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 “"marine geophysics"”.
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Potential applications of magnetic gradients to marine geophysics
… Institute of Technology, Dept. of Geology and Geophysics, 1967.
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Ocean bottom seismic scattering
Seismic studies of the oceanic crust, both experimental and theoretical, often assume a flat seafloor and laterally homogeneous crust. This is done regardless of the appearance in seismic data of obvious effects due to scattering from lateral heterogeneities both on and in the seafloor. Detailed …
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Reconstructing atmospheric changes in Monsoon regions using eolian dust
Mineral dust is generated in continental interiors and exported by winds to ocean basins, providing a sedimentary archive which is one of the few direct indicators we have of atmospheric circulation in the past. This archive can be utilized in regions of dust transport also affected by monsoons to …
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A study of the seismic structure of upper oceanic crust using wide-angle reflections
… This method has not been applied to deep sea marine data before; it gives a more detailed velocity structure of the sediments than does a traditional study of the basement reflections' travel-times. Second, the same data are mapped into tau-p space in order to measure the velocity gradient in …
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The tectonic evolution of the North Central Caribbean plate margin
The results of a detailed geophysical survey are used in conjunction with all available information in a study of the tectonic development of the Cayman Trough and the Greater Antilles Ridge. This development is connected with the relative motions of the North and South Americas and the eastern …
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The crustal structure and subsidence history of aseismic ridges and mid-plate island chains
This thesis consists of three papers examining problems related to the crustal structure, isostasy and subsidence history of aseismic ridges and mid-plate island chains. Analysis of gravity and bathymetry data across the Ninetyeast and eastern Walvis Ridges indicates these features are locally …
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Applications of time series analysis to geophysical data
This thesis consists of three papers applying the techniques of time series analysis to geophysical data. Surface wave dispersion along the Walvis Ridge, South Atlantic Ocean, is obtained by bandpass filtering the recorded seismogram in the frequency domain. The group velocity is anomalously low in …
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The gravity field and plate boundaries in Venezuela
Free-air and simple Bouguer anomaly maps of the Venezuelan continental margin (from 60°W to 72°W and from 7°N to 13°N) are presented. The major features of the free-air map are: the large lows associated with the deep sedimentary basins, -200 mgal in the Eastern Venezuela basin and -164 mgal in the …
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Analysis and pattern mapping of organic interfaces by means of seismic geophysical technologies to investigate archaeological palaeolandscapes beneath the Southern North Sea
… This research supports the search for peat in submarine environments by interpreting seismic surveys of the sub-sea floor and analysing reflective signals for distinctive organic responses. By means of sedimental analysis and ground observation, the research sets out to differentiate between …
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Volcanic deformation as an indicator of mechanical stability and eruption susceptibility
… in New Zealand, and recent eruptions of the submarine volcano, Axial Seamount. I address the effect of tectonic stresses on triggering the eruption of the Taupo Caldera, and reveal that mechanical stability of shallow, silicic magmatic systems are intrinsically linked to tectonic setting. For …
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Mechanisms of heat transport through the floor of the equatorial Pacific Ocean
The equatorial Pacific heat flow low, a major oceanic geothermal anomaly centered on the equatorial sediment bulge, was investigated using deeply penetrating heat flow probes (6-11 meters penetration) within three detailed surveys (400 km2) and along over 10,000 km of continuous seismic profiles …
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The Quaternary evolution of the mid-Norwegian continental margin
… streams on the adjacent shelves. Second, submarine glacial landforms found on the 500-km long mid-Norwegian continental shelf allow the reconstruction of the ice-sheet configuration over several Quaternary glacial–interglacial cycles. Evidence of iceberg ploughmarks found within the earliest …
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Iceberg-keel ploughmarks on the seafloor of Antarctic continental shelves and the North Falkland Basin: implications for palaeo-glaciology
… ice-cliff structural collapse and calving by marine ice-cliff instability (MICI) processes. Thus, ploughmarks provide the first observational evidence of rapid retreat of the palaeo-Pine Island-Thwaites ice stream, driven by MICI processes commencing ~12.3 cal ka BP. On the Weddell Sea shelf, …