Geoelektrik

Geoelektrik, often referred to in English as geoelectric studies, is a field of geophysics and engineering that investigates the electrical properties of the subsurface to characterize rock, fluid content, and structure. By measuring how rocks and soils conduct or resist electric currents, researchers can infer properties such as porosity, mineralogy, salinity in groundwater, and the presence of fluids or hydrocarbons.

The main methods include electrical resistivity tomography (ERT) with 2D or 3D arrays, vertical electrical sounding, and magnetotellurics. Induced polarization enhances detection of metallic minerals, while self-potential measurements can reveal groundwater flow and hydrogeological processes. Data are inverted to produce spatial models of conductivity or resistivity, which must be interpreted in light of geology and borehole information.

Geoelektrik has wide applications: mapping aquifers and hydrological properties, delineating contamination plumes, exploring mineral deposits and geothermal reservoirs, supporting civil engineering projects and environmental assessments, and contributing to archaeological surveys where buried features affect conductivity contrasts.

The approach is non-invasive and cost-efficient relative to some other geophysical methods, and it is particularly sensitive to fluids and lithology. Its limitations include non-uniqueness of inversion results, resolution that decreases with depth, sensitivity to soil moisture, temperature, and noise, and the need for careful calibration and integration with other data sets.

The field emerged in the early 20th century as electrical methods were applied to geological problems, and it has since evolved with advances in instrumentation, data processing, and modeling. Today geoelektrik is used by researchers, environmental agencies, and industry practitioners worldwide to better understand subsurface conditions. See also geophysics, electrical resistivity, magnetotellurics.