Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). One map in pocket. Includes bibliographical references (leaves 131-145). Also available via the World Wide Web.

Thesis (M.Sc.)-- Memorial University of Newfoundland, 1992. / Typescript. Bibliography: leaves 179-194. Also available online.

Thesis (Ph. D.)--University of Washington, 1996. / Accompanying maps: Plate 1: Quaternary geologic map of the Hoh, Queets, and lower Clearwater valley, Washington. Plate 2: Stratigraphic cross-section, Hoh River to Raft River. Vita. Includes bibliographical references (leaves [131]-139).

The Younger Dryas was the last period during which glaciers shaped large parts of the Scottish landscape. Reconstructing the palaeoclimate and glacial processes that operated during this time is crucial for the understanding of past atmosphere-cryosphere interactions and predicting future climate change. This thesis presents results from geomorphological and geological mapping in the NW Highlands of Scotland that have resulted in the reconstruction of a Younger Dryas ice cap. Reconstruction of equilibrium-line altitudes and palaeo-precipitation values suggest that the Scottish west coast was wetter than at present. Detailed sedimentological analyses of "hummocky moraines" allow the modes of moraine formation to be reconstructed in great detail and existing models to be tested. "Hummocky moraines" largely represent terrestrial ice-contact fans consisting of supraglacial debris flows and intercalated glaciofluvial units indicating an ice-marginal mode of formation. Different stages of deformation in these fans indicate highly dynamic glaciers that oscillated during retreat, partly or completely overriding previously formed landforms during readvances. Clast shape analyses reveal that debris was mostly subglacially derived and transported. The evidence is incompatible with a morphological model according to which the moraines could be formed by englacial thrusting. Comparison with modem glacial landsystems indicates the following similarities with Scottish Younger Dryas glaciers. Low winter temperatures are similar to those on Svalbard, the marginal response of Younger Dryas glaciers to temperate environments and the modes of deposition to less responsive debris-covered glaciers. High precipitation along the Scottish west coast probably suppressed continuous permafrost development and caused high mass turnover and very dynamic, dominantly temperate Younger Dryas glaciers. Only a narrow zone around the margins appears to have been frozen to the ground, aiding elevation of basal debris and rapid deposition near the snout. The specific climatic and glaciological conditions during the Younger Dryas appear not to have a single modem analogue.

By only considering records of climate and glaciers over the period that humans have been monitoring them, one might think that climate normally changes quite rapidly, and that glaciers have always been small. But in the not-so-distant past, an ice sheet covered the Southern Andes, flowing across the southern tip of the continent, and in some places, even terminating into the Atlantic Ocean. Glaciers rewrite the surfaces they inhabit, leaving behind indicators of their past behavior. By studying the landforms they create, we can reconstruct climates of the past. Here I present unique and novel glacier-climate reconstructions over southern and central Patagonia using a state-of-the-art dating approach tied to high resolution spatial mapping and glaciological modeling. The main goal of this thesis is to constrain the precise timing and character of the past advances of three glaciers in Patagonia. To this end, I present new precise 10Be surface exposure datasets from two paleo outlet glacier lobes (at 45°S and 53°S), totaling 71 new moraine boulder ages. In these two valleys, I am able to reconstruct the last three major glaciations (MIS 6, 4, 2), as well as provide a constraint for the last two terminations (T1, T2). At a third site, I create a novel dataset to reconstruct the behavior of the Calluqueo glacier (48°S) from ~7,000 years ago to the present. All three sites are eastwards of the main Andes mountain range, spanning from southernmost Patagonia (53°S) to central Patagonia (45°S). To achieve my thesis objectives, I employed recent improvements in the 10Be exposure dating method, and tied the geochronological studies to new, high resolution maps of the glacial geomorphology created by the former glaciers and associated processes. We find in central Patagonia, the Ñirehuao glacier lobe was most extensive potentially during Marine Isotope Stage (MIS) 8, but certainly prior to MIS 6, followed by a major advance during MIS 6. This study presents one of the first directly dated records of a MIS 6 glacier expansion in Patagonia at 153±5.1 ka, where the glacier may have been in retreat at 137±4.2 ka. During the last glacial cycle, the glacier was most extensive during the middle of MIS 2, at 23.6±0.9 ka. The southernmost section of the Ice Sheet, at Estrecho de Magallanes, was more extensive during Marine Isotope Stage 4 (MIS 4) than during MIS 2, representing the first direct dating of the MIS 4 glacier culmination in South America. Similar to the MIS 2 glacial maximum, within MIS 4 there were multiple advances that we date (6 samples) to between 67.5±2.1 and 62.1±2.0 ka. Inboard of the MIS 4 moraine complex, we date a sequence of geomorphically distinct MIS 2 moraines that represent separate major periods of glacial stability. The MIS 2 maximum extent occurred by 27.4±0.8 ka and was followed by at least four more full glacial culminations over a hundred miles beyond the Andes mountains. About 18 km inboard of the main MIS 2 landforms, the sequence is followed by smaller-scale recessional moraine crests that we date to 18.0±0.8 ka, indicating the glacier was in net retreat at this time. In order to estimate the climate conditions necessary to drive the glacier advances that we date and map, we apply the University of Maine Ice Sheet Model to the Estrecho de Magallanes and Ñirehuao records. Tentative results suggest that the Magallanes lobe may have reached mapped inner and outer MIS 2 moraines with a climate that had approximately 4.5°C and 5.5°C cooler summers, respectively, assuming about 25% less annual precipitation relative to modern conditions. A new record at Calluqueo, in central Patagonia, allows us to reconstruct Holocene (interglacial) glacier changes. Using 33 new 10Be ages with unprecedented precision, geomorphic mapping and historical imagery, we find that the Calluqueo glacier sat at its mid-Holocene maximum extent from ~6,900 until ~6,700 years before the present. Major moraine forming advances subsequently culminated at least seven more times, averaging every 500±31 years, between 5,620±203 and 3,120±106 years ago. A hiatus in moraine formation occurred from 3,120±106 until 1,160±50 years ago (860 CE). Major retreat occurred between 1600-1800 CE, followed by stability from 1800-1940 CE, and pronounced ongoing retreat since after 1940 CE. For the Holocene period, this record represents one of the first precise, directly-dated glacier histories from central Patagonia, and one of the few available for all of Patagonia. The timing of advances of the Calluqueo glacier has little in common with the glacial histories from the Northern Hemisphere, suggesting an inter-hemispheric asynchronicity. All together, we reconstruct the timing of glacial maxima at three sites in terrestrial Patagonia from 53°S to 45°S, with unprecedented precision, from pre-MIS 6 to the present day.

No description available.

Thesis (Ph. D.)--University of Canterbury, 2006. / Typescript (photocopy). "August 2006." Includes bibliographical references (leaves 289-292). Also available via the World Wide Web.

No description available.

No description available.

The prehistory of the Yukon-Kuskokwim Delta is poorly understood and the region today is home to the Yupiit, whose traditional lifeways revolve around animals. However, the fur trade and Christianity limit the use of ethnographic data to fully understand pre-contact human-animal relationships and subsistence in particular. The discovery of the prehistoric site of Nunalleq (15th-17th c. AD), therefore provides a unique opportunity to address this issue and opens a window to explore human responses to the Little Ice Age. In this research, a zooarchaeological analysis was undertaken to investigate animal exploitation at Nunallleq, potential changes in subsistence strategies and the nature of the faunal assemblage. Results suggest that people at Nunalleq focused primarily on salmon, marine mammals and caribou with migratory waterfowl possibly playing an important role at specific times of the year. This tripartite subsistence strategy appears to have provided the inhabitants of the site with the flexibility and necessary coping mechanisms to face potential environmental-related stress during the Little Ice Age by relying more on other resources, such as seals and caribou, when experiencing a reduced availability of salmon. The choice to settle at Nunalleq may have been strategic in order to have good access to multiple key resources simultaneously and it is suggested that perhaps the possible decline in salmon may be related to prehistoric warfare in the region. It is also highlighted that bone working and dog gnawing contributed to the formation the Nunalleq faunal assemblage. This raises further questions as to the nature and meaning of arctic and subarctic archaeofaunas and highlights the importance of multiple lines of evidence to document past human-animal relationships. This study better informs our understanding of Nunalleq forming a baseline for further subsistence studies in the Yukon-Kuskokwim Delta.