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Full-Text Articles in Physical Sciences and Mathematics
Controls On Thermokarst Lake Water Balances In The Inuvik - Tuktoyaktuk Region, Evan J. Wilcox
Controls On Thermokarst Lake Water Balances In The Inuvik - Tuktoyaktuk Region, Evan J. Wilcox
Theses and Dissertations (Comprehensive)
There are tens of thousands of thermokarst lakes in the Inuvik-Tuktoyaktuk region, located in the northwest corner of the Northwest Territories, Canada. These lakes formed following the last glacial period in areas where ice-rich permafrost thawed and created depressions in the landscape. The Inuvik-Tuktoyaktuk region is one of the fastest warming regions in the world, leading to changing precipitation patterns, permafrost thaw and deciduous shrub expansion, all of which are affecting the water balance of thermokarst lakes. During the past several decades, lake expansion and contraction have been observed in response to fluctuations in precipitation. While these changes in lake …
Alpine Shrub Tundra Water Storage And Runoff Dynamics In The Mackenzie Mountains, Sahtú Territory, Nt, Geoffrey Kershaw
Alpine Shrub Tundra Water Storage And Runoff Dynamics In The Mackenzie Mountains, Sahtú Territory, Nt, Geoffrey Kershaw
Theses and Dissertations (Comprehensive)
Alpine regions receive large volumes of precipitation and are important to local and regional water balances, particularly during baseflow periods of winter cold and summer drought when the larger basin area is frozen and/or water limited. Alpine headwaters in western Canada are expected to warm and receive more precipitation during the coming decades, with implications for groundwater recharge and streamflow generation within these systems and the regional river networks to which they contribute. Throughout the North, thawing peat plateaus and other ice-rich permafrost features are resulting in an increased extent of thermokarst and wetland land cover. This transition places infrastructure …
An Evaluation Of Ground-Freezing Methods In The Zone Of Discontinuous Permafrost, Northwest Territories, Elzbieta Mastej Ms
An Evaluation Of Ground-Freezing Methods In The Zone Of Discontinuous Permafrost, Northwest Territories, Elzbieta Mastej Ms
Theses and Dissertations (Comprehensive)
Northwestern Canada is one of the most rapidly warming regions on Earth. The southern limit of the discontinuous permafrost zone is highly sensitive to small climatic fluctuations and presently experiencing a rapid landscape change due to accelerated permafrost thaw, which is further exacerbated by anthropogenic disturbances such as seismic exploration. Recent research has begun to examine both natural and mechanical approaches to minimize permafrost loss, although the utility of such methods in peatland environments is not well understood. This study explored the efficiency of natural and artificial ground cooling processes in a peatland environment by evaluating snow exclusion and thermosyphon …
Biogeochemical And Hydrological Impacts Of A Low-Severity Wildfire In The Wetland-Dominated Zone Of Discontinuous Permafrost, Caren J. Ackley
Biogeochemical And Hydrological Impacts Of A Low-Severity Wildfire In The Wetland-Dominated Zone Of Discontinuous Permafrost, Caren J. Ackley
Theses and Dissertations (Comprehensive)
Northern regions are experiencing rapid climate warming. As these regions warm, the occurrences of naturally ignited wildfires are increasing in frequency, severity and area burned, calling for a more thorough understanding of post-fire eco-hydrological impacts. Changes in runoff chemistry, and soil moisture and thermal regimes, have been attributed to the significant loss of organic matter (OM) and exposure of deeper soils, leading to enhanced permafrost degradation, ground surface subsidence and the conversion of peat landscapes from long-term C sinks to sources. However, low-severity wildfires often result in minor OM loss. Due to the significant and immediate threats posed to the …
Impact Of Linear Disturbances On A Discontinuous Permafrost Peatland Environment, Michael Braverman
Impact Of Linear Disturbances On A Discontinuous Permafrost Peatland Environment, Michael Braverman
Theses and Dissertations (Comprehensive)
Permafrost is ground that remains at or below 0°C for at least two consecutive years (PIWP, 2012). In the continuous permafrost zone its thickness may exceed 300 m, in lower latitudes, permafrost thickness is progressively decreasing, its occurrence becomes discontinuous and eventually sporadic (PIWP, 2012). At the southern fringe of permafrost in northwestern Canada, just about few meters. In subarctic peatlands permafrost is one of the main elements governing the hydrological processes. Being very thin and with temperature just fractions of the degree below 0oC, it is very vulnerable to any changes in soil temperature and water content. …
Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman
Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman
Theses and Dissertations (Comprehensive)
Peat-accumulating wetlands are ecosystems whose rate of photosynthetic production of organic matter is greater than that of its decomposition, resulting in a build up of soil organic matter that may take centuries to fully decompose. Carbon (C) stocks within these ecosystems are a function of inputs from photosynthesis, and losses from heterotrophic decomposition. Due to the short growing season and overall cold climate of boreal and tundra regions, C has been accumulating within these landscapes, mostly in soil organic matter, since the last glaciation. Climate change, predicted to result in rising temperatures and increased precipitation, has begun to degrade the …