MIGRATION OF THE SCALAR COMPONENTS OF THE ELECTROMAGNETIC FIELD IN GEOELECTRIC PROBLEMS

Abstract

We have developed a migration method for scalar components of the electromagnetic field that can be used to reconstruct the locations of geoelectric nonuniformities from the measured components of the magnetic or electric field. This method decreases the number of needed observations significantly below that required in the general method of electromagnetic migration. The latter also requires measurements of vectors of the unsteady-state electromagnetic field. The method can be used to interpret electromagnetic sounding made with a powerful pulse current generator and to process standard geophysical investigations by transient field sounding technique. The migration transformations can be used to transform the electromagnetic fields observed at the ground surface into a 'geoelectric image' of the geological section, as well as to identify the positions of conductive bodies associated with hydrothermal phenomena or the presence of potential ore-containing zones.