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Morphological feattures of ice wedge polygons in arctic zone.
Kysilka, Tomáš ; Křížek, Marek (advisor) ; Treml, Václav (referee)
Morphological features of ice wedge polygons in arctic zone Abstract This bachelor thesis deals with the subject of ice-wedge polygons including theirs morphological characteristics and conditions prerequisite for their creation. The paper states the conditions which allow and inhibit frost cracking of the ground. First part presents the conclusions of scientific literature published on the topic of permafrost, frost cracking, ice- wedges and ice-wedge polygons. Consequently the paper discusses the relation of ice-wedge polygons morphology to climate and lithology. Further the thesis analyzes morphological characteristics of ice-wedge polygonal net localized at southwest part of Banks Island, Canadian Arctic Archipelago. Acquired data and conclusions are confronted with published periglacial literature. Keywords: ice-wedge, ice-wedge polygons, frost cracking, permafrost, Banks Island, arctic zone
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Geomorphologica and climatic factors influencing morphological features of ice wedge polygons in arctic zone
Kysilka, Tomáš ; Křížek, Marek (advisor) ; Marvánek, Ondřej (referee)
Location and climate factors governing morphological features of ice wedge polygons in arctic zone Abstract This thesis reports the geometry of active soil and ice-wedge polygonal network located along the Canadian Arctic and in Alaska. This High Arctic periglacial environment was chosen to ensure active thermal-contraction cracking of permafrost in Holocene allowing comparison of observed ice-wedge polygons with existing climatic data. Geoinformatic software (Google Earth, ArcGIS) was used to obtain and digitalize satellite images of polygonal networks located around Eureka, Mould Bay, Churchill, Rankin Inlet, Inuvik, and Kotzebue. Defined polygonal networks were statistically analyzed in order to define predominant environmental factors controlling morphological parameters of these polygonal networks. Polygon size (overall influence computed on the basis of coefficient of determination) is determined mostly by the duration of development (18 %), frequency of cyclonic passage (17.8 %) and winter air temperature (16.1 %). Conversely, polygon regularity results mainly from nature of the substrate (21.8 %), winter wind speed (15.1 %) and snow cover thickness (12.2 %). Dominant polygon elongation in the polygonal network follows closely the winter wind direction (3/4 of all networks) as the result of snow...
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Geomorphologica and climatic factors influencing morphological features of ice wedge polygons in arctic zone
Kysilka, Tomáš ; Křížek, Marek (advisor) ; Marvánek, Ondřej (referee)
Location and climate factors governing morphological features of ice wedge polygons in arctic zone Abstract This thesis reports the geometry of active soil and ice-wedge polygonal network located along the Canadian Arctic and in Alaska. This High Arctic periglacial environment was chosen to ensure active thermal-contraction cracking of permafrost in Holocene allowing comparison of observed ice-wedge polygons with existing climatic data. Geoinformatic software (Google Earth, ArcGIS) was used to obtain and digitalize satellite images of polygonal networks located around Eureka, Mould Bay, Churchill, Rankin Inlet, Inuvik, and Kotzebue. Defined polygonal networks were statistically analyzed in order to define predominant environmental factors controlling morphological parameters of these polygonal networks. Polygon size (overall influence computed on the basis of coefficient of determination) is determined mostly by the duration of development (18 %), frequency of cyclonic passage (17.8 %) and winter air temperature (16.1 %). Conversely, polygon regularity results mainly from nature of the substrate (21.8 %), winter wind speed (15.1 %) and snow cover thickness (12.2 %). Dominant polygon elongation in the polygonal network follows closely the winter wind direction (3/4 of all networks) as the result of snow...
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Morphological feattures of ice wedge polygons in arctic zone.
Kysilka, Tomáš ; Křížek, Marek (advisor) ; Treml, Václav (referee)
Morphological features of ice wedge polygons in arctic zone Abstract This bachelor thesis deals with the subject of ice-wedge polygons including theirs morphological characteristics and conditions prerequisite for their creation. The paper states the conditions which allow and inhibit frost cracking of the ground. First part presents the conclusions of scientific literature published on the topic of permafrost, frost cracking, ice- wedges and ice-wedge polygons. Consequently the paper discusses the relation of ice-wedge polygons morphology to climate and lithology. Further the thesis analyzes morphological characteristics of ice-wedge polygonal net localized at southwest part of Banks Island, Canadian Arctic Archipelago. Acquired data and conclusions are confronted with published periglacial literature. Keywords: ice-wedge, ice-wedge polygons, frost cracking, permafrost, Banks Island, arctic zone
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