Excitation of global artificial Pc1 signals during FENICS-2024 experiment: 1. Observations

In July–August 2024 on the Kola Peninsula, the FENICS-2024 experiment was conducted to generate artificial electromagnetic signals at night, using two power transmission lines as a horizontal radiating antenna. The generator frequency varied discretely from session to session from 1 to 194 Hz with current amplitude from ~150 A at low frequencies to ~40 A at high frequencies. The paper presents the results of the first stage of the experiment when the power transmission line Vykhodnoy—Olenegorsk with a distance between earth electrodes of substances L=84 km was utilized as a radiating antenna. Magnetic stations, located from ~1200 to ~2100 km from the nodal substation, recorded signals with frequencies from 1 to 9 Hz with ~0.3–~6.0 fT/A amplitudes normalized to the emitter current. The observations have shown the promise of the new type of active experiments on creating a probing signal for magnetotelluric sounding over a large area. The observation results will be compared with theoretical models in the subsequent work.