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 191 for “"last glacial"”.
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Modeling Neotropical Ecosystems during the Last Glacial Maximum
… present contexts with particular emphasis on the Last Glacial Maximum. The first project was focused on discerning the effects of low atmospheric carbon dioxide and temperature on the carbon exchange of a well-watered tropical forest using a canopy-scale ecophysiological model. The radiative …
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East African monsoon variability since the last glacial
… from a laminated lake sediment core spanning the last 25,000 years. Analyzing a monthly cleared sediment trap confirms the annual origin of the laminations and demonstrates that the varve-thicknesses are strongly linked to the duration and strength of the windy season. Given the modern control of …
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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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Tropical climate variability from the last glacial maximum to the present
… of tropical climate variability from the Last Glacial Maximum to the present. The temporal variability of two specific tropical climate phenomena is examined. The first is the position of the Intertropical Convergence Zone (ITCZ) in the Atlantic basin, which affects sea surface temperature …
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The paleoceanography of the Bering Sea during the last glacial cycle
… anaerobic oxidation of methane. The episodes lasted less than 1000 years and were spaced about 1000 years apart. During MIS3 at 55-20 ky BP in a core from 2209m water depth on Bowers Ridge, N. pachyderma (s.) and Uvigerina δ18O and δ13C show no coherent variability on millennial time scales. …
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Tropical climate variability from the last glacial maximum to the present
… of tropical climate variability from the Last Glacial Maximum to the present. The temporal variability of two specific tropical climate phenomena is examined. The first is the position of the Intertropical Convergence Zone (ITCZ) in the Atlantic basin, which affects sea surface temperature …
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The paleoceanography of the Bering Sea during the last glacial cycle
… anaerobic oxidation of methane. The episodes lasted less than 1000 years and were spaced about 1000 years apart. During MIS3 at 55-20 ky BP in a core from 2209m water depth on Bowers Ridge, N. pachyderma (s.) and Uvigerina 18O and 13C show no coherent variability on millennial time scales. …
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Micromorphology of Last Glacial Maximum Grounding line sediments around the Antarctic Peninsula
Sediments recovered from seven Last Glacial Maximum grounding lines sites, around the Antarctic Peninsula, were analyzed using micromorphology. This is the first evidence that grounding line sediments from around the Antarctic Peninsula have complex deformational histories and subglacial origins. …
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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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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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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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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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Comparative Phylogeography of Eastern Chipmunks and White -Footed Mice: Population Histories Since the Last Glacial Maximum
… sequences of all P. leucopus indicated that post-glacial expansions into the region did not confound the analysis of microsatellite variation. This study provides important empirical data on the importance of urban development in disrupting evolutionary processes within natural populations.
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Seafloor ploughmarks on the mid-Norwegian continental shelf reveal iceberg trajectories during the last glacial period
… LGM and throughout deglaciation. In Trænadjupet glacial trough, a strong unimodal ploughmark orientation to the northwest suggests an alternative forcing to the NwAC, here interpreted as the combined action of the Norwegian Coastal Current and bathymetric constraints imposed by the ice sheet …
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Distribution of post-Last Glacial Maximum Sedimentary Deposits in the Amundsen Sea, Antarctica, from Subbottom Seismic Profiles
… West Antarctica provide insight to geologic and glacial processes that have occurred across the continental shelf since the Last Glacial Maximum (~20 ka), as well as processes that are occurring today. Subbottom profiles collected across the Amundsen Sea Embayment during the austral summers of …
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Concentration and Size Distribution of Microparticles in the NGRIP Ice Core (Central Greenland) during the Last Glacial Period
… Preboreal Holocene and 8000 ¹g kg¡ 1 during the last glacial maxi-mum (LGM). Strong variations of the insoluble particle mass were encountered corresponding to the Dansgaard/Oeschger (D/O) events within the last glacial period, with concentration changes by typically a factor of 8 across the …
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Exploring mechanisms for the decrease of atmospheric CO₂ during the last glacial maximum using a four-box ocean model
A record of carbon dioxide for the last 400,000 years revealed that atmospheric CO2 decreased from a pre-industrial concentration of 280 ppmV to approximately 200 ppmV during the last glacial maximum (Petit et al., 1999). Several hypotheses as to why this happened have been suggested yet no one …
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The evolution of the Greenland Ice Sheet from the Last Glacial Maximum to present-day: An assessment using glaciological and Glacial Isostatic Adjustment modelling
… of Greenland ice sheet (GrIS) evolution from the Last Glacial Maximum (LGM, 21 ka BP) to the present-day using, primarily, observations of relative sea level (RSL) as well as field data on past ice extent. The new model (Huy2) fits a majority of the observations and is characterised by a number of …
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