Criteria of the Influence of Climatic Factors on the Condition of Frozen Foundations by Geophysical Data

Apparent resistivity in the frequency range of 100-1000 kHz and soil electromagnetic emission parameters in the frequency range of 1-300 kHz are proposed to be used as criteria for assessing the influence of climatic factors on the condition of permafrost foundations. The addition of traditional measurements of soils temperature by measurements of their apparent resistivity raises information maintenance of monitoring. The joint consideration of effective resistance and temperatures gives more complete representation about changes of a soils condition, climatic factors, occurring as result of influence. By monitoring apparent resistivities, it is possible not only to assess the degree of soil freezing, but also to take into account changes in volumetric ice content (moisture content) and other physical properties. Apparent resistivity can also be used to detect and estimate the influence of such climatic factors, as rainfall and snow depth. The phenomenon of electromagnetic emission in frozen ground is shown to be an indicator of on-going processes of thawing or freezing. Electromagnetic emission parameters are thus useful for assessing intensity and duration of soil thawing and freezing.