Nonlocal electromagnetic response: Implications in the regional sounding

Due regard was given to the nonlocal electromagnetic responses in the processing of the data of the International Baltic Electromagnetic Array Research (BEAR) 1998 Project. Maps of lateral distributions of the apparent electrical resistivity for different time periods were compiled. In these maps, the main tectonic boundaries between the Lapland-Kola, Karelian, and Svecofennian tectonic provinces within the Baltic Shield appear as zones with reduced apparent electrical resistivity. There is supposedly some correlation between the positions of the maxima in electrical resistivity and the maximum Moho depths. In the same way, the data from the network of geomagnetic observatories in the European region (the INTERMAGNET Project) were processed for 2004–2005, and maps of the laterally inhomogeneous distribution of the apparent resistivity in Europe have been compiled for different time periods. The correlation is observed between the positions of the minima in the electrical resistivity and the minima in the thickness of the lithosphere.