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Process-Morphology Interaction on Arctic Debris Slopes, S. W. Devon Island, CanadaBones, John George January 1971 (has links)
The study assesses process-morphology relationships on 27 debris slopes of an Arctic periglacial environment. A systematic sampling procedure is followed to obtain profile angle and debris size, shape and orientation for each slope. A rigorous test design to analyze size and shape variation has high statistical power and yields reliable results. Vector analysis is employed in the study of debris orientations, while non-parametric tests are performed on geometric parameters. Supplementary studies are made on rockfall accumulation and subsurface meltwater flow. Responses of slope geometry and debris characteristics to three major process groups are independently analyzed and compared in four selected localities, and the nature and effects of each process in the study area are presented. A discussion of interactions between the processes, geometry and debris concludes with a relative assessment of each process. / Thesis / Master of Science (MS)
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Identifying Iceberg Production Processes, Drift Patterns, and Coexistence with Ships in the Eastern Canadian ArcticDalton, Abigail 30 August 2023 (has links)
Tidewater glaciers drain a significant proportion of the Greenland Ice Sheet and ice masses of the Canadian Arctic and provide the primary source of icebergs in Canadian waters. However, there remains uncertainty surrounding the processes controlling ice discharge from Canadian Arctic glaciers, the drift paths of icebergs in Canadian waters, and the proximity of icebergs to shipping in the region. This thesis quantifies the processes controlling glacier dynamics from four primary glacier basins on the Prince of Wales (POW) Icefield and using a multi-year dataset of iceberg drift tracks, identifies drift patterns and proximity to ships throughout the eastern Canadian Arctic.
On the POW Icefield between 2009 and 2019, Cadogan and Ekblaw glaciers underwent multiyear acceleration and deceleration limited to their lower parts, consistent with characteristics of "pulse-type" glaciers. Trinity and Wykeham glaciers underwent repeating multiyear periods of velocity acceleration between 2009 and 2019 which coincided with significant thinning at their termini. As of 2017, Trinity and Wykeham were each within ~10 m of flotation over their lowermost 4 km. These findings suggest that Trinity and Wykeham glaciers have transitioned to a flow type dominated by dynamic thinning, which is strongly influenced by subglacial topography and may be susceptible to instability of the glacier front and large-scale collapse. Given that both glaciers are grounded below sea level for ~40 km up-glacier from their termini, this process could lead to significant increases in acceleration, retreat, and solid ice discharge.
Using a multi-year dataset (2011-2019) of in-situ iceberg drift locations, it was found that icebergs consistently drifted southeast along the east coast of Baffin Island, controlled by a combination of local conditions including short-term wind events, ocean surface currents and semi-diurnal tidal oscillations. A test of the assumption that icebergs drift at 2% of the wind speed indicates that this rule does not apply for the majority of icebergs in this study, which typically exceeded 2% of the wind speed, particularly at low values. The highest median iceberg drift speeds occurred during the winter and spring, reaching up to 2.3 m s⁻¹ in Nares Strait. Icebergs in this study commonly became grounded near eastern Coburg Island and along the SE coast of Baffin Island, where mean residence time exceeded 180 days in all seasons.
Through an analysis of a comprehensive database of ship tracks derived from AIS (automatic identification system) data in combination with a subset of iceberg drift locations derived from in-situ satellite trackers and the Canadian Ice Island Drift, Deterioration, and Detection Database (CI2D3), areas of iceberg-ship coexistence throughout Baffin Bay were identified between 2012 and 2019. The regions that saw the largest increases in iceberg-ship coexistence were along the east coast of Baffin Island and east of Bylot Island for dry bulk vessels, and northward into Smith Sound for passenger vessels. As passenger vessels commonly have little ice strengthening, this could pose an elevated hazard to vessels operating in these regions.
The results of this study provide a comprehensive examination of the factors controlling glacier terminus dynamics and stability on SE Ellesmere Island, and the drift paths of icebergs once calved. This provides insights into the life cycle of icebergs in Canadian waters, how they may change in a warming climate, and the hazards that they may pose for shipping, particularly given the rapid recent increase in ship transits across the Canadian Arctic.
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The circulation and fluxes from the Arctic into the North Atlantic Ocean 1979-2002 model resultsWilliams, Catherine E. 09 1900 (has links)
Approved for public release; distribution in unlimited. / The recent decreasing trend of sea ice cover in the Arctic region and its projected future reduction has direct implications for the global thermohaline circulation and the U.S. Navy. This thesis provides a qualitative and quantitative analysis of the freshwater export from the Arctic Ocean through the Canadian Arctic Archipelago (CAA) and the Fram Strait into the deep-water formation region of the Labrador Sea, using model data from 1979 to 2002. The results of this thesis directly aid the Navy in preparing personnel, ships, and weapons systems to operate efficiently in a possible ice-free Arctic. A coupled ice-ocean model of the pan-Arctic region at a 1/12-degree and 45-level grid resolution was used to produce data over a 24-year time period. The 24-year averaged annual velocity, temperature, and salinity profiles were compared for each of the analyzed stations. Additionally, 24-year mean monthly volume and freshwater flux time series plots and annual cycle plots were also produced to analyze the region's interannual variability from 1979 to 2002. The results show that the Canadian Arctic Archipelago is the major contributor of freshwater to the Labrador Sea. The CAA is a direct pathway for increased freshwater export from the Arctic into the sub-arctic seas where North Atlantic Deep Water(NADW)forms. The increased freshwater flux through the CAA, found in this study, supports the earlier reports on the freshening of NADW and a possibility of reduction in the meridional overturning rate in the North Atlantic. An increase in freshwater export from the Arctic is a good indicator of increasing sea ice reduction. The predicted opening of the Arctic to commercial and military vessels poses a direct threat to U.S. economical and strategic interests in the Arctic region. This thesis supports the U.S. Navy's ability to operate in a possibly ice-free Arctic. / Ensign, United States Navy
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Mission infrastructure development in the Canadian North, c. 1850-1920Turner, Emily Elizabeth January 2018 (has links)
This thesis explores the development of missionary infrastructure in the Canadian north between approximately 1850 and 1915 and its impact on the evangelization of northern indigenous people by missionary organizations. Focussing on two groups of missionaries - the Catholic Oblates of Mary Immaculate and the Anglican Church Missionary Society - this thesis demonstrates how missionaries used buildings to develop a programme for evangelization based on the convert and civilize model prevalent in nineteenth-century global missions. It argues that the intent was to convert indigenous people to Christianity and to enact significant changes on their traditional way of life, including their economy and social structure. Within this programme, architectural spaces, specifically the mission station, were used as a frontier location where indigenous people and missionaries interacted, providing a location for missionary teaching, a didactic place to demonstrate how Christians lived, and a method of transforming what was viewed as a non-Christian wilderness into a Christian 'garden' through construction of buildings and control of the natural world. While these ideas were applied to diverse locations throughout the global mission field in the early modern period of missionary activity, the Canadian north presents a unique area of study for this topic because of the relative lack of pre-existing non-indigenous development in the region, the difficulties in building resulting from its environment, and the romantic approach that missionaries took to it as the frontier of European and Christian activity - in biblical terms, the 'uttermost ends of the earth'. Within this context, the use of architecture as part of a missionary programme of conversion and civilization became extremely important as a tool for the transformation of the land and its people to a Christian ideal rooted in European precedent. This proved problematic because of the inherent difficulties in evangelization in this geographic region. As a result, this thesis demonstrates how missionaries applied architecture within the mission station as a tool for evangelization in this region, taking into consideration both the way in which they perceived the territory and the realities they faced on the ground. It reveals how these missionaries created a unique set of architectures that responded to how missionaries understood building function within the missionary environment, as well as what was actually achievable in the northern mission field.
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Numerical modelling of the ocean circulation in the Canadian Arctic ArchipelagoWang, Qiang Unknown Date
No description available.
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Timing and Mechanisms Controlling Evaporite Diapirism on Ellef Ringnes Island, Canadian Arctic ArchipelagoMacauley, Jennifer Anne 15 February 2010 (has links)
This thesis investigates the timing and mechanisms involved in the formation of evaporite piercement structures on Ellef Ringnes Island, Canadian Arctic Archipelago. The study includes the interpretation of industry seismic reflection and borehole data to characterize the geometry of the domes, 1D backstripping of wells to investigate the role of tectonic influences on diapirism, and analogue modelling to better understand the mechanisms that drive diapirs with dense anhydrite caps. I propose that basement structures played a significant role in the formation of evaporite domes by triggering and directing salt movement. The domes developed during the Mesozoic by passive growth driven by the differential loading of salt on adjacent fault blocks, which led to their present day asymmetric geometries. Diapir growth rates in the Mesozoic were closely linked to the rate of sedimentation, which was greatly influenced by the amount of accommodation space provided by tectonic subsidence of the basin.
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Timing and Mechanisms Controlling Evaporite Diapirism on Ellef Ringnes Island, Canadian Arctic ArchipelagoMacauley, Jennifer Anne 15 February 2010 (has links)
This thesis investigates the timing and mechanisms involved in the formation of evaporite piercement structures on Ellef Ringnes Island, Canadian Arctic Archipelago. The study includes the interpretation of industry seismic reflection and borehole data to characterize the geometry of the domes, 1D backstripping of wells to investigate the role of tectonic influences on diapirism, and analogue modelling to better understand the mechanisms that drive diapirs with dense anhydrite caps. I propose that basement structures played a significant role in the formation of evaporite domes by triggering and directing salt movement. The domes developed during the Mesozoic by passive growth driven by the differential loading of salt on adjacent fault blocks, which led to their present day asymmetric geometries. Diapir growth rates in the Mesozoic were closely linked to the rate of sedimentation, which was greatly influenced by the amount of accommodation space provided by tectonic subsidence of the basin.
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Using a Geospatial Approach to Evaluate the Impacts of Shipping Activity on Marine Mammals and Fish in Arctic CanadaJoyce, Jenna 14 June 2018 (has links)
A loss in sea ice cover, primarily attributed to climate change, is increasing the accessibility and navigability of the Arctic Ocean. This increased accessibility of the Canadian Arctic, and in particular the Northwest Passage, presents important global and national shipping and development opportunities. However, increased shipping in the region also present challenges related to the environmental sustainability, sovereignty and safety, and cultural sustainability. The Low Impact Shipping Corridors (the Corridors) is currently the foundational framework for governing ship traffic within the Canadian Arctic. However, the Corridors were largely established based on historic traffic patterns and thus they do not fully consider important areas for marine mammals and fish in the region. This research addresses this important research gap by spatially identifying important areas for marine mammals and fish in the Kitikmeot region of Nunavut using both Traditional Knowledge and western science, evaluating ship tracks from 1990-2015, and geospatially identifying and evaluating areas of potential disturbance for marine mammals and fish related to vessel noise from different ship types transiting the Corridors within the study region. The results of this study indicate that all vessel types have the potential to cause behavioural disturbance to marine mammals and fish when navigating through these important wildlife areas, and that louder vessels (i.e. Tanker ships) travelling outside of these important wildlife areas have a greater potential to cause behavioural disturbance to marine mammals and fish than quieter vessels (i.e. Pleasure Crafts). The results also indicate that vessels navigating through certain regions of the Kitikmeot have a higher potential to cause behavioural disturbances in these species, including through the Gulf of Boothia, Franklin Strait, Rae Strait, Rasmussen Basin, and Bathurst Inlet.
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On the freshwater transport through the southwest Canadian Arctic Archipelago due to buoyancy and wind forcingArfeuille, Gilles 08 November 2017 (has links)
The freshwater input from the Arctic into the North Atlantic is an important component
of the global climate system through its effects on deepwater formation. Part of this
freshwater is transported through the Canadian Arctic Archipelago (CAA) via sea ice and
low density surface water, where it is able to set up buoyancy boundary currents
(BBCs). To infer the existence of freshwater transport via BBCs in the southwest CAA,
data are examined from summer cruises conducted in 1995, 1999, and 2000. The
hydrographic data are supplemented with traditional knowledge relevant to this study.
The presence, predominantly on the south side of channels, of driftwood originating from
the Mackenzie River confirms an eastward transport through the region. The
hydrographic data also show that the southwest CAA is relatively fresh compared to
surrounding regions, and that the sources of buoyancy forcing are large and from different
origins. The presence of BBCs on both sides of the channels appears to be a frequent
occurrence with, as shown in previous work, the fresher water being more often present
on the south shore. Some data from the summer 2000 show a different feature with much
fresher water on the north side. A subsequent strong wind event creates a complete
reversal of this situation, setting up a strong cross-channel horizontal salinity gradient and
an amplified BBC on the south shore. In this region, buoyancy and wind forcing act
together to force an eastward freshwater transport in the southwest CAA. / Graduate
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A Transfer Learning Approach for Automatic Mapping of Retrogressive Thaw Slumps (RTSs) in the Western Canadian ArcticLin, Yiwen 09 December 2022 (has links)
Retrogressive thaw slumps (RTSs) are thermokarst landforms that develop on slopes in permafrost regions when thawing permafrost causes the land surface to collapse. RTSs are an indicator of climate change and pose a threat to human infrastructure and ecosystems in the affected areas. As the availability of ready-to-use high-resolution satellite imagery increases, automatic RTS mapping is being explored with deep learning methods. We employed a pre-trained Mask-RCNN model to automatically map RTSs on Banks Island and Victoria Island in the western Canadian Arctic, where there is extensive RTS activity. We tested the model with different settings, including image band combinations, backbones, and backbone trainable layers, and performed hyper-parameter tuning and determined the optimal learning rate, momentum, and decay rate for each of the model settings. Our final model successfully mapped most of the RTSs in our test sites, with F1 scores ranging from 0.61 to 0.79. Our study demonstrates that transfer learning from a pre-trained Mask-RCNN model is an effective approach that has the potential to be applied for RTS mapping across the Canadian Arctic.
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