Study of geophysical disturbances on vibroseismic sounding

Using a complex equipment including a magnetic induction transducer, two tr ansducers of the atmospheric electric field, an acoustic transducer, and a vertical seismograph, we have studied the electromagnetic and acoustic phen omena accompanying the operation of powerful seismic vibrators on the Bystr ovka test ground (Novosibirsk), functioning in the sweep and monochromatic regimes in the frequency range of 5-10 Hz. An experimental proof is given f or the existence of acoustic and seismic signals with close arrival times a t the distances as great as 50 km from the seismic vibrator. Also, the exis tence of an electromagnetic wave radiated at the vibrator frequency is esta blished. Doppler observations on the digital ionosonde "Parus" at the Klyuc hi station permitted registration of the ionosphere disturbances during the operation of a seismic 100-tons vibrator. The effect was detected only in the day time, by the wave reflection from the stable E layer, and was missi ng at night on sounding the F or sporadic Es layer. The time lag between th e radiated sweep signal and the similar signal in the ionosphere is estimat ed at 7-8 min, which agrees with the time of acoustic-signal propagation to the heights of radio-wave reflection.