Biogenic “oozes” are pelagic sediments that are composed of > 30% carbonate microfossils and are estimated to cover about 50% of the ocean floor, which accounts for about 67% of calcium carbonate in oceanic surface sediments worldwide. These deposits exhibit diverse assemblages of planktonic microfossils and contribute significantly to the overall sediment supply and function of Florida’s deep-water regions. However, the composition and distribution of biogenic sediment deposits along these regions remains poorly documented. Seafloor surface sediments have been collected in situ via Johnson- Sea-Link I submersible along four of Florida’s deep-water regions during a joint research cruise between Harbor Branch Oceanographic Institute (HBOI) and Florida Atlantic University (FAU). Sedimentological analyses of the taxonomy, species diversity, and sedimentation dynamics reveal a complex interconnected development system of Florida’s deep-water habitats. Results disclose characteristic microfossil assemblages of planktonic foraminiferal ooze off the South West Florida Shelf, a foraminiferal-pteropod ooze through the Straits of Florida, and pteropod ooze deposits off Florida’s east coast. The distribution of the biogenic ooze deposits is attributed to factors such as oceanographic surface production, surface and bottom currents, off-bank transport, and deep-water sediment drifts. The application of micropaleontology, sedimentology, and oceanography facilitate in characterizing the sediment supply to Florida’s deep-water regions. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

The objective of this project is to develop a shape-based image analysis system, which allows classification and identification of holographic images of marine particles and plankton recorded by an underwater digital holographic camera. In order to achieve this goal, the first step is to extract shape regions of objects from images and to describe the regions by polygonal boundaries. After extraction of the polygonal boundary curve of an object, affine-invariant curve normalisation is implemented on the curve to reduce the influence of object shape deformations on object identification and classification. Six numeric features are then selected to describe shape properties of an object. Before these six shape features are used as a numeric interpretation of an object for image analysis, some processing of them is necessary, consisting of selecting the number of items in each feature and rescaling the selected feature vectors. Afterwards, Gaussian rescaling is adopted to rescale the feature data. Lastly, a shape-based image classification and identification system is built. The system contains two components: semi-automatic image classification (imCLASS) and automatic image identification (imIDENT). In imCLASS, an image retrieval method based on the support vector machine with a feedback mechanism has been developed. The function of imCLASS is to classify given images into different folders with the corresponding labels from the user. These labelled folders can be used to train the artificial neural network in imIDENT. A set of analyses of effects of the proposed methods in the process chain on image analysis are carried out. The whole performance of the system for classifying and identifying marine particles and plankton is also evaluated in terms of the time-cost and accuracy performance. In the end, some main conclusions are listed. The areas of weakness of the system are also highlighted for future work.

The distribution of surface sediments on the northern Oregon continental shell is characterized by a nearshore sandy facies and an outer shelf muddy facies, separated by a mid-shelf zone of mixed sand and mud. Currents which have been measured at 130 centimeters above the bottom indicate that the distribution of the surface sediment is a reflection of the hydraulic regime. The strongest bottom currents which were measured were in the nearshore region at a depth of 36 meters. Here currents of over 40 cm/sec generated by surface waves are capable of placing the nearshore sands in suspension, where they are transported shoreward by the wave surge. At mid-shelf, in 90 meters of water, the bottom current veolcity ranges from zero to over 25 cm/sec, although the mean is normally about 10 cm/sec. The strongest currents at this depth are capable of eroding some of the fine sediments, but probably do not rework the older sediments which have been compacted. Currents which are similar in character to those at mid-shelf were observed at the shelf edge in a depth of 165 meters. A significant departure, however, is the difference in frequency where the most energy is found. At the shelf edge the dominant frequency was about four cpd whereas the dominant frequency at mid-shelf was two cpd or lower. The dominant frequencies indicate that tides are important in the generation of continental shelf bottom currents. The twelve - hour period is that of the semi-diurnal tide; the six-hour period is the second harmonic of the semi-diurnal component. No indication of surface wave influence was found at mid-shelf or shelf-edge depths. Profiles of turbidity made at four east-west transects of the continental shelf indicate suspended sediment transport occurs principally at three levels in the water column. An upper layer is at the level of the seasonal thermocline, a mid-water layer is located at the level of the permanent pycnocline, and the third layer is at the bottom. The surface layer is important in transporting suspended sediment of the Columbia River plume, although there is also a contribution to the surface layer from the surf zone by the process of diffusion of fine particles. The mid-water layer thickens vertically and becomes less intense seaward, indicating a nearshore source for the suspended material. This source is diffusion of fine particles from the surf zone at mid-water depths. The mid-water layer is located at the level of the permanent pycnocline. The layer is sub-parallel to the bottom over the shelf but becomes diffuse at the shelf edge. Sediment transport in the mid-water layer provides a mechanism by which sediment bypasses the outer shelf and upper slope area. The bottom layer receives its suspended material from erosion of the bottom, from the water column above, and from fine material moving seaward from the surf zone. The amount of eroded material contributed to the bottom layer depends on the bottom current strength and on the bottom roughness characteristics. Over a rough bottom the erosive power of a given bottom current is increased drastically. For this reason, the presence or absence of rippling is important to sediment transport on the shelf. The fine material of the bottom layer may concentrate by settling during quiescent periods, allowing low-density flows to initiate. Several time-series observations of turbidity indicate that the bottom layer thickens and thins in response to increases and decreases in current velocity. The mid-water layer migrated somewhat in a vertical direction, but its thickness and intensity remained nearly the same. The thickness and intensity of the upper layer responded to changes in the structure of the thermocline, becoming thick and dispersed when the upper part of the water column is mixed. A model of sediment transport proposes that mid-water and bottom currents transport suspended sediments diagonally across the shelf toward the south-southwest. The sediments of the Columbia River plume are also transported in a southerly direction in the surface waters. Relatively little deposition takes place on the shelf and upper slope, with the bulk of the sediments bypassing the shelf and depositing on the lower slope and continental rise. / Graduation date: 1972

A systematic study of highly branched isoprenoids (HBI) was carried out in suspended particulate material (SPM) and Washington coastal sediments to determine their origin and fate. SPM collected at 10 m depth was filtered through Nitex membranes. C₂₅ HBI were found only in the 1.2-40 μm range over the shelf. The particle size fractionation of SPM shows different enrichment for HEH, a common hydrocarbon in phytoplankton, and the sum of C₂₅ HBI in the finer fractions suggesting these hydrocarbons do not share a common source. The distribution of C₂₅ and C₃₀ HBI correlates with the chlorophyll maxima suggesting an upper-water microbial source associated with phytoplankton biomass. It has been hypothesized that sulfur addition into specific biomarkers occurs during the early stages of diagenesis. Incorporation of the HBI into a refractory geomacromolecule via a sulfur linkage or formation of HBI-thiophenes are not evident in the sedimentary lipids. HBI show a rapid decrease in concentration with depth in both midshelf and slope sediments suggesting that biodegradation is the major pathway for their disappearance in Washington coastal sediments. Sediment cores from a midshelf and slope locations show the existence of suboxic/anaerobic conditions within the first 5 cm in the sediments. Elemental sulfur distribution in the midshelf appears to be controlled by bioturbation. On the slope, its profile indicates a quasi steady state regime. Phytane and phytenes (∑Phy) are the major products of Raney nickel desulfurization in both midshelf and slope sediments. Spinach and a strain of Emiliana huxleyi treated with Raney nickel showed strikingly similar patterns to the desulfurization products of sedimentary lipids. The amount of ∑Phy in the slope decreases abruptly by a factor of 6 in the top 2 cm and gradually increases with depth. These results are interpreted as phytyl coming from two sources: (1) chlorophyll-a and (2) S-bound to geomacromolecules. Partial released of phytyl moieties from chlorophyll-a warrants a reevaluation of Raney nickel as a selective desulfurizing agent before its application for paleoenvironmental reconstruction. Reducing micro-environments appear to exist within the bioturbated zone in shelf sediments. However, there is no clear evidence for phytyl moieties S-linked to macromolecules within the mixed layer. Results obtained during this study indicate that sulfur incorporation to biomarkers, although present, does not represent a significant mechanism for the preservation of organic carbon in normal marine sediments. / Graduation date: 1994

Graduation date: 1998

Thesis (Sc. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1983. / Cover title: Flow and skin friction over natural rough beds. Includes bibliographical references (p. 325-333).

Thesis (M.Sc.)--Memorial University of Newfoundland, 2006. / Bibliography: leaves 238-247. Also available online.

Thesis (M. Sc.)--College of William and Mary. / Typescript (photocopy). Vita. Includes bibliographical references (leaves 96-100).

Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2002. / Vita. Includes bibliographical references (leaves 153-161).

Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : [55]-[60]).