Theoretical and methodological substantiation of transient electromagnetic sounding from the Arctic drift ice

Marine geoelectromagnetic sounding with artificial sources is strongly hindered by the influence of a conductive seawater layer. There is only one known wide successful application of electrical prospecting in this field - Controlled Source Electromagnetic Method (CSEM). However, this method has unfortunate limitations: the need to submerge an electromagnetic probe to the bottom of a deep (more than 1000 m) sea and the great rafting (~15 km). The method is not applicable in an ice-covered sea. Deep sounding from the sea surface and, hence, from the ice surface is possible if the TM polarization field is used. This field is generated by a vertical electric line (VEL) or a circular electric dipole (CED). The former has drawbacks even when it is used at sea. At the same time, a CED is efficient in one-dimensional and three-dimensional media in frequency and time modes. We have developed a three-dimensional mathematical tool for the CED field in the Born approximation, which is quite adequate in a conductive section with deep local inhomogeneities. The research is carried out within the framework of a geophysical project using the Arctic driftices.