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Electrical resistivity tomography (ERT) or electrical resistivity imaging (ERI) is a geophysical technique for imaging sub-surface structures from electrical resistivity measurements made at the surface, or by electrodes in one or more boreholes. If the electrodes are suspended in the boreholes, deeper sections can be investigated.
Electrical resistance surveys (also called earth resistance or resistivity survey) are one of a number of methods used in archaeological geophysics, as well as in engineering geology investigations. In this type of survey electrical resistance meters are used to detect and map subsurface archaeological features and patterning.
Electrical resistivity tomography profile. The reciprocal of conductivity, electrical resistivity surveys measure the resistance of material (usually soil) between electrical probes, with typical penetration depths one to two times the electrode separations. There are various electrode configurations of equipment, the most typical using two ...
Electrical techniques, including electrical resistivity tomography and induced polarization. Electromagnetic methods, such as magnetotellurics, ground penetrating radar, transient/time-domain electromagnetics, and SNMR. Borehole geophysics, also called well logging. Remote sensing techniques, including hyperspectral imaging.
The polarization effect was originally discovered by Conrad Schlumberger when measuring the resistivity of rock. [3] The survey method is similar to electrical resistivity tomography (ERT), in that an electric current is transmitted into the subsurface through two electrodes, and voltage is monitored through two other electrodes.
Measuring electrical resistivity allows different materials and structures to be distinguished from one another and can improve knowledge of tectonic processes and geologic structures. The Earth's naturally varying electric and magnetic fields are measured over a wide range of magnetotelluric frequencies from 10,000 Hz to 0.0001 Hz (10,000 s ...
Electrical impedance tomography (EIT) is a noninvasive type of medical imaging in which the electrical conductivity, permittivity, and impedance of a part of the body is inferred from surface electrode measurements and used to form a tomographic image of that part. Electrical conductivity varies considerably among various types of biological ...
EIT and ERT – Electrical impedance tomography and electrical resistivity tomography; EL – Electroluminescence; Electron crystallography; ELS – Electrophoretic light scattering; ENDOR – Electron nuclear double resonance, see ESR or EPR; EPMA – Electron probe microanalysis; EPR – Electron paramagnetic resonance spectroscopy