|
|
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...
|
|
|
Paleoenvironmental significance of frost and ice wedges
Friedlová, Zuzana ; Křížek, Marek (advisor) ; Engel, Zbyněk (referee)
- Paleoenvironmental significance of ice and frost wedges This bachelor thesis deal with frost wedge and ice wedge pseudomorphs. At first part is summarized how and from are pseudomorphs formed. Therefore there is describe distribution and structure of permafrost, frost cracking, definition of ice wedges, their kinds and their transformation to pseudomorphs. Next part of this bachelor thesis describes morfological characteristic of polygons of frost wedge pseudomorphs at study area Šaratice. This polygons were compared with european pseudomorphs a then was deduced paleoclimatical and paleoenvironmetal reconstruction of their formation. Pseudomorphs are compared from their morphological characteristics too. Keywords: ice wedges, frost wedges, pseudomorphs of wedges
|
|
|
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...
|
guest ::
