Exploration Methods: Electric
Electrical methods are used to describe those geophysical methods using electric current to characterize the subsurface. It is an artificial field method; this means that the electric field should be generated and transmitted to the ground and there should be receptors capable of capturing the response associated with such interaction. This condition implies that it is required to have transmitters and receivers, with a consequent increase in instrumentation and personnel compared with methods that measure natural fields. It is only executable in land acquisitions.
The methods of artificial field have the advantage of allowing the orientation of the induced field. Its limitation lies in the penetration range, since it depends on the power of the source and composition or electrical properties of the subsurface. The resolution range of these methods ranges from centimeters in archeology to hundreds of meters in mining.
The electrical methods are applied widely for groundwater exploration, mining and geotechnics. The different source-receiver arrangements that can be configured allow describing variations of electrical resistivity in depth, known as a vertical electrical sounding (VES) application, and also to display the lateral variations of electrical resistivity, application identified aselectrical profiling. The combination of the configurations described also allows the implementation of electrical tomography studies.