MUDBOIL AND ICE‐WEDGE DYNAMICS INVESTIGATED BY ELECTRICAL RESISTIVITY TOMOGRAPHY,GROUND TEMPERATURES AND SURFACE MOVEMENTS IN SVALBARD |
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| Authors: | TATSUYA WATANABE NORIKAZU MATSUOKA HANNE H CHRISTIANSEN |
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| Institution: | 1. Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan;2. Department of Geology, The University Centre in Svalbard, UNIS, Longyearbyen, Norway;3. Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan |
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| Abstract: | Arctic tundra surfaces are dominated by a variety of patterned ground forms. Whereas a large number of studies have described morphology, structure and processes of patterned ground, few have monitored detailed patterned ground dynamics and subsurface environments continuously. We applied electrical resistivity tomography (ERT) to understand near‐surface conditions of two types of patterned ground, ice‐wedge polygons and mudboils in Svalbard, where periglacial processes associated with permafrost are intensively monitored. Automated monitoring shows surface movement characterized by annual cycles of frost heave and thaw settlement, the amounts and rates of which are influenced by the intensity of ice segregation. A time series of ERT shows (1) a distinct resistivity boundary delimiting the active‐layer depth, (2) seasonal variation in resistivity controlled by thermo‐hydrological dynamics and (3) spatial variation in resistivity reflecting desiccation in summer and intensive ice segregation in winter. These results demonstrate ERT as a useful complementary technique for monitoring active‐layer depths and near‐surface hydrological conditions at periglacial patterned ground sites, where automated soil thermal and moisture measurements are limited. |
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| Keywords: | active layer electrical resistivity tomography patterned ground permafrost Svalbard |
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