Geophysical methods
The geophysical methods allow us to infer the geologic structure of the subsoil using for it some property of the physics of the subsoil that can be measured from the surface, thus determining its spatial distribution.
Among the physical properties of the subsoil we can mention the electrical resistivity, speed of propagation of sound waves, density of mass and magnetic susceptibility as the most important. Starting from these properties we have geological, seismic, gravimetric and magnetometric methods.
Geoelectric methods
In this method, it determines the electrical characteristics of the subsoil using a profile of electrodes that 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, determine the stratigraphy of the soil among others.
Seismic Methods
In this type of method seismic waves are generated artificially by a hammer or weight drop that are recorded by means of geophones that are 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, groundwater detection among others.
