magnetic variation profiling magnetotelluric sounding магнітоваріаційне профілювання electric conductivity anomaly geomagnetic variations horizontal magnetic tensor induction vector геомагнітні варіації 11-year variation of the induction vector Archean and Proterozoic geoblocks Carpathian electrical conductivity anomaly Earth electrical conductivity Karpinsky swell Precambrian Shields Wiese induction vector absolute motion annual variations of induction vectors deep geoelectrics degassing of the Earth and the Moon diurnal geomagnetic variations earthquake precursors earthquakes precursors electric conductivity of lithosphere electrical conductivity anomalies electrical conductivity of the Moon and the Earth electrical properties electromagnetic response functions electromagnetic theory folded Donbas geomagnetic induction