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Theses/Dissertations

2020

Arctic

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

A Periglacial Landsystem Analysis In The Canadian High Arctic: A Tool For Planetary Geomorphology, Chimira Nicole Andres Oct 2020

A Periglacial Landsystem Analysis In The Canadian High Arctic: A Tool For Planetary Geomorphology, Chimira Nicole Andres

Electronic Thesis and Dissertation Repository

Permafrost underlies 50% of Canada’s terrain and underlies 24% of the Earth’s total land area. It is a major driving force in the generation and evolution of patterned ground landforms such as polygons, stone circles, mud boils, and stripes, etc. that are seen on both the surface of the Earth and Mars, specifically in periglacial domains. The distribution of subsurface ice in these landforms (i.e. polygonal terrain) on Earth is a key constraint on past climate and process-form relationships in high arctic and periglacial regions. These landforms also have the potential of storing ice in the subsurface meaning that the …

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Snow-Albedo Feedback In Northern Alaska: How Vegetation Influences Snowmelt, Lucas C. Reckhaus Aug 2020

Snow-Albedo Feedback In Northern Alaska: How Vegetation Influences Snowmelt, Lucas C. Reckhaus

Theses and Dissertations

This paper investigates how the snow-albedo feedback mechanism of the arctic is changing in response to rising climate temperatures. Specifically, the interplay of vegetation and snowmelt, and how these two variables can be correlated. This has the potential to refine climate modelling of the spring transition season. Research was conducted at the ecoregion scale in northern Alaska from 2000 to 2020. Each ecoregion is defined by distinct topographic and ecological conditions, allowing for meaningful contrast between the patterns of spring albedo transition across surface conditions and vegetation types. The five most northerly ecoregions of Alaska are chosen as they encompass …

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Spatial And Temporal Distribution Of Essential And Non-Essential Elements Recorded In Western Arctic Bowhead Whales (Balaena Mysticetus), Samantha L. Shore Apr 2020

Spatial And Temporal Distribution Of Essential And Non-Essential Elements Recorded In Western Arctic Bowhead Whales (Balaena Mysticetus), Samantha L. Shore

HCNSO Student Theses and Dissertations

Western Arctic bowhead whales, Balaena mysticetus, migrate annually among the Bering, Chukchi, and Beaufort seas. Foraging along their route, they use keratinous baleen to filter microscopic zooplankton from the water column. A single baleen plate from an adult bowhead whale grows continuously and stores 20+ years of dietary and environmental data. This study utilized induced coupled plasma-mass spectrometry (ICP-MS) to evaluate concentrations of 14 essential and non-essential elements in baleen samples from nine subsistence-harvested whales, yielding continuous data from 1958–1999 (n=148). Stable isotope data previously reported on these samples provided information on location (Beaufort Sea; Bering/Chukchi seas), season (winter; …

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Impact-Generated Dykes And Shocked Carbonates From The Tunnunik And Haughton Impact Structures, Canadian High Arctic, Jennifer D. Newman Apr 2020

Impact-Generated Dykes And Shocked Carbonates From The Tunnunik And Haughton Impact Structures, Canadian High Arctic, Jennifer D. Newman

Electronic Thesis and Dissertation Repository

The Canadian High Arctic contains two impact structures created by hypervelocity impact events in carbonate-rich target rocks. The remote locations of the Tunnunik and Haughton impact structures means that there are aspects of these impact structures which have yet to be fully investigated. This study characterizes the range of impact-generated dykes exposed from both impact structures which include lithic breccias, impact melt-bearing breccias, and impact melt rocks. Breccias may include silicate impact glass fragments and evidence for carbonate melt. Impact melt rocks from the Haughton impact structure contain the rare terrestrial mineral moissanite. This is only the third reported occurrence …

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Higher Temperatures Have Contrasting Effects On Different Components Of Forage Quality For Caribou In Northern Alaska, Heidi Becker Jan 2020

Higher Temperatures Have Contrasting Effects On Different Components Of Forage Quality For Caribou In Northern Alaska, Heidi Becker

Electronic Theses and Dissertations

Rising temperatures in the Arctic may affect vegetation, which in turn can affect herbivores, such as caribou, that rely on these plants for forage. Several plant traits contribute to forage quality, including digestibility, nitrogen content, and antiherbivory secondary compounds, but the effect of temperature on these traits individually and combined is unclear. I conducted a three-component study on the effect of higher temperatures on the forage quality of graminoids, deciduous shrubs, and evergreen dwarf shrubs on the North Slope of Alaska. The components included: 1) short and long-term experimental warming, 2) natural temperature variation between south and north-facing slopes, and …

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