Thesis (B.A.)--Haverford College, Dept. of English, 2007. / Includes bibliographical references.

In January-February 1971 five replicate 0.07 m² Van Veen grabs were obtained from each of 12 stations in Arthur Harbor and nine Van Veen grabs were obtained from two stations in nearby Bismark Strait. The 69 grab samples yielded 78,395 individuals which were separated into 282 taxa, including 108 species of annelids (54.5% of the individuals), 117 species of arthropods (30.3%), 35 species of molluscs (11.3%) and 22 species in other phyla (4.0%). The density of macrofauna (17,522 individuals/m²) found in Arthur Harbor was high compared to other reported areas. This high density was considered to be the result of high organic input from phytoplankton, phytobenthos and attached macroalgae, the efficient utilization of organic matter by macrobenthos and the slow growth rate of macrobenthic species as an indirect result of cold temperatures. Diversity values were moderately high with high species richness values and low evenness values. The high species richness values may be the consequence of seasonal constancy of temperature and salinity in Arthur Harbor, while low evenness values probably result from the physical stress of iceberg grounding coupled with high organic input. Six macrobenthic assemblages (site groups) and 11 species groups were found in the study area by classification analysis (Bray-Curtis dissimilarity, group-average sorting). Station groups were described by dominant species, density and diversity. Species groups were described by the dominance, fidelity, constancy, and percent abundance of constituent species restricted to site groups. The existence of discrete assemblages derived from the classification analysis was supported by direct ordination. Assemblages were interpreted to be areas of relative homogeneity which interrupt a general continuum of distribution of species with depth. The depth gradient probably represents several factors including increased constancy of temperature and salinity, lower organic input from attached macroalgae and phytobenthos, and a reduced incidence of iceberg grounding. Diversity, species richness, and evenness values increased with the depth gradient, while density values decreased with depth. The dominant species obtained in this study are widely distributed throughout the Antarctic, and 4% of the 162 taxa identified to species were also found at Terre Adelie, East Antarctica. Thus assemblages found in Arthur Harbor are probably circumpolar. In spite of the stability of temperature and salinity, Arthur Harbor macrobenthic assemblages were moderately stressed by glacial activity Icebergs, which often ground in Arthur Harbor, destroyed the benthos by crushing and churning the sediment. The disturbed area was first repopulated by motile, opportunistic species. These species fed on macroalgae which collected in the depression left by the iceberg. Scavengers and carnivores appeared later to feed on the grazers and macrofauna destroyed by iceberg grounding. Within a year the depression filled, and typical meiobenthic assemblages were re-established. Several years may be required before macrobenthic assemblages are re-established. Station 8, located near the glacial face had the lowest values of diversity, species richness, evenness, and density of any station in Arthur Harbor. These low values resulted from physical stress of glacial calving. Large pieces of ice calved from the glacial face and crushed the sediment by impact with the bottom. The waves created by impact of the calved ice with the water also disturbed the sediment creating an unstable sediment surface. / Graduation date: 1977

No description available.

Biosecurity is one of the main mechanisms used to protect and mitigate the introduction of non-indigenous species. Effective biosecurity requires a knowledge and understanding of pathways and vectors along which invasion can occur. This study contributes to our knowledge and understanding of possible biosecurity risk factors in the Antarctic by identifying potential vectors for invasive species in the pathway between New Zealand and the Antarctic. The Antarctic has important indigenous terrestrial and marine, plant and animal species, all of which contribute to the food chain in Antarctica and the Southern Ocean. This study seeks to contribute some baseline data about pathways and vectors between the two regions and the implications for the biosecurity of both. An assessment of some of the risks associated with human activities within the Antarctic region, including the traffic of people and goods to and from the area, are the focus of this thesis. Current biosecurity practices with regard to personnel, shipping containers, and fresh produce are examined and where appropriate, recommendations to alleviate any detected risks are made. The results of the research indicate a significant volume of seed and plant material being unintentionally transported to Antarctica. The most striking finding was the presence of seeds in new clothes, which have previously been assumed not to be vectors. The presence of seeds in soil samples in Antarctica suggests that seeds have probably already been transported to Antarctica. Presently the climate in Scott Base seems to prevent non-indigenous species from becoming established. However, with the increases in temperature being experienced in Antarctica, this may not always be the case, therefore greater attention to biosecurity legislation and its implementation is required.

No description available.

Within the Ruker Province of East Antarctica, there is evidence for several key geological events that have occurred coincidently with periods of dynamic earth evolution. A detailed evaluation of the tectonic history of the region is therefore required. This research focuses on the tectonic development of the Ruker Province. The main aspects of this research can be summarised as follows: (1) an evaluation of the gross crustal architecture of the region through the development of a new stratigraphic and structural framework; (2) new U-Th-Pb (LA-ICPMS) age data from detrital zircon grains extracted from thick metasedimentary units that comprise a major component of the Ruker Province; (3) new 40Ar/39Ar data from metamorphic minerals to determine the cooling history of the province; (4) mineral equilibria modelling of metamorphic mineral assemblages to constrain pressure-temperature (P-T) conditions during key orogenic events; (5) a kinematic analysis of brittle/ductile deformation features. Ideas developed from these new data provide inferences on the assembly and dispersion of the late Proterozoic super-continents Rodinia (c. 1000 Ma) and Gondwana (c. 500 Ma).

Thesis (Ph. D.)--Mawson Institute for Antartic Research, University of Adelaide, 1987. / Addendum inserted. Includes bibliographical references.

Thesis (M. Sc.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (p. 70-75). Also available via the World Wide Web.

Thesis (Ph. D.)--Montana State University--Bozeman, 2005. / Typescript. Chairperson, Graduate Committee: Edward E. Adams. Includes bibliographical references (leaves 129-136).

Originally presented as the author's thesis, Universidad de Chile, Santiago, 1944. / Includes bibliographical references (p. [203]-209).