Green Technologies offers geoseismic studies using the Seismic Refraction Trends technique, which basically consists of measuring known points along the ground surface and the transit time of longitudinal compressional waves (P waves) generated by an energy source. At a known point, these times are measured as pulses on the Seismograph from which distance and travel time data are converted to velocity and depth data. The speed depends on the elastic modulus of the soil.

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If the interfaces in the subsoil were flat, the value of the velocities could be read directly from the graph, but in reality they are not always flat, so it is required to have direct and inverse time-distance curves in order to obtain the real velocity of each stratum in the subsoil.

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