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Geophysical Surveys

Perfil de tomografía eléctrica
Perfil de tomografía eléctrica

The study subsurface using geophysical techniques allows rapid analysis of soil characteristics, especially, the presence of cavities, thickness of aquifers and soils. These techniques provide the added value of being faster and cheaper than mechanical surveys and can cover larger areas.

Also facilitate the diagnosis and to adjust the costs of field campaigns. Troubleshooting and structures for modeling industrial mineral deposits and aggregates, archaeological sites and to detect water levels and pollution plumes.

-. Electrical Techniques:

  • Vertical electrical sounding S.E.V.
  • Testing of electrical resistivity to earth ground according to ASTM G 57 and IEEE Std 81-2012.
  • Electrical tomography ETR:
    • Detection of cavities: Currently the electric tomography is the most used for detecting cavities indirect method. It is a non-destructive method able to cover large areas of research.
    • Civil work. The electric tomography is a highly useful additional information for modeling of geological structures, lateral changes in water levels saturated, fractured rock areas, karstificaciones, etc …
    • Studies for earthing for electrical substations SET: get tomography by electrical soil resistivity, and therefore is considered as a method for obtaining the geoelectric soil characteristics for design of grounding.
    • Other applications: Modeling of aggregates and industrial minerals, geoarchaeology, detection of contaminated soils and hydrogeology.

-. Electromagnetic techniques:

  • CMD-Explorer (Multi Depth Electromagnetic Conductivity Meters). Electrical resistivity test using electromagnetic device. This method is highly recommended for desert areas with very low moisture content, where almost dielectric nature of the top layer of soil in the area to investigate very difficult communication between the electrodes (electrical method) and means that it can not take action reliable resistivity specified distances between electrodes. Therefore, alternatively it is used to measure resistivities from electromagnetic fields due to this technique does not affect the nature of the dielectric material.
Ensayos de resistividad mediante método electromagnético en zonas desérticas. Foto: Desierto de Atacama, Chile.
Ensayos de resistividad mediante método electromagnético en zonas desérticas. Foto: Desierto de Atacama, Chile.

-. Seismic techniques:

  • Downhole tests. Variation of the propagation velocities of P and S waves Determination of elastic moduli.
  • MASW (Multichannel Analysis of Surface Waves). Speed models S waves high resolution.
  • Seismic tomography and seismic refraction profiles.

-. Thermal resistivity:

  • Thermal resistivity testing to earth ground according to ASTM D5334.