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 49 for “"ice core"”.
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Time-series trends of trace elements in an ice core from Antarctica
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1995.
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New ice core records from West Antarctica and their spatial context: from 1000 to 100,000 years
The West Antarctic Ice Sheet (WAIS) is vulnerable to warming as a result of anthropogenic climate change, with the potential to contribute several metres to global sea level rise over the coming centuries. The Thwaites and Pine Island glaciers are already undergoing acceleration due to climate …
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Ice core methane and carbon monoxide as tracers of the terrestrial biosphere since the pre-industrial
Ice core trace gas records have defined our understanding of carbon cycle feedbacks over the last 800,000 years. Yet, due to the slow process by which snow transforms into ice, few Antarctic ice core records have been able to capture highly resolved atmospheric information over the most recent …
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Concentration and Size Distribution of Microparticles in the NGRIP Ice Core (Central Greenland) during the Last Glacial Period
… were investigated in the deep North Greenland Ice Core Project (NGRIP) ice core. The measurements were accomplished using a novel, optical detector which is based on laser light attenuation by individual particles. The device works on a flow-through basis, and together with sample preparation …
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Ice-core records of the chemical quality of atmospheric deposition and climate from mid-latitude glaciers, Wind River Range, Wyoming
Includes bibliographical references (pages 166-174).
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Black Carbon Measurements of Snow and Ice Using the Single Particle Soot Photometer: Method Development and an AD 1852-1999 Record of Atmospheric Black Carbon from a Mount Logan Ice Core
… and by reducing the albedo of snow and ice when deposited. Measuring BC in snow and ice is important for estimating albedo reduction and developing historical records of BC concentration. Experiments were conducted to further develop a method for measuring BC in snow and ice using the …
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‘Organics in ice’: Novel organic compounds in ice cores for use in palaeoclimate reconstruction
The majority of current ice core studies focus on analysing the inorganic component of atmospheric aerosol, trapped and preserved in the ice as a record of past atmosphere. However, this does not fully represent the make-up of atmospheric aerosol, which can be up to 50% organic. This thesis aims to …
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Analysis of microbes in Greenland ice cores from periods of high and low atmospheric carbon dioxide levels
Glacial ice entraps microbial cells and nucleic acids that have been deposited from the atmosphere by precipitation or on dust particles carried by the wind. The ice is deposited in sequential layers representing distinct past periods of time. Metagenomics and metatranscriptomics offer means to …
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Greenlandic ice archives of North Atlantic Common Era climate
… climate variability from the Greenlandic ice core archive. First, I investigate the climatic fidelity of ice core glaciochemical climate proxies at the microphysical-scale.
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150 Years of Light Absorbing Impurity Deposition on South Cascade Glacier, Washington State USA
… energy absorption and melt. We used a 158 m long ice core collected from the South Cascade Glacier in the North Cascades of Washington State to reconstruct 20th century BC deposition. The ice core was processed into 1,989 segments averaging 7.75 cm and BC was measured using a Single Particle Soot …
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Uncovering the Potential of Utilising Terrestrial Biogenic Markers in Ice Cores as Proxies to Past Environmental Conditions
Ice cores provide an un-matched high-resolution archive into paleoclimate reconstruction that other environmental archives (e.g. coral, sediment cores, and tree rings) do not. Limited research has focussed on terrestrial organic matter within ice cores. However, given the known relationships …
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Assessment of Black Carbon in Snow and Ice from the Tibetan Plateau and Pacific Northwest
<p>An ice core from Mt. Geladandong, Tibetan Plateau, spanning 1853-1983, and snow samples collected over two winters from the Cascade Mountains were analyzed for concentrations of black carbon (BC) using a Single Particle Soot Photometer (SP2). From the ice core, the high-resolution BC record …
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Advances in understanding melt-affected firn and ice cores from the polar regions
Rising temperatures are an increasing issue for ice core science around the world, even in the polar regions where near-surface melt and rain-on-snow events are occurring more frequently, more extensively, and adversely affect the preservation of numerous ice-core climate proxies. The age scale …
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Advanced Methods for the Analysis of Radar Sounder Data Acquired at the Ice Sheets
… complete collection of information about the ice sheets and glaciated areas is contained in the data (radargrams) acquired by Radar Sounder (RS) instruments. The need to better understand the structure of the ice sheets and the availability of enourmous quantities of radargrams call for the …
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Development of a multi-tier system for the analysis of ice crystallography of Antarctic shelf ice
This research delves into the complex ice dynamics of the under-studied Antarctic shelf ice, aiming to establish a comprehensive, multilevel approach for analyzing ice layer crystallography in these regions, with a specific focus on c-axis orientations and grain sizes. This approach encompasses the …
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Using Radar and Seismic Methods for the Determination of Ice Column Properties and Basal Conditions at Jakobshavn Isbræ and the NEEM Drill Site
… crystal orientation fabrics (COF) within the ice column can have a strong influence on the flow behavior of an ice sheet or glacier. Typically, COF information comes from ice cores. Observations of anisotropic seismic wave propagation and backscatter variation as a function of antenna …
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Folding of stratigraphic layers in ice domes
… of recumbent folds in stratigraphic layers of ice sheets such as those in Greenland and Antarctica. The initial disturbances in the stratigraphy have their roots in transient dynamic processes and local rheological inhomogeneities, but the kinematics of even a simple ice flow model can deform …
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Investigating Tropospheric Hydrogen Peroxide Trends from 1950-2014
… term data of H₂O₂ primarily available through ice core records. Given the lack of observational data, much of our knowledge on the history of tropospheric oxidants relies on modeling studies. We quantify the global H₂O₂ burden and trends between 1950 and 2014 from the Community Earth System …
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Greenlandic ice archives of North Atlantic Common Era climate
… climate variability from the Greenlandic ice core archive. First, I investigate the climatic fidelity of ice core glaciochemical climate proxies at the microphysical-scale. I show that several soluble chemical species – key among them methanesulfonic acid (MSA) – undergo rapid vertical …
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Innovative water tracers and water isotopes enhance Antarctic research with climate models
… impacts from natural variability, Antarctic ice cores preserve valuable information about past climate evolution. As the interpretation of ice core records is confounded by many influencing factors, climate models are instrumental in elucidating relevant processes. Here I aim to leverage …
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