00000nam 2200000za 4500 9.833594 CaOODSP 20251031142447 cr ||||||||||| 170309s2017 oncabd ob f000 0 eng d CaOODSP eng n-cn-nt M183-2/8124E-PDF Fish, C. S. Icings in the Lac la Martre area (1984–2015), Northwest Territories, mapped from Landsat imagery [electronic resource] / C.S. Fish, P.D. Morse, and S.A. Wolfe. [Ottawa] : Natural Resources Canada, c2017. 43 p. : charts, ill. (mostly col.), maps (mostly col.) Open file ; 8124 Includes bibliographical references (p. 38-39). "Icings are sheet-like masses of layered ice that form over the winter by freezing of successive flows of water on the ground surface or on top of river or lake ice. Icings can negatively impact the performance of seasonal and all-season roads and are a transportation risk in Arctic regions. Therefore, maps of their occurrence and reoccurrence provide important geoscience information required for development and transportation infrastructure planning. In this study, a set of icing maps was derived using threshold values of band ratios from a time series of Landsat images (1984 – 2015), located within the Bear and Interior Platform Geological Provinces in the Lac la Martre area, NWT (WRS-2 Path 49/Row 16). The icings maps were generated using images acquired in late spring when the region is largely snow-free, but ice bodies remain. A water mask created from summer images was used to differentiate between different types of frozen water bodies (rivers, lakes, icings), so any remaining ice was considered to be icings. Icing reoccurrence maps were generated by overlaying successive icing distribution maps in a Geographic Information System. This Open File contains the digital, georeferenced icing data"--Abstract, p. 3. gccst Ice gccst Hydrogeology gccst Cartography gccst Satellite imagery Morse, Peter Douglass, 1975- Wolfe, Stephen Andrew, 1963- Canada. Natural Resources Canada. Geological Survey of Canada. Open file (Geological Survey of Canada) 8124 (CaOODSP)9.506878 PDF 1.36 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M183-2/M183-2-8124-eng.pdf 299737