CGRG Bibliography of Canadian Geomorphology
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Author : Fortier, R.; and Allard, M.
Date : 1998
Title : Induced polarization and resistivity logging in permafrost
Publication : Permafrost, Seventh International Conference, June 23-27, Yellowknife, Canada. Edited by: A.G. Lewkowicz and M. Allard. Université Laval, Centre d'études nordiques, Collection Nordicana.
Issue : 57:
Page(s) : 275-282.
Abstract
Induced polarization (IP) and resistivity logs were carried out in a permafrost plateau near Umiujaq, Northern Québec, to outline the permafrost dynamics. A permanently buried multiconductor cable into permafrost, with regularly spaced electrodes and thermistors, was used for IP, resistivity and temperature logging. The cryofronts in the active layer and at the permafrost base corresponded to resistivity values around 500 ohm-m. A basal cryopeg was clearly delimited between 21 and 22.7 m in depth by a sharp decrease in resistivity from 2000 to 500 ohm-m close to 21 m and a sharp increase in total chargeability from -4 mV/V in permafrost to values over -16 mV/V in the basal cryopeg. The freezing-point depression due to overburden pressure at the base of perennially frozen layer is evaluated to be -0.2°C. Resistivity values higher than 60,000 ohmm were measured in permafrost. Decrease in resistivity with time was monitored due to permafrost warming during summer 1990.
Bibliography of Canadian Geomorphology