In such environments, the conventional seismic methods often provide marginal results and new exploration approaches need to be defined.
To Magnetotellurics MT / AMT, the conditions which cause difficult seismic energy propagation are largely irrelevant and so the method readily images the resistivity of the sub-surface.
Ideal targets include resistive carbonate reservoirs below shale or flysch and clastic reservoirs below salt bodies. Integration of seismic, gravity and magnetotellurics MT leads to improved velocity-model building for outcropping carbonates, thrust sheets, sub-basalt, and sub-salt for seismic, passive seismic (IPSS and PST) imaging, as well as to better resistivity estimates for magnetotellurics MT interpretation.
The contrast of resistivity provides an excellent tool for identifying geothermal targets.
The data acquisition system has a receiver unit (Unit MT), two electromagnetic sensors, and four electrodes the placement of 4 electrodes arranged in a cross the disposition of the two orthogonal magnetic sensors at a distance of about 25 m from the instrument receiver.
The magnetotellurics surveys reach great depths in confined spaces.