<p>The Eastern Antarctic Dry Valley region is a polar desert, where conditions of extreme aridity, high temperature fluctuations and high irradiation levels make it one of the most extreme environments on earth. Despite the harsh environment, the soils in this region yield a wide range of bacterial and eukaryotic phylotypes in greater abundance than previously believed. In the Dry Valleys, highly localized niche communities colonise the underside of translucent quartz rocks and present macroscopic growth.</p>

Polybrominated diphenyl ethers (PBDEs) are anthropogenic chemicals whose environmental behavior is similar to the well-known polychlorinated biphenyls (PCBs). Few studies have quantified the amount and distribution of PBDEs in the southern hemisphere and Antarctica. The analyses reported in this dissertation document the levels of PBDEs in lichens, mosses and seabird eggs collected at King George Island, Antarctic Peninsula. The analyses were carried out using Gas Chromatography/Electron Impact-Mass Spectrometry (GC/EI-MS). Employing the ion stacking technique lowered detection limits and ensured instrument selectivity and sensitivity to the compounds of interest. Lichens and mosses absorb PBDEs directly from the atmosphere and their contamination indicates that long-range transport is the primary source of these chemicals to King George Island. The congener patterns of PBDEs in plants indicate that commercial mixtures of Penta-BDE and Octa-BDE have reached Antarctica. Differences in the levels of PBDEs observed in lichens and mosses are probably due to factors that govern the uptake of PBDEs from the atmosphere. Contamination in lichens showed a positive correlation with local precipitation. Conversely, absorption of PBDEs in mosses appears to be controlled by other plant-specific factors. Marine phytoplankton-derived aerosols are hypothesized to play an important role in the atmospheric transport of PBDEs to the Antarctic environment. PBDEs in south polar skua eggs revealed much higher concentration than in penguin eggs. This is likely associated with the northward migration of these seabirds during the non-breeding season. While penguins reside year-round in Antarctica, south polar skuas migrate northward and can be seen in boreal oceans during the austral winter. Distribution of PBDEs in penguin eggs matches the pattern found in local vegetation suggesting a common source for the chemicals. In contrast, the congener pattern of south polar skuas suggests that birds breeding at King George Island are wintering in the northwestern Pacific Ocean. A potential metabolism of PBDEs in penguin eggs during the incubation period seems to be limited. Most congeners were unaltered from source material in the eggs of chinstrap and gentoo penguins. Low levels of PBDEs, short incubation periods and energy constraints may explain these observations.

This work explores a fascinating and disturbing literary trope found in select German Expressionist prose in the years 1910-1920. Key Expressionist-era authors, including Georg Heym, Robert Musil, Egmont Colerus and Franz Kafka employed Antarctic and ice metaphors in their poetry and prose to exemplify inner feelings of displacement resulting from modernity. Expressionist discontent, as well as the “Heroic Age of Antarctic Exploration” that occurred from 1895 to 1922, led to the creation of polar dystopias in some literature. These dystopias explored abstract interpretations of the South Pole, not as a place of excitement and adventure, but rather as a journey into philosophical inner ice in the era of Modernism. Heym, Musil and Colerus did not invent the disturbing Antarctic allegory, but rather returned to an established literary tradition in a time of polar “pulp” fiction.This thesis first examines the South Pole as a place of emptying, shown in Georg Heym's 1911 fragment “Das Tagebuch Shakletons” (“Shakleton's Diaries”). In other works, such as Heym's 1911 novella “Die Südpolfahrer” (“Travelers to the South Pole”), the South Pole is portrayed as a blank slate. Two Austrian works show the idea of the South Pole as a refuge: Robert Musil’s 1911 Das Land über den Südpol (“The Land over the South Pole”) and Egmont Colerus’ 1915 novel Antarktis. These works exemplify and interpret the modern soul’s tepid “temperature,” something sharply criticized by Expressionists. These authors and poets longed to see an improved world and expressed discontent by portraying imperialist “heroes” of their time as mere specks lost in the sea of modernity. In the literature of Heym, Musil, Colerus and Kafka, a bleak Antarctic world mirrors the authors’ views on their “dying” society and the European “symptom” that resulted in suffocating mediocrity. Self-fulfillment becomes a static or moving point on the horizon that will never be realized by either the explorer or the freezing bourgeois soul.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 16, 2010). Includes bibliographical references. Also issued in print.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 174-184).

This thesis describes the results of new analysis of gravity studies over West Antarctica. Set on the Siple Coast, an airborne geophysical survey was flown between 1994 and 1997 that covered the trunk of Bindschadler Ice Stream and the up-stream areas, including Whitmore Accommodation Zone and Byrd Subglacial Basin. The new gravity reduction methodology removed vertical and horizontal accelerations, the Eötvös effect, and the theoretical gravity; unlike previous analyses, this reduction did not level individual lines, preserving the high frequency data and avoiding introduction of new errors. This reduction provided the free-air gravity disturbance over the area, which was then leveled and registered by the more regional extensive GOCE satellite gravity. The processing and reduction of the data improved the high frequency signal over previous work on the data, giving better definition of small scale, short wavelength features, which works well with satellite gravity data that emphasizes the large scale, long wavelength features. The leveled free-air gravity was then processed with a FORTRAN 90 program that calculates the Bouguer disturbance based on the free-air gravity and the topography. The topography was gathered concurrently with the gravity with ice penetrating radar during the airborne survey. The Bouguer disturbances provide a crustal model of the area. The final Bouguer disturbance was also corrected for the ice above sea level, which was calculated with a simple Bouguer slab correction. Finally, a power spectrum analysis was run on a profile in the Bouguer gravity disturbance in order to complete a spectral analysis. The spectral analysis provides crustal density boundaries for a density anomaly near the surface, a mid-crustal anomaly, and the Moho boundary. The improved the high frequency content of the data allows spectral analysis down to 4 km. The differing crustal thickness from spectral analysis also shows the character and extent of the West Antarctic Rift System, the northern flank of which extends out from Marie Byrd Land and into the survey area. Bindschadler Ice Stream is located on the WARS rift floor and MacAyeal Ice Stream sits on the rift flank. / text

<p>The Eastern Antarctic Dry Valley region is a polar desert, where conditions of extreme aridity, high temperature fluctuations and high irradiation levels make it one of the most extreme environments on earth. Despite the harsh environment, the soils in this region yield a wide range of bacterial and eukaryotic phylotypes in greater abundance than previously believed. In the Dry Valleys, highly localized niche communities colonise the underside of translucent quartz rocks and present macroscopic growth.</p>

The Devonian Taylor Group (the lower Beacon Supergroup), in the Taylor and Wright Valleys, southern Victoria Land (SVL), Antarctica, is separated from basement by a regional nonconformity, the Kukri Erosion Surface. Thereafter the Taylor Group sediments, observed in this thesis, are affected by two localized unconformities; the Windy Gully Erosion Surface, separating the Terra Cotta Siltstone Formation (TCzst) and older units from the younger overlying New Mountain Sandstone; and the Heimdall Erosion Surface (HES), separating the New Mountain Sandstone Formation (NMSst) and older units from the overlying Altar Mountain Formation. The depositional environments of the Windy Gully Sandstone, New Mountain Sandstone and Altar Mountain Formations have long been under debate. The Kukri Erosion Surface (KES) truncates the crystalline basement and separates the basement rock from the overlying Beacon Supergroup. Interpretation of the erosion surface characteristics and the directly overlying basal conglomerate lithofacies (WG-BCL) suggest a high relief rocky shore platform environment during a sustained and significant relative sea level fall. The environment has been suggested to be similar to what is currently seen on the West Coast, New Zealand today. The Windy Gully Sandstone Formation directly overlies the KES and consists of a basal conglomerate (WG-BCL) followed by moderately to well sorted tabular and trough cross bedded felds- to subfeldsarenites. At one location an interbedded siltstone and cross bedded sandstone lithofacies was observed and interpreted as a tidal flat. Overall interpretation of the WGSst suggests continued progradation from a rocky shore platform (WG-BCL) to a series low angle beach, to shallow marine, and back to low angle beach environments. This occurred during a relative sea level rise. Shallowing of the water column produced a gradational relationship with the Terra Cotta Siltstone Formation (TCzst).. The fine to very fine sandy mottled, well laminated siltstones moving to very fine fissile dark siltstones suggest a progression from sandy estuarine to a mud flat environment. The Terra Cotta Siltsone is truncated by the Windy Gully Erosion Surface The Windy Gully Erosion Surface is observed in the Handsley Valley by the presence of TCzst rip-up clasts in the directly overlying New Mountain Sandstone Formation. Elsewhere the horizon is either very sharp or has desiccation cracks present suggesting a cessation of deposition and subaerial exposure respectively. This suggests a small relative fall in sea level with only localized erosion. The New Mountain Sandstone Formation (NMSst) predominantly consists of a series of low angle tabular and higher angle trough cross beds. It has a subfeldsarenite base that progressively becomes a pure quartz arenites. Interpretation suggests an initial beach environment with rejuvenated sediments moving to quartzose shallow marine and back to beach environments. This represents a relative sea level rise with continued progradation The NMSst is truncated in the north by the HES forming a characteristic saw tooth pattern in the cross bedded sandstones; elsewhere the HES is represented by a feldspathic influx moving into the Altar Mountain Formation. The HES was formed due to a significant relative sea level fall leading to exposure and erosion of lithified NMSst cross beds in the north but continuation of deposition in the south. The Altar Mountain Formation consists of tabular and trough cross bedded subfields- to feldsarenites. The Odin Arkose Member directly overlying the HES is a granule to cobble conglomerate in the north where the HES is erosional and very coarse sand to granule feldsarenite in the south where the HES is conformable. This has been interpreted as a pebbly shore platform to coarse sandy to granular beach environment. The following Altar Mountain Formation is interpreted as a continuation of medium to coarse sandy beach environments with influxes of coarser sediments and possibly moving into shallow marine in places. Sequence stratigraphy identifies three stratigraphic sequences: S1, the Windy Gully Sandstone and Terra Cotta Siltstone Formations; S2, the New Mountain Sandstone Formation; and S3, the Altar Mountain Formation. The first two sequences (S1&S2) show a clear progression through transgression to a high stand systems tract through regression to a low stand systems tract. The Altar Mountain Formation follows a very similar trend but due to the lack of time and data the above measures have been speculated. Zircon age dating suggests the source of the sediments in the area come from the Neoproterozic Skelton Group and the DV2a Granite Harbour Intrusives, both directly underlying the sandstones but are exposed elsewhere in SVL. Laminated sandstone clasts within the New Mountain Basal Conglomerate Lithofacies (NM-BCL) are suggested to be sourced from recycled sediments directly below. Other exotic clasts are also observed in the lithofacies are of unknown origin.

In order to understand and predict the geochemical conditions in Antarctic meltwater ponds during winter, the geochemical extremes in Bratina Island meltwater ponds over a seasonal cycle were determined and compositional variation related to key physical, chemical and biological processes. A high resolution record of vertical temperature gradients in Skua Pond during freezing, winter and thaw, highlighted a significant seasonal temperature variation (10.3˚C to -41.8˚C) driven by air temperatures and the release of latent heat of fusion. A conceptual model of freeze-thaw involved heterogeneous melting, and explained how the presence of an ice plug near the base of the pond supports the strong chemical stratification observed, which can persist throughout summer. The geochemistry of Bratina Island meltwater ponds was shown to be catchment specific with correlation between geochemical parameters within ponds, but not between ponds. Basal brines that develop during freezing were nearer in composition to the brines preserved during summer, than to those present immediately post-melting. This is due to mineral precipitation during winter removing selected dissolved ions. Therefore winter brine predictions should be based on mid-late summer conditions, and allow for existing geochemical stratification. Nutrient concentrations were vertically stratified, by the same physical processes controlling major ion concentrations. However, the relatively low nutrient concentrations meant that biological processes exerted little influence over winter brine geochemistry. FREZCHEM62 modeled winter brine compositions were consistent with those of brines present during progressive freezing. Predicted mineral precipitation was also consistent with the presence of halite (NaCl), mirabilite (Na₂SO₄.10H₂O), thenardite (Na₂SO₄), magnesite (MgCO₃), gypsum (CaSO₄), sodium carbonate (NaCO₃) and calcite (CaCO₃) in pond sediments. FREZCHEM62 can therefore be used with confidence to predict winter conditions, as long as a reliable initial bulk pond water composition is calculated, and limitations, such as the over-prediction of carbonate mineral formation, are borne in mind.

This research is an integrated geological and geomorphological study into the Denton Hills area. The study area is part of the foothills to the Transantarctic Mountains, which divides East and West Antarctica, allowing an opportunity to investigate glacial events from both sides. As the study area is ice-free, it has allows good examination of the bedrock geology and has preserved geomorphological features allowing them to be examined and sampled. Comprehensive geological map and geomorphological maps have been produced, extending the knowledge into the spatial distribution of units and features. Both the geological and geomorphological maps reveal a complex history of evolution. The original geological units have been subjected to deformation and intrusion of large plutons. The geomorphological mapping shows ice has flowed in alternate direction through the valleys, and the valleys have had long periods where they have been occupied by large proglacial lakes. As the Antarctic ice sheets expanded they flowed into the valleys either from the west, the Royal Society Range draining the East Antarctic Ice Sheet or from the east, McMurdo Sound. Ice would flow from McMurdo Sound when the West Antarctic Ice Sheet expanded causing the grounding line of the ice sheet to move north through the Ross Sea. Surface exposure dating completed during the study has correlated the timing of glacial events to global cycles. The dating confirmed the presence of the large proglacial lake during the Last Glacial Maximum in the Miers Valley, which drained about 14 ka. The Garwood Glacier has also been directly linked to the Last Glacial Maximum with a moraine forming about 22 ka. The dating has also shown that during the Last Glacial Maximum there was little fluctuation in the size of glaciers draining the East Antarctic Ice Sheet, with features being date to the onset of the Last Glacial Maximum.