The geophysical methods allow us to infer the geologic structure of the subsoil, using some properties of the physics of the subsoil which can be measured from the surface, thus determining its spatial distribution.
Among the physical properties of the subsoil, its electrical resistivity, speed of propagation of sound waves, density of mass and magnetic susceptibility can be mentioned as the most important. For these properties we have geological, seismic, gravimetric and magnetometric methods.
This method determines the electrical characteristics of the subsoil, using a profile of electrodes which are introduced into the soil and fed with current so that it propagates through the subsoil, which gives a record of the resistivity which allows determining the type of material that composes it and the discontinuity between the different layers of the subsoil.
This method is effective in the detection of groundwater, saline intrusion, studies of archaeological zones, detection of pollutants by hydrocarbons and determine the stratigraphy of the soil among others.
This type of method generates seismic waves artificially by a hammer or weight drop, recorded by means of geophones distributed in a suitable way in the terrain, to be analyzed, recording the propagation speed of waves in the subsoil.
Among the techniques used are the seismic refraction, reflection, surface seismic tomography and passive seismic REMI. These techniques are used to determine the depth of healthy rocks and characterize the rocky basement, determine the stratigraphy of the subsoil, elastic parameters of the subsoil and groundwater detection among others.