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 20 of 20 for “"Deep Sea Sediments"”.
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An experimental study of compressional velocities in deep sea sediments
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1960.
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Reflection of seismic waves at oblique angles from deep sea sediments
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1964.
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Determination of Amino Acid-N in Deep-Sea Sediments and the Relationship Between Amino Acid Levels in Three Cores From the Argentine Basin and Past Climatic Changes
Made available in DSpace on 2014-12-10T17:12:41Z (GMT). No. of bitstreams: 1 6915282.pdf: 3548143 bytes, checksum: ce558e3d20b91acba4b34513af9c9eb0 (MD5) Previous issue date: 1969
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The Effect of Historic Shipwrecks on Sediment Microbiomes in the Northern Gulf of Mexico
… methane seeps, wood falls, octocoral, and deep-sea sediments. However, it was unknown if the presence of man-made structures on the seafloor, including historic shipwrecks, also resulted in a distinct core microbiome. To determine how historic shipwrecks impact sediment microbiomes under …
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Expansion of Deltaproteobacteria diversity from marine sediment reveals unique metabolic features
… genomes (MAGs) from a variety of coastal and deep-sea sediments. These 402 Deltaproteobacteria MAGs represent a 28% increase in Deltaproteobacteria genomes. Phylogenomic analyses revealed 12 novel lineages which consist entirely of uncultured representatives. Among these are two lineages that …
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Plutonium isotopes in the North Atlantic
… technique for the analysis of Pu in marine sediments, pore waters, sediment trap material and sea water from the North Atlantic. With the m.s. technique, not only is the detection limit for 239,240Pu increased by over an order-of-magnitude, but the 240Pu and 239Pu isotopes can be separated …
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Pliocene-Pleistocene Radiolarian Investigations of the Equatorial Oceans
… to the investigation of Late Cenozoic deep-sea sediments recovered by the Deep Sea Drilling Program (DSDP) and Ocean Drilling Program (OOP), and utilizes these advances in undertaking a detailed palaeoenvironmental study of the Plio-Pleistocene Olduvai magnetosubchron (1.95-1.79Ma) of …
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The Evolution and Impact of Weddell Sea Deep Water
… Sheet is largely marine based and grounded below sea level, which makes it especially vulnerable for sea-level forcing and ocean warming. In turn, the Southern Ocean overturning circulation is partially driven by deep water formation along the Antarctic continent, which is strongly modulated by …
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Deep sea seismic stratigraphy
… for the reflection of seismic waves within deep-sea sediments are shown to be less reliable for the purposes of correlation than their counter-parts in shallow margin sequences. Similar surfaces, such as abrupt lithological changes and unconformities, in the two different realms are not …
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Variations in the particulate flux of ²³⁰Th and ²³¹Pa and paleoceanograhpic applications of the ²³¹Pa/²³¹Th ratio
… matter collected with sediment traps and in deep-sea sediment cores. New analytical methods for uranium, thorium, and protactinium isotopes by Inductively-Coupled Plasma Spectrometry (ICP-MS) with a conventional Meinhard concentric glass nebulizer were developed. Composite samples from …
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Assessing the impact of multiple environmental stressors on Atlantic Ocean deep-sea sediment ecosystems functioning.
Earth is a blue planet, and the deep seafloor covers more than 60% of its surface, with the greater majority comprising of soft sediments. Deep soft sediments host a unique and diverse seafloor community and are of major importance to global biogeochemical cycles. As the ocean acts as a major …
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Orbital and Suborbital Climate Variability during the Pliocene Intensification of Northern Hemisphere Glaciation
… MIS, 101-95), using proxy<br/>methods applied to deep-sea sediments in the equatorial oceans and the North Atlantic. In this<br/>way, I evaluate the forcing mechanisms, biogeochemical cycles and climate implications during<br/>the late Pliocene.<br/>In Chapter 2, palaeoproductivity is …
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Dating and Interpretation of Secondary Carbonate Deposits from the Last Interglacial
… for climatic shifts by most paleoclimate researchers. A better correspondence is achieved by comparing the growth phases with the flux of Galactic Cosmic Rays reconstructed from deep sea sediments. These are probably affecting the condensation processes in clouds and accordingly, the Earth’s …
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Tracing past and present Arctic geochemical cycling and its link to climate change using neodymium isotopes
… crustal evolution and in sediment and seawater provenance studies. In this thesis εNd is measured on a suite of marine and terrestrial sediment and waters, broadly focused on the circum-Arctic region, providing insights into both past and current water and sediment sources. A large …
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The geochemistry and geomicrobiology of relict hydrothermal sulphide deposits
The diagenetic re-mineralisation of seafloor-sulphide deposits and the role of microbes in the metal-exchange processes were investigated in metalliferous sediments from the Alvin relict hydrothermal zone in the TAG area at 26º8'N (Mid-Atlantic Ridge). The solid-phase and concomitant pore water …
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Methane Gas Hydrate Morphology and its Effect on the Stiffness and Damping of some Sediments
Gas hydrates are ice–like compounds found in deep sea sediments and permafrosts. Concise detection<br/>and quantification of natural methane gas hydrate deposits, will allow for a more robust assessment<br/>of gas hydrate as a potential energy resource or natural geohazard. Current seismic methods, …
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Characterisation of diverse microbial communities and application of novel detection techniques
… They are found in all viable habitats from deep sea sediments and bedrock to high up in the atmosphere with a variety that exceeds by far the eukaryotic diversity. Ecosystem services provided by microorganisms, such as degradation of organic material and mediation of biogeochemical cycles …
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Landscape evolution and preservation of ice over one million years old quantified with cosmogenic nuclides 26Al, 10Be, and 21Ne, Ong Valley, Antarctica
… Cenozoic are recorded in the ice sheet itself, deep sea sediments, and glacial deposits on the continent (Ingólfsson, 2004). Quaternary continental records of AIS extent is limited to few locations along the Transantarctic Mountains (TAM) and coastal continental boundaries (Denton et al., 1984; …
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Boron in Foraminiferal Calcite as an Indicator of Seawater Carbonate Chemistry
… whose physical and chemical nature reflect the seawater conditions in which they grow. Thus, fossil tests preserved on the sea floor represent an archive that may be used to investigate the composition of ancient seawater. With the aim of improving our understanding of past ocean-climate links, …
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From Continental Margins to the Deep Ocean
… indicators of bottom-water redox. In pelagic sediments, δ98Mo is not preserved over long timescales and can be altered by hydrothermal input. In the Guaymas Basin, high FeHR/FeT reflects diagenetic pyritization rather than euxinic conditions. On the Peruvian Margin, elevated FeHR/FeT and U …