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 31 for “"last glacial period"”.
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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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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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On the external forcing of Indian Ocean climate variability across timescales
… northern Madagascar which spans the end of the last glacial period. Stable isotope and trace metal proxies indicate drier conditions in response to North Atlantic cooling events, such as Heinrich stadials, and wetter conditions during North Atlantic warming events, such as the Bølling–Allerød. …
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On the external forcing of Indian Ocean climate variability across timescales
… northern Madagascar which spans the end of the last glacial period. Stable isotope and trace metal proxies indicate drier conditions in response to North Atlantic cooling events, such as Heinrich stadials, and wetter conditions during North Atlantic warming events, such as the Bølling–Allerød. …
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Late quaternary valley fill sediments in the River Tyne valley: Understanding late Devensian deglaciation and early postglacial response in northern England
This thesis reconstructs part of the deglacial and early post-glacial history of the River Tyne Valley, Northumberland. Data has been gathered through description and interpretation of sedimentary sequences and stratigraphies from quarry and cut-bank exposure, the development of a geochronology was …
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Geochemical tools and paleoclimate clues : multi-molecular and isotropic investigations of tropical marine sediments and alpine ice
… climate has undergone dramatic changes since the last glacial period, as evidenced from Cariaco Basin (Venezuelan coast) and Peru Margin marine sediment biomarker records. Compounds derived from vascular plant leaf waxes and delivered to the marine sedimentary environment, including long-chain …
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Submarine Landforms and Late Quaternary Ice Flow in Hinlopen Strait, Northern Svalbard Margin
… on the Northern Svalbard margin. During the last glacial period, this trough is thought to have been occupied by an ice stream which flowed north across the continental slope (Ottesen et al., 2007). This project is concerned with examining the submarine landforms and acoustic stratigraphy of …
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VOLCANIC EMISSIONS AND DISTAL PALAEOENVIRONMENTAL IMPACTS IN NEW ZEALAND
… ash fall and toxic emissions outside the blast zone of a volcanic eruption. These effects are determined from palynological and geochemical changes following tephra fall at a range of sites across the North Island of New Zealand which were located at increasing distances from the main …
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Late Quaternary climate variability and terrestrial carbon cycling in tropical South America
… hydrologic trends at these two sites during the last glacial period suggest altered monsoon circulation patterns under glacial conditions, while changes in summer insolation appear to be an important control of precipitation at both sites during the Holocene. I next assess the relationship …
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Nocturnal Lepidoptera of Midland Raised Bogs
… in water-filled depressions left after the last glacial period. Due to centuries of damaging human activities, only 1% of the living, growing active raised bog habitat remains and this is rapidly being lost. Raised bogs are important reservoirs of biodiversity, hosting many uniquely adapted …
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Chronology and paleoenvironment of Peoria Silt deposition and Jules Geosol development along the Illinois Valley, Illinois, USA
… Geosol were previously not well understood. This last glacial paleosol developed in thick loess deposits (Peoria Silt) proximal to the Illinois River Valley around the time of the last glacial maximum. Two sites, New Cottonwood School and Thomas Quarry, which contain the Jules Geosol, were …
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Late Quaternary climate variability and terrestrial carbon cycling in tropical South America
… hydrologic trends at these two sites during the last glacial period suggest altered monsoon circulation patterns under glacial conditions, while changes in summer insolation appear to be an important control of precipitation at both sites during the Holocene. I next assess the relationship …
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Questions and clarity: insights from applying computational methods to paleoclimate archives
… facies in the tufa at Searles, grown during the Last Glacial Period, and those forming presently at Mono Lake. Next, the tracks of icebergs purged during Heinrich Events are simulated using the MIT General Circulation Model. This work, running multiple experiments exploring different aspects …
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Subglacial rhyolite volcanism at Torfajökull, Iceland
Subglacial rhyolite eruptions at Torfajökull, Iceland have produced a variety of volcanic edifices during the last glacial period (115-11 ka). These range from small-volume (<0.1 km<sup>3</sup>) volcanoes, such as Bláhnúkur and Dalakvíslfell, to larger volume (~1 km<sup>3</sup>) flat-topped tuyas …
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Questions and Clarity: Insights from Applying Computational Methods to Paleoclimate Archives
… facies in the tufa at Searles, grown during the Last Glacial Period, and those forming presently at Mono Lake. Next, the tracks of icebergs purged during Heinrich Events are simulated using the MIT General Circulation Model. This work, running multiple experiments exploring different aspects …
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Effects of Glaciation on Volcanism in Iceland
Volcanic eruption rates in Iceland during the last deglaciation increased 5--30 fold from the steady-state rates. This has been understood by the unloading of ice, which increases the decompression rates in the mantle, causing enhanced mantle melting rates. However, existing theoretical work cannot …
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Palaeoclimatic impacts on the phylogeography of an Afro-montane liverwort: Jamesoniella colorata (Lophoziaceae )
… probably taken place throughout the Quaternary glacial-interglacials cycles, , which are thought to have been influential in shaping modem patterns of diversity. In lV an attempt to assign approximate dates to the two expansion events inferred for J. colorata, an average chloroplast mutation …
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Sulfate in foraminiferal calcium carbonate : investigating a potential proxy for sea water carbonate ion concentration
… and benthic foraminifera from Holocene and last glacial period sediments were measured in an effort to use the established relationship of S/Ca and pH to calculate the ocean pH gradient between Holocene and glacial time. The results indicate the pH of global ocean deepwater was 0.10 to 0.15 …
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Reconstructing climate from the Dead Sea sediment record using high-resolution micro-facies analyses
… graded and slumped deposits including coarse clastic detritus. Core 5017-1 encompasses a succession of four main lithological units. Based on first radiocarbon and U-Th ages and correlation of these units to on-shore stratigraphic sections, the record comprises the last ca 220 ka, i.e. the …
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Late Quaternary palaeoenvironments and Middle-Late Stone Age habitat preferences in the Nakuru-Naivasha Basin, Kenya: phytolith-based evidence from the site of Prospect Farm
… may have existed here during the late Quaternary period. Such putative refugia are posited to have been centered around highland lake basins that could have buffered human populations, plant, and faunal communities from the most severe deteriorations of climate during the last glacial period. On a …
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