The nature and dynamics of frozen ground in alpine and subarctic periglacial environments
A spatial assessment of the complex discontinuous and sporadic permafrost distribution and characteristics in high-altitude alpine and high-latitude subarctic permafrost environments was achieved using a combination of different methodological approaches consisting of traditional (geomorphological m...
| Published in: | The Holocene |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
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SAGE Publications
2010
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1177/0959683609353432 http://journals.sagepub.com/doi/pdf/10.1177/0959683609353432 |
| Summary: | A spatial assessment of the complex discontinuous and sporadic permafrost distribution and characteristics in high-altitude alpine and high-latitude subarctic permafrost environments was achieved using a combination of different methodological approaches consisting of traditional (geomorphological mapping) and modern techniques (2D near surface geophysics, surface and subsurface temperature monitoring). For the study of alpine and subarctic mountain permafrost with small-scale heterogeneity of surface and subsurface characteristics electrical resistivity tomography (ERT) has proven to be an especially well-suited and multifunctional method. Synoptic comparison of the nature and dynamics of frozen ground in alpine and subarctic periglacial environments confirmed heterogeneous and patchy permafrost occurrences showing a strong relationship to the surface textural characteristics and snow cover distribution and duration. Concerning frozen ground dynamics there is geomorphological and geophysical evidence for permafrost aggradation and degradation. At present both processes are possible in the investigated study areas with small-scale variation of the environmental factors. It can be concluded that permafrost with a timescale varying from several decades to a few thousand years can coexist in close proximity, such as, for instance, subrecent permafrost formation in a recently exposed glacier forefield and Holocene push moraines and rock glaciers. In order to account for the small-scale heterogeneity geomorphological field observations, geophysical mapping and multiple in situ measurements are required to understand complex periglacial environments, to monitor the contemporary permafrost conditions and enable a differentiation between interannual fluctuations from long-term trends. Such integrated approaches are thought to have the potential to improve the understanding of the Holocene and subrecent landscape evolution in complex glacial and periglacial environments which may exhibit active, inactive and relict ... |
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