Vertical electrical sounding

(Figure) The distribution of the current during the vertical electrical sounding

VERTICAL ELECTRICAL SOUNDING (EN: vertical electrosounding; DE: elektrisches Seigersondieren; FR: sondage vertical electrique; ES: sondeo electrico vertical; RU: вертикальное электрическое зондирование) is the method of the electrical exploration, which is based on the study of the dependence of the intensity of the constant electrical field on the distance between the two grounded (supplying) electrodes and the point for the measurement (the spacing within the installation). In case of the small spacings (up to 1-2 kilometres), the field within the point of observation depends on the structure of the upper part of the geological cross section (the depth is up to several hundred metres), while in case of the large spacings (up to several tens of kilometres), there increases the influence from the horizons with the depth of up to several kilometres (see the Figure). The vertical electrical sounding with the small spacings is performed with the lightweight portable apparatuses, within which there serve as the electrical supply the batteries for the electrical exploration; in case of the large spacings, there are used the stations for the electrical exploration with the engine generators.

As the parameter, which is characterizing the electrical structure of the geological cross section, there is used the so-named apparent electical resistance, where DU is the difference of the potentials between the two measuring electrodes (electrical groundings); I is the amperage; k is the coefficient, which depends on the mutual situation of the electrical groundings.

They represent the results from the vertical electrical sounding as the graphs for the dependence of the apparent resistance on the spacings within the installation. For the simple cross sections with the layers, which are embedded horizontally or with the slight inclination, the geological interpretation is performed using the comparison of the curves, which have been obtained, with the theoretical curves, which have been calculated for the cross sections with the given thicknesses of the layers, and with the given resistivities within these layers. As the result of the interpretation, they obtain the data about the thickness, resistivity, and other quantitative characteristics of the layers. During the study of the complicated cross sections with the steeply dipping boundary surfaces between the different rocks, the interpretation of the results has the qualitative character, and is limited to the identification of the geological structures, to the determination of their position as the projection onto the horizontal plane, of their direction of the dip, and so on.

<p>(Рисунок) Распределение тока при
вертикальном электрическом зондировании /
(Figure) The distribution of the current
during the vertical electrical sounding</p>

<p>VERTICAL ELECTRICAL SOUNDING (EN: vertical electrosounding; DE: elektrisches Seigersondieren; FR: sondage vertical electrique; ES: sondeo electrico vertical; RU:
вертикальное электрическое зондирование) is the method of the electrical exploration, which is based on the study of the dependence of the intensity of the constant electrical field on the distance between the two grounded (supplying) electrodes and the point for the measurement (the spacing within the installation). In case of the small spacings (up to 1-2 kilometres), the field within the point of observation depends on the structure of the upper part of the geological cross section (the depth is up to several hundred metres), while in case of the large spacings (up to several tens of kilometres), there increases the influence from the <a
href="http://www.mining-enc.ru/g/gorizont-gornyj/">horizons</a> with the depth of up to several kilometres (see the Figure). The vertical electrical sounding with the small spacings is performed with the lightweight portable apparatuses, within which there serve as the electrical supply the batteries for the electrical exploration; in case of the large spacings, there are used the stations for the electrical exploration with the engine generators.</p>

<p>As the parameter, which is characterizing the electrical structure of the geological <a
href="http://www.mining-enc.ru/r/razrez/">cross section</a>, there is used the so-named apparent electical resistance,

where DU is the difference of the potentials between the two measuring electrodes (electrical groundings);

I is the amperage;

k is the coefficient, which depends on the mutual situation of the electrical groundings.</p>

<p>They represent the results from the vertical electrical sounding as the graphs for the dependence of the apparent resistance on the spacings within the installation. For the simple cross sections with the <a
href="http://www.mining-enc.ru/p/plast/">layers</a>, which are embedded horizontally or with the slight inclination, the geological interpretation is performed using the comparison of the curves, which have been obtained, with the theoretical curves, which have been calculated for the cross sections with the given thicknesses of the layers, and with the given resistivities within these layers. As the result of the interpretation, they obtain the data about the thickness, resistivity, and other quantitative characteristics of the layers. During the study of the complicated cross sections with the steeply dipping boundary surfaces between the different rocks, the interpretation of the results has the qualitative character, and is limited to the identification of the geological structures, to the determination of their position as the projection onto the horizontal plane, of their direction of the dip, and so on.</p>