Some results of observations of the ELF field's magnetic component at the Ukrainian Antarctic Station «Akademic Vernadsky» are presented which cover a period of May 2001 through January 2003. We analysed seasonal dependences of polarization properties of the electromagnetic noise excited by global thunderstorm activity at the Schumann resonance frequencies. The dependences were used to recover diurnal variations of the activity at three major world thunderstorm centres over different seasons. The relation between the narrow spectral line at 60 Hz which is reliably detectable at the Vernadsky Station and the radiation from electric power networks of the North-American continent is justified.