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<p> The export of particulate carbon from the surface ocean into deeper water and to the seabed is a critical component of the carbon cycle. The concentrations and compositions of particulate pigments collected at different depths and sinking at different settling velocities can be used as a proxy for biologically mediated processes important to the early degradation of OM. By knowing what processes the compositional and quantitative changes in the particulate pigments represent, the POM cycle of the BaRFlux area can be better understood. It is important to understand the POM cycle because deposition of OM to the seabed is the only way that OM is sequestered. The removal of POM from the marine POM cycle is especially important to understand in subtropical gyre areas like the BaRFlux site because: 1. subtropical gyres are areas of downwelling, and therefore POM transport to the deep ocean and may increase as global warming continues. 2.the flux of CO₂ to the ocean is increasing from rising levels of atmospheric CO₂, and CO₂ removed by the biological pump will lessen processes like ocean acidification.</p><p> This thesis examines the early degradation of chloropigments in the sediment and water column in the Bermuda Rise area of the Sargasso Sea. Water column particulate samples were collected with in-situ pumps, Niskin bottles, and Indented Rotating Sphere (IRS) sediment traps, and sediment was collected by box cores during 2011-2013 to record seasonal patterns in quantity and quality of particulate pigments as a function of water column depth and particle size. Chl-a, Chl-b, and pheopigments were separated and quantified using reverse-phase High Performance Liquid Chromatography (HPLC).</p><p> The comparison of data from in-situ pumps and Niskin bottles indicates that collection method significantly affects particulate pigment data concentrations. Niskin bottle data showed total pigment concentrations 10 times greater than in-situ pump pigment concentrations at shallow depths. At depths below the euphotic zone, Niskin bottle and in-situ pump concentrations both appear similar because the particulate pigment concentrations were below the detection limit. For the BaRFlux study area, the differences in Niskin bottle and pump data are most likely from: 1. the biased particle distribution due to sampling a small volume of seawater with Niskin bottles in an area of dilute particle concentration; 2. the greater retention efficiency of picophytoplankton on Niskin GF/F filters than 1-<i>&micro;</i>m in-situ pump microquartz filters.</p><p> The compositional changes seen in small suspended particulate pigments over depth is consist with small suspended particles being consumed by shallow water zooplankton and then increasingly altered by microbial activity with increasing depth. The composition of small and large particulate pigments were compared to determine if aggregation-disaggregation was an important process. Larger suspended particulate pigments were nearly 100% Chl-a over depth and distinct from smaller suspended particulate pigments other than samples from May or June, during which particle exchange may be more important. The comparison of particulate pigment data to CTD beam transmissivity profiles suggests that the nepheloid layer consists of small suspended particulate matter rather than large particles.</p><p> Sediment trap samples were compositionally enriched in pheopigments relative to smaller bottle and pump samples, indicative of enrichment with more rapidly sinking larger zooplankton fecal pellets. The mole% of chlorophyll-a labile pigment increased with increasing settling velocity, suggesting aggregation may increase the settling velocity of particles enough to escape zooplankton feeding. The particulate pigment composition of seafloor sediment collected in August was compositionally distinct from that of suspended and sinking particulate pigments and was nearly 100% pheophorbide-a, indicating POM degradation by feeding macrobenthos.</p>

This dissertation presents the detailed results of investigations of the geomorphological and sedimentary processes associated with five Holocene tsunamis reported to have occurred in the Aegean Sea region of Greece. This research considers the effects of the widely quoted and archeologically important Minoan tsunami of the 17th century B.C.; the central southern Aegean tsunami of 66 A.D.; a hugely destructive tsunami reported to have followed a massive earthquake on the 21st July 365 A.D.; a tsunami of volcanic origin which affected the island of Thira on 29th September 1650 A.D.; and the destructive southern Aegean tsunami of 9th July 1965 A.D. The last account is believed to be the first systematic investigation of the geomorphology and sedimentology of a modern Aegean tsunami. This research is primarily concerned with the investigation of Holocene coastal sedimentary sequences in order to identify any geological traces of the former tsunamis and it is hoped that this evidence can be used to supplement the fragmentary historic accounts. This dissertation also considers whether microfossils can be used in the identification of individual stratigraphic horizons associated with tsunami-deposited sediments and investigates whether it is possible to determine the generative origins of individual tsunamis on the basis of the sediments associated with them. Whilst the findings of this research are not intended to provide a definitive account of the tsunamis considered, they do provide important evidence where the prevailing geological conditions of the Aegean Sea region would otherwise combine to limit the data available. Furthermore, it is believed that the results of this investigation do contribute to existing knowledge and will be of value to archaeologists seeking to explore the relationships between archaeological sites, landscape evolution and environmental change.

Differential compaction occurs within many sedimentary settings, such as alluvial and deltaic deposition, but it is within the submarine fan environment where the process is most effective due to the very high depositional porosities of the muds found there. Additionally the grain size of siliciclastic sediments within the submarine fan environment varies rapidly both horizontally and vertically, and hence the effect of differential compaction control on the depositional geometry and arrangement needs to be examined and modelled. It is also important to ascertain the rate at which sediments compact when buried, and whether compaction is complete at the end of deposition or whether it requires additional time to achieve this state. Sea- floor topography can be created if the latter case is true, and could influence subsequent deposition. Alternatively, if sea-floor topography is not created, the major control upon subsequent deposition may be the compatibility of the underlying section. Both controls will favour deposition of successive coarse clastic units above areas of fine-grained sediments, i.e. sand above shale rather than sand above sand. The Palaeocene sediments of the Central North Sea In the Montrose - Arbroath area (Blocks 22/17 and 22/18) combined with outcrop studies In southern California and New Mexico, have been used to assess the control of differential compaction on sediment distribution in a deep-sea fan setting. Differential compaction affects the Montrose - Arbroath area on a variety of scales. Firstly, differential compaction of the entire Palaeocene section across the underlying Forties - Montrose High induces structure. At a smaller scale, differential compaction may form a considerable control upon the spatial distribution of submarine fan channels and lobes that form the reservoir section throughout the area, and therefore the areal distribution of the oilfields themselves. Finally differential compaction may effect the distribution pattern of individual turbidites within such channel systems, thus forming a fine control upon the distribution of sands and shales within the reservoir. Fieldwork on submarine fan deposits in southern California has highlighted further complications to differential compaction that need to be addressed during the modelling process. Sedimentary processes such as basal loading and slumping are highly common in such deposits, and both can effect the compactional process to differing degrees. Results obtained from the modelling of stratal patterns observed in New Mexico provide information on the timing of differential compaction. It is suggested that compaction of sediments, even during early burial, requires a time interval often greater than the period of deposition, resulting in post-depositional compaction and the production of near-surface overpressure.

Thesis (M.S.)--University of Montana, 2008. / Title from title screen. Description based on contents viewed Aug. 20, 2008. Includes bibliographical references (p. 43-49).

Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). One folded sheet in pocket. Includes bibliographical references (leaves 126-134). Also available via the World Wide Web.

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1913. / The entire thesis text is included in file. Typescript. Some illustrations by author. Title from title screen of thesis/dissertation PDF file (viewed April 30, 2009) Includes bibliographical references.

Thesis (Ph. D.) -- l'Université de Rennes, 2007. / "Thése de Doctorat de l'Université de Rennes 1 réalisée en co-tutelle avec l'Université de Canterbury (Christchurch, Nouvelle-Zélande)." "Soutenue le 9 novembre 2007." Includes bibliographical references. Also available via WWW.

Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). "Ph.D. thesis realized in cotutelle with the University of Rennes 1, Rennes, France." Includes bibliographical references. Also available via the World Wide Web.