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 25 for “"Firn"”.
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Firn Pack Changes on White Glacier, Axel Heiberg Island, Nunavut
… processes and variability within the firn pack of Arctic glaciers are a significant source of uncertainty in estimating future glacier responses to climate warming. This study provides the first characterization of the firn pack of White Glacier, Axel Heiberg Island, Nunavut, and an …
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Firn stratigraphy and névé regime trends on the Juneau Icefield, Alaska, 1925-65
Thesis (M.S.)--Michigan State University. Dept. of Geology, 1965
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Advances in understanding melt-affected firn and ice cores from the polar regions
… proxies. The age scale development for a new firn core from Young Island exemplifies the challenges and potential of records impacted by melt. In this context, my PhD research contributes to a more comprehensive understanding and new avenues of studying melt-affected firn and ice cores by …
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Trace gases in Antarctic and Greenland firn and ice: a record of carbonyl sulphide and the isotopologues of chlorofluorocarbons
… (NEEM) and Antarctic (Fletcher Promontory) polar firn, with additional samples taken from an archive of Southern Hemispheric background air (Cape Grim, Tasmania). This study extends the novel approach to measuring trace gas isotope ratios in small air volumes (200 – 600 ml), using a …
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Amundsen Sea sea-ice variability, atmospheric circulation, and spatial variations in snow isotopic composition from new West Antarctic firn cores
… to West Antarctica in the past. I validate new firn-core sea-ice proxies over the satellite era; results indicate that firn-core glaciochemical records from this dynamic region may provide a proxy for reconstructing Amundsen Sea and Pine Island Bay polynya variability prior to the satellite era. …
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Amundsen Sea sea-ice variability, atmospheric circulation, and spatial variations in snow isotopic composition from new West Antarctic firn cores
… to West Antarctica in the past. I validate new firn-core sea-ice proxies over the satellite era; results indicate that firn-core glaciochemical records from this dynamic region may provide a proxy for reconstructing Amundsen Sea and Pine Island Bay polynya variability prior to the satellite era. …
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Study of atmospheric carbon monoxide and methane
… and Africa. We also measured d13C and dD on firn air samples from two Antarctic sites. From these measurements the atmospheric trends of d13C and dD of CH4 over the past fifty years have been reconstructed with the help of a firn air diffusion model. We find that parallel to increasing CH4 …
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Studies of Seismic Sources in Antarctica Using an Extensive Deployment of Broadband Seismographs
… that these events are sourced in the upper firn layers and can be used to determine firn thickness in East Antarctica by inverting group velocity dispersion for shear velocity.</p>
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Ice core methane and carbon monoxide as tracers of the terrestrial biosphere since the pre-industrial
… Instead, low-resolution measurements of firn air have often been used to bridge the gap between the end of ice core gas records and the start of direct atmospheric observations. Explanations for suspected periods of multidecadal trace gas variability across the 19th and 20th …
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Impact Analysis and Design Development for Air-Dropped Antarctic Seismo-Geodetic Ice Penetrator
… systems. Impact modeling of SGIP into glacial firn is detailed, with a focus on fast simulation run-times for design exploration. Designs of snow spikes and a rigid antenna mast are detailed, analyzed and tested. Results from a full-scale prototype hardware test in Juneau, Alaska are discussed.
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The Effects of Snowmelt Percolation on Stratified Pollen Records: A Cooler Study
… large amounts of pollen in the surface snow and firn, and dearth of pollen in the glacial ice core samples. The purpose of this study is to investigate if meltwater percolation can effectively transport pollen in a way that results in reduced pollen concentrations in deeper layers of the glacier. …
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Historical anthropogenic emissions of carbon monoxide, 1850 - 2000
… CO concentration trend measured in Greenland firn air.
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Analysis of the surface hydrology of the Greenland Ice Sheet using Sentinel-1 Synthetic Aperture Radar
… to its ability to pond to form features such as firn slush zones and supraglacial lakes. This study uses imagery from the recently launched Sentinel-1 Synthetic Aperture Radar sensors to investigate supraglacial lakes in southwest Greenland. This novel method can overcome some of the limitations …
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Radio Echo Studies of Glaciers
… free water, or solid ice within less dense firn. A v.h. f. radar system has been designed specifically to produce continuous profiles of ice thickness when used either on the surface of a glacier, or in an aircraft flying over it. The frequency dependence of the attenuation mechanisms …
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Surface reflectance characteristics of Langjökull, Iceland
… area, greatly underestimate the albedo in the firn zone and struggle to capture the spatial variability in the ablation zone. The implications of these characteristics for lower resolution data have consequently been outlined, with the extent of the differences between both the low resolution …
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The glacial geomorphology of part of the Western Grampians of Scotland, with especial reference to the limits of the Loch Lomond Advance
… valley and plateau glaciers indicate that firn lines rose from ca. 400m O.D. in the SW to +900m O.D. in the NE part of the study area. Trend surface analysis of corrie-floor altitudes, the spatial distribution of amounts of precipitation at the present time t and the equilibrium rim lines …
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Iodine in sea ice and the polar atmosphere.
… of CH3I and C2H5I were measured in the snow firn air, with a diurnal profile, suggesting the snow may be a source of these compounds. These measurements have implications for atmospheric mixing ratios of IO, measured from the ship and validated by satellite data, and new particle formation. …
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