| Title | Characteristics of discontinuous permafrost based on ground temperature measurements and electrical resistivity tomography, southern Yukon, Canada |
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| Author | Lewkowicz, A G; Etzelmuller, B; Smith, S L |
| Source | Permafrost and Periglacial Processes 2011, 23 pages, https://doi.org/10.1002/ppp.703 |
| Image |  |
| Year | 2011 |
| Alt Series | Earth Sciences Sector, Contribution Series 20100083 |
| Publisher | Wiley-Blackwell |
| Document | serial |
| Lang. | English |
| Media | on-line; digital; paper |
| File format | pdf |
| Province | Yukon |
| NTS | 105C; 105D; 115O |
| Area | Dawson; Indian River; Wolfe Creek; Teslin; Whitehorse; Mayo Road; Johnson's Crossing |
| Lat/Long WENS | -136.0000 -132.0000 61.0000 60.0000 |
| Lat/Long WENS | -140.0000 -138.0000 64.0000 63.0000 |
| Subjects | surficial geology/geomorphology; geophysics; environmental geology; Nature and Environment; permafrost; freezing ground; ground ice; ground temperatures; electrical resistivity; resistivity; climate,
arctic; climate; climatic fluctuations; Climate change |
| Illustrations | location maps; tables; profiles; photographs |
| Program | Climate Change Geoscience |
| Released | 2011 06 08 |
| Abstract | Warm permafrost conditions (mean temperatures of -3°C to -0.1°C) were investigated in detail at 13 valley and mountain sites in the sporadic (10 - 50%) and extensive (50 - 90%) discontinuous permafrost
zones in the southern half of the Yukon (60°N to 64°N), using a combination of ground temperature monitoring, electrical resistivity tomography (ERT), frost table probing and coring. Sites were selected to cover a wide range of substrates, vegetation
types and ground ice contents. ERT profiling in the spring imaged both deep seasonal frost and perennially frozen ground. Deep active layers measured by probing at the end of summer were also detectable by ERT. Where ground temperatures indicated
that the base of permafrost was at a depth of less than 25 m, vertical transitions in apparent resistivity were more sharply defined in coarse materials than in fine-grained deposits, probably because of differences in unfrozen moisture contents at
temperatures just below 0°C. Apparent resistivity values related to excess ice fraction and ground temperatures were similar to those previously obtained in Mongolia and Iceland, but generally lower than in ice-rich rock glaciers in European studies.
The observations revealed the complexity of site conditions where permafrost is discontinuous and the utility of ERT, in combination with other methods, to investigate permafrost thickness, spatial extent and ice content for infrastructure planning
or climate change studies. |
| GEOSCAN ID | 285588 |
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