banks site) to characterize hydrocarbon seep activity and develop an understanding of the processes that led to their formation. Side-scan sonar data provided high resolution coverage of the seafloor while the exploration seismic data were used to image near and deep sub-surface features. Additionally, the 3D amplitude extraction maps were useful in delineating amplitude anomalies often associated with seep related activity. The reprocessed 3D seismic data were used to map in greater detail near seafloor features and amplitude anomalies. Using remote sensing geophysical data, we were effectively able to map sub-surface features such as salt topography, seep-related faults and geophysical indicators of hydrocarbons and correlate them with seafloor amplitude anomalies and fault traces in order to characterize seep activity level. The southern mud volcano in the Garden Banks site is characterized as an established high flux seep vent owing to signs of active seepage and sediment flows as well as the build-up of hard grounds. The northern mud volcano in the area, with greater hard ground build-up and fewer signs of active seepage represents an established low flux seep vent. In the Mississippi Canyon area, the data suggest that the seep mound can be characterized as a mature high flux vent due to the extensive build-up of hard ground, evidence of gas hydrates and signs of active seepage and sediment flows. The mechanisms of formation are similar between the two study sites. Upwelling salt appears to have fractured the sub-surface leading to the formation of fault induced depressions. Mapping of geophysical indicators of hydrocarbons implies that hydrocarbon migration is occurring along bedding planes to the fault systems underlying the depressions. Here they appear to migrate vertically to the seafloor creating the topographic features and seafloor amplitude anomalies that characterize the seepsen_US
dc.format.extent4113648 bytes
dc.format.extent81118 bytes
dc.format.mediumelectronicen_US
dc.format.mimetypeapplication/pdf
dc.format.mimetypetext/plain
dc.language.isoen_USen_US
dc.publisherTexas A&M Universityen_US
dc.subjectGulf of Mexicoen_US
dc.subjectseismicen_US
dc.subjecthydrocarbon seepsen_US
dc.subjectgeophysical dataen_US
dc.subjectfaultsen_US
dc.title3-D multichannel seismic reflection study of variable-flux hydrocarbon seeps, continental slope, northern Gulf of Mexicoen_US
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentOceanographyen_US
thesis.degree.disciplineOceanographyen_US
thesis.degree.grantorTexas A&M Universityen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelMastersen_US
dc.contributor.committeeMemberWatkins, Joelen_US
dc.contributor.committeeMemberBryant, Williamen_US
dc.type.genreElectronic Thesisen_US
dc.type.materialtexten_US
dc.format.digitalOriginborn digitalen_US


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