Geophysical Study of Lowland Permafrost in Komi-Nenets Area, North-West Russia

摘要

We present results of a 5-years (2007-2011) project aiming to new applications of electrical and electromagnetic (EM) ground and airborne techniques in permafrost studies. The study is based on geophysical measurements made at three lowland permafrost research areas and one mountain area, laboratory measurements of sediment samples and on geological and temperature borehole data from the research sites. The study areas are situated in the Northern Komi Republic and the Nenets Autonomous Area in Northwestern Russia (fig. 1a). The field EM and electrical resistivity (ERT) sounding data were inverted to 1D and 2D electrical conductivity models. Especially the electrical models from the lowland tundra area, based on the ERT data, show a very nice correspondence with the ground temperature. The electrical conductivity data collected for typical soils and sediments, both in frozen and in unfrozen state, is the basis for advanced use and interpretation of EM techniques and EM data, and for geophysical modeling of permafrost. The conductivity data give a possibility to calculate how, for example, a particular EM system would work at different kind of permafrost areas, i.e., what scale of structures and problems could be explored by it.