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 19 of 19 for “"Sediment records"”.
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Reconstructing late Holocene Artctic climate change using high resolution sediment records from Simpson Lagoon, Alaska and the Colville River alluvial valley
… Alaska, potentially contain high-resolution sediment archives that can be utilized to reconstruct paleoclimate variability over the late Holocene. The ongoing, rapid environmental changes recently observed in the Arctic highlight the need for high-resolution records of pre-industrial climate …
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Late Pleistocene-Holocene sedimentary processes at the active margin of South-Central Chile : marine and lacustrine sediment records as archives of tectonics and climate variability
… both processes, I examined marine and lacustrine sediments from different depositional environments on- and offshore the south-central Chilean coast (38-40°S). I combined sedimentological, geochemical and isotopical analyses to identify climatic and tectonic signals within the sedimentary records. …
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An investigation of lead and other metal contaminants in the sediments of Clearwater Lake, Missouri
… and concentration of trace metals in sediments of Clearwater Lake. Understanding how trace metals are released to and transported in aquatic environments is important to the overall understanding of the impacts of mining on the natural environment. The main focus of this research will …
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Lacustrine Sediment Record of Multiple Quaternary Lava Dams on the Owyhee River, Southeastern Oregon
… the Quaternary evolution of the Owyhee River. Sediment records from lava-dammed lakes were investigated to understand effects of the West Crater (WC) lava dam (~70 ka), the Saddle Butte 2 lava dam (~144 ka), and the Bogus Rim lava dam (~1.9 Ma). Evidence from the WC lava dam and related …
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Lake and fjord sediments as Late Glacial to Holocene environmental and climate archives of the southernmost Andes at 53°S, Chile
… sites on the basis of parametric echo sounding sediment profiles in the fjords of the Gran Campo Nevado area. The stratigraphy of the sediment cores is based on 14C-AMS ages and tephrachronology. Sedimentological and geochemical characteristics were investigated in order to determine sediment …
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A biogeochemical investigation of Trunk River Lagoon, Falmouth, Massachusetts
… within Trunk River Lagoon, encompassing sediments, microbial blooms, and mats. Through a multi-faceted approach, the research uncovers the interplay between natural processes and anthropogenic influences, shedding light on the evolutionary trajectory of this aquatic ecosystem. From …
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The palaeolimnological record of regime shifts in lakes in response to climate change
… the imprints they leave in palaeolimnological records allow us to investigate and better understand patterns and processes governing ecological changes on geological time scales. This thesis aims at investigating palaeolimnological records of regime shifts in lakes during the Holocene to …
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Late Quaternary climate variability and terrestrial carbon cycling in tropical South America
… plant biomarkers in lacustrine and marine sediment cores to explore late Quaternary climate variability and connections between past climate change and terrestrial carbon cycling in tropical South America. I investigate temporal and spatial trends in South American Summer Monsoon …
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Late Quaternary climate variability and terrestrial carbon cycling in tropical South America
… plant biomarkers in lacustrine and marine sediment cores to explore late Quaternary climate variability and connections between past climate change and terrestrial carbon cycling in tropical South America. I investigate temporal and spatial trends in South American Summer Monsoon …
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Explosive Volcanism in the Kenyan Rift: A Tephrostratigraphic Perspective
… incomplete and poorly dated or correlated. Lake sediment records offer an opportunity to establish more comprehensive records of volcanism. In this study, two ~Holocene sediment core sequences, Lake Chala (Tanzania) and Lake Naivasha (Kenya), are investigated for the presence of cryptotephra …
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Holocene guano influences on eutrophication and lacustrine ecology at Kettle Lake, North Dakota
… stable nitrogen isotope values (𝛿15N) from lake sediment organic matter, with particular focus on periods of struvite deposition, a magnesium-ammonium-phosphate mineral formed from guano. I find that 𝛿15N is elevated throughout the Holocene in comparison to other lake sediment records in North …
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Geochemistry of karst deposits in Borneo detailing hydroclimate variations in the Warm Pool across the late Pleistocene
… of robust climate projections. Most paleoclimate records, however, still lack the resolution, length, and chronological control to resolve rapid variability against a background of orbital-scale variations. Here we present stalagmite oxygen isotope (δ18O) reconstructions from Gunung Mulu National …
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Reconstruction of recent and palaeo sea ice conditions in the Barents Sea
… sea ice diatoms that, when detected in marine sediments, has been used as a proxy for past Arctic sea ice over the last decade. In the current study, the structure of this biomarker was determined following large-scale extraction from sediment material collected from the Canadian Arctic. After …
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Reconstruction of aspects of Northern New Zealand paleoclimate over the last 200 ka using laminated Auckland maar lake sequences
Continuous lake sediment records spanning two glacial cycles are rarely available from the Southern Hemisphere mid-latitudes, let alone with the requisite resolution and robust chronological control required to optimise paleoenvironmental reconstructions. In this context Onepoto maar paleolake in …
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Lateglacial to Holocene climatic and environmental changes in Europe : multi-proxy studies on lake sediments along a transect from northern Italy to northeastern Poland
Sediment records of three European lakes were investigated in order to reconstruct the regional climate development during the Lateglacial and Holocene, to investigate the response of local ecosystems to climatic fluctuations and human impact and to relate regional peculiarities of past climate …
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Late glacial and Holocene marine geology, palaeoceanography and palaeoecology of the Northern Isles of Scotland
… the northwestern North Sea has experienced low sediment accumulation rates, inhibiting the investigation regional palaeoenvironmental change using traditional marine sediment proxies. However, on the DY150 research cruise (2022), marine sediment cores were recovered from depositional basins …
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Holocene climate and environmental variability in NE Germany inferred from annually laminated lake sediments
… in NE Germany based on annually laminated lake sediments. The work contributes to the ICLEA project (Integrated CLimate and Landscape Evolution Analyses). ICLEA intends to compare multiple high-resolution proxy records with independent chronologies from the N central European lowlands, in order …
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Thermokarst dynamics in central-eastern Beringia
… can hardly be resolved by instrumental records covering modern time scales. However, long-term environmental variability is recorded in paleoenvironmental archives. Lake sediments are important archives that allow reconstruction of local limnogeological processes as well as past …
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A Reconstruction of Precipitation and Hydrologic Variability on the Peruvian and Bolivian Altiplano During the Late Quaternary
… have been observed in multiple paleoclimate records, including drill core records and paleo-lake level records, as apparent advances and retreats of large lakes in the terminal basin occupied by the Salar de Uyuni and the Salar de Coipasa. </p><p>Presented here are the results from three …