STUDY OF GEOPHYSICAL DISTURBANCES ON VIBROSEISMIC SOUNDING

Abstract

Using a complex equipment including a magnetic induction transducer, two transducers of the atmospheric electric field, an acoustic transducer, and a vertical seismograph, we have studied the electromagnetic and acoustic phenomena accompanying the operation of powerful seismic vibrators on the Bystrovka test ground (Novosibirsk), functioning in the sweep and monochromatic regimes in the frequency range of 5-10 Hz. An experimental proof is given for the existence of acoustic and seismic signals with close arrival times at the distances as great as 50 km from the seismic vibrator. Also, the existence of an electromagnetic wave radiated at the vibrator frequency is established. Doppler observations on the digital ionosonde "Parus" at the Kiyuchi 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 missing at night on sounding the For sporadic Es layer. The time lag between the radiated sweep signal and the similar signal in the ionosphere is estimated at 7-8 min, which agrees with the time of acoustic-signal propagation to the heights of radio-wave reflection.