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 62 for “"Last Glacial Maximum (LGM)"”.
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RECONSTRUCTING PAST ANTARCTIC ICE FLOW PATHS IN THE ROSS EMBAYMENT, ANTARCTICA USING SAND PETROGRAPHY, PARTICLE SIZE AND DETRITAL ZIRCON PROVENANCE
… were used to provide new information on the subglacial geology of Antarctica, as well as assisting in the reconstruction of Last Glacial Maximum (LGM) ice flow paths. Statistical analyses using the Kolmogorov-Smirnov (K-S test) reveal that EA and WA zircon age distributions are distinct at a …
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Inferring ocean circulation during the Last Glacial Maximum and last deglaciation using data and models
Since the Last Glacial Maximum (LGM, ~ 20,000 years ago) air temperatures warmed, sea level rose roughly 130 meters, and atmospheric concentrations of carbon dioxide increased. This thesis combines global models and paleoceanographic observations to constrain the ocean’s role in storing and …
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Inferring ocean circulation during the last glacial maximum and last deglaciation using data and models
Since the Last Glacial Maximum (LGM, ~ 20,000 years ago) air temperatures warmed, sea level rose roughly 130 meters, and atmospheric concentrations of carbon dioxide increased. This thesis combines global models and paleoceanographic observations to constrain the ocean's role in storing and …
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A 20,000 year flowstone record of Gulf of Mexico sourced moisture in Texas
… or Pacific Ocean sourced moisture since the Last Glacial Maximum (LGM) at cave sites across the Southwest. In this study, a new oxygen isotope time series is developed from a flowstone in central Texas as a means to test this hypothesis. Due to significant age reversals in the U-series …
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Climatic factors influencing Last Glacial Maximum and modern glacial conditions in the tropical and subtropical Andes
… subtropical Andes. Model results show average Last Glacial Maximum (LGM) equilibrium line altitude (ELA) depressions to be approximately 600 m in the tropics and 800 m in the subtropics, consistent with studies that suggest the subtropical Andes were glaciated at LGM. While previous studies …
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Evaluation of Paleo-climate for the Boise Area, Idaho, from the last Glacial Maximum to the Present Based on delta 2H and delta 18O Groundwater Composition
… surface temperature between the present and the last glacial maximum (LGM). The local temperature decreased 4-5 °C from the present to the LGM for the Boise area.</p>
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Submarine Geomorphology of the Continental Shelves of Southeast and Southwest Greenland from Olex Data
… our understanding of the extent, dynamics and deglacial retreat of the Greenland Ice Sheet during and after the Last Glacial Maximum (LGM), this study used geophysical bathymetric data to investigate the geomorphology of the continental margins of Southern Greenland. In particular, Olex data, …
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Western South Atlantic holocene and glacial deepwater hydrography derived from benthic foraminiferal Cd/Ca and stable carbon isotope data
… versus southern source water production. Last glacial maximum (LGM) Cd/Ca and δ13C data indicate a nutrient-depleted intermediate-depth water mass. In the mid-depth western South Atlantic, a simple conversion of LGM δ13C data suggests significantly less nutrient enrichment than LGM Cd/Ca …
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Western South Atlantic holocene and glacial deepwater hydrography derived from benthic foraminiferal Cd/Ca and stable carbon isotope data
… versus southern source water production. Last glacial maximum (LGM) Cd/Ca and 813C data indicate a nutrient-depleted intermediate-depth water mass. In the mid-depth western South Atlantic, a simple conversion of LGM 813C data suggests significantly less nutrient enrichment than LGM Cd/Ca …
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What do paleo-geochemical tracers tell us about the deep ocean circulation during the last ice age?
… Atlantic was enriched in nutrients during the Last Ice Age. The conventionally accepted interpretation of these higher nutrient levels is that a reduction of the rate of formation of nutrient-depleted Lower North Atlantic Deep Water (Lower NADW) allowed nutrient-rich Antarctic Bottom Water …
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The Evolutionary History of the Antarctic Flora
… were covered by thick ice sheets throughout the Last Glacial Maximum (LGM; ~22-18 kya) as well as previous glaciations, suggesting terrestrial life must have been extremely limited during these periods. In contrast, recent biogeographic and genetic studies support most extant groups of Antarctic …
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Glacial-interglacial variations of the water masses in the southeast Atlantic Ocean derived from foraminiferal neodymium isotope ratios
… It is now commonly believed that, during the Last Glacial Maximum (LGM), the transport of North Atlantic Deep Water (NADW) to the southeast Atlantic Ocean was reduced. A popular method to trace these ambient changes is the stable isotope systematics of neodymium (given as εNd). In this study …
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Atlantic Ocean circulation at the Last Glacial Maximum : inferences from data and models
… atmospheric forcing in the Atlantic Ocean at the Last Glacial Maximum (LGM, 18-21 thousand years before present). Relative to the pre-industrial climate, LGM atmospheric CO2 concentrations were about 90 ppm lower, ice sheets were much more extensive, and many regions experienced significantly …
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The Evolution of the El Niño-Southern Oscillation and Tropical Pacific Climate Across the Last Deglaciation
… to millennial-scale climate events over the last 25,000 years. Here, I present new records of tropical Pacific mean state and ENSO variability over the last 25,000 years reconstructed from a high-resolution sediment core recovered from the Eastern Equatorial Pacific (EEP) cold tongue …
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The demography of Red Sea reef fishes since the Last Glacial Maximum
… many reef fish populations persisted during the Last Glacial Maximum despite a significant loss of coral reefs. I studied their demogaphic history to determine the impact of environmentally-induced habitat loss. High-throughput sequencing data combined with an Approximate Bayesian Computation …
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Atlantic Ocean circulation at the last glacial maximum : inferences from data and models
… atmospheric forcing in the Atlantic Ocean at the Last Glacial Maximum (LGM, 18-21 thousand years before present). Relative to the pre-industrial climate, LGM atmospheric CO₂ concentrations were about 90 ppm lower, ice sheets were much more extensive, and many regions experienced significantly …
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Late Quaternary and Holocene Paleoecology of Interior Mesic Forests of Northern Idaho
… within the inland disjunction survived the glacial periods of the Pleistocene, or whether they were more recently dispersed from coastal populations. To see if the dominant tree taxa of the mesic forests today could have persisted in a refugium south of the large ice sheets, four sediment …
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Sedimentation on a mixed siliciclastic/carbonate continental margin over decadal to millennial timescales: Gulf of Papua
… in sediment mass accumulation rates during post-Last Glacial Maximum (LGM) sea level rise. Upper 12 m of the sediment on the northeastern shelf edge has deposited in < 12 ky BP after post-LGM sea level rise. The bulk of this mud deposit, with mass accumulation rates as high as 3900 g cm-2 ky-1, …
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Constraining circulation changes through the last deglaciation with deep-sea coral radiocarbon and sedimentary 231Pa/230Th
… the ocean’s role in climate change over the last deglaciation. I present a new method for rapid radiocarbon analyses as a means of age-screening deep-sea corals for further study. Based on age survey results, I selected forty corals from the Drake Passage and thirteen from the Reykjanes Ridge …
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The Antarctic Peninsula ice sheet since the Last Glacial Maximum
… and configuration of the ice sheet during the Last Glacial Maximum (LGM), an important issue for quantifying post-LGM sea level rise and providing boundary conditions for General Circulation Models. Geomorphic features analyzed in multibeam swath bathymetry and seismic data from the 2002 cruise …
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