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GEO EXPLORATION TECHNOLOGIES has distinguished experience in performing 2D geoelectrical imaging and maintains newest geoelectric equipment in combination with many electrodes equipment controlled by GeoTest software.

This type of geoelectric measurement is called "Multi-Electrode Geoelectrics". Using two-dimensional or three-dimensional inversion techniques additionally for evaluation, this method is known as "Geoelectric Tomography" (Geoelectrical Imaging).

Geoelectric tomography is a modern type of 4-point geoelectrics. "4 point" means, for one measurement always four electrodes are used. Two electrodes serve as current emitting electrodes. These are usually named A and B. Two other electrodes measure the potential difference (= voltage). These are the M and N electrodes.

The measurements can be done in two principal different orientations.

• Profiling: this means measurements, where the electrodes are set along a linear profile on the Earth surface. The measurement profile is 1-dimensional (e.g. in x direction) and the result will be a 2-dimensional depth section, which is a plane in e.g. x- and z-direction.

•   Mapping: the electrodes are set along a 2-dimensional grid on the Earth surface. The measurements are done in a 2-dimensional plane (e.g. in x- and y-directions). The result will be a 3 dimensional block containing x-, y- and z- coordinates.

The following figure 1 show some explanation of the technique using multicore cables to measure one geoelectric profile ("profiling").

 Multi-Electrode measurement principle

Multi-Elektrode-Array

results: depths till 30 m