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Intergranular Water and Permeability of the Lake Vostok Accretion Ice, Eastern Antarctica: Author: Jepsen, Steven Michael; Date: 2005-12-15; Program: Engineering; Abstract: The relative importance of nonhydrostatic stress and lattice-rejected impurities on the phase equilibrium of intergranular liquid water in the Vostok accretion ice, Eastern Antarctica, was examined in this study. In addition, experiments were conducted to examine the influence of intergranular water in ice on the permeability of a Light Non-Aqueous Phase Liquid (LNAPL) hydrocarbon. Sub-grain scale stresses in the Vostok accretion ice were simulated with anisotropic elastic and elastocreep finite element (FE) models and compared to X-ray dislocation topographs. The phase equilibrium conditions ...; Download File | View full details

Recruitment Probabilities and Reproductive Costs for Weddell Seals in Erebus Bay, Antarctica: Author: Hadley, Gillian Louise; Date: 2006-05-15; Program: Biological Sciences; Abstract: The study of life history traits such as age at first reproduction and the evaluation of recruitment probabilities and reproductive costs allow insight regarding the diverse factors and mechanisms shaping reproductive strategies. We investigated these mechanisms using a 26-year mark-resight dataset for Weddell seals (Leptonychotes weddellii) in Erebus Bay, Antarctica. Mean age at first reproduction was 7.62 years of age (SD=1.71), but varied from four to 14 suggesting the presence of important heterogeneity in quality among females. Survival rate was maximized for offspring of age-14 mothers (...; Download File | View full details

Microbial Ecology of an Antarctic Subglacial Environment: Author: Mikucki, Jill Ann; Date: 2005-12-15; Program: Land Resources and Environmental Sciences; Abstract: The research presented in this dissertation focused on the microbial ecology of the subglacial discharge from the Taylor Glacier in the McMurdo Dry Valleys, Antarctica. The major objectives of my research were to 1) define the biogeochemistry of the subglacial outflow 2) describe the microbial diversity of the subglacial outflow and 3) examine the impact of subglacial outflow on the geochemistry and biology of the west lobe of Lake Bonney, a lake that abuts the glacier. The subglacial outflow from the Taylor Glacier is known as Blood Falls owing to a visible accumulation of iron-oxides at the ...; Download File | View full details

Diversity, Productivity, and Physiology of Microorganisms in the Stream-Moat-Lake Transition of Lake Bonney, Antarctica: Author: Moore, Joel Grant; Date: 2007-05-15; Program: Land Resources and Environmental Sciences; Abstract: Air temperatures exceeding 0°C in Taylor Valley, Antarctica 17-25 degree days each summer and constant solar irradiance melt glacial and lake ice to from liquid water moats at the edges of permanently ice-covered lakes. Moats are fed by glacial streams and interact with comparatively large volumes of ice-covered lake water. This study investigated stream influence on moat chemistry and microbial biomass, productivity and diversity in the moat of East Lake Bonney (ELB) and compared the moat to the ice-covered portion of ELB. Stream inflow was a source of dissolved ions, inorganic car...; Download File | View full details

Mass dynamics of Weddell Seals in Erebus Bay, Antartica: Author: Proffitt, Kelly Michelle; Date: 2008-05-15; Program: Fish and Wildlife Biology; Abstract: An individual's body mass is an important life history trait that may vary with environmental conditions and be related to reproductive performance. In this dissertation, we used a 35-year dataset to investigate variations in body mass of Weddell seals (Leptonychotes weddellii) in Erebus Bay, Antarctica with goals of linking environmental conditions, body mass, and reproductive performance. We predicted that variations in environmental conditions and maternal traits would correlate with variations in maternal body mass at parturition, and that variations in maternal body mass may be linked wi...; Download File | View full details