Variations of impulsive natural VLF signals passing over epicenters of earthquakes by observations in Yakutsk

For distant monitoring of disturbances in the lower ionosphere signals of low-frequency radio stations are often used. In particular, the method is used for investigation of ionospheric responses (disturbances) caused by seismic activity. As a variant of this method for the detection of seismic disturbances in the ionosphere one can use natural radio signals - an electromagnetic radiation of thunderstorm discharges (atmospherics). The examples of the effects of three earthquakes in the variations of average amplitude of atmospherics received in Yakutsk (φ = 62.1° N, λ = 129.7° E) were considered. The increase of signal amplitude for some days before the events can be considered as a precursor. It allows to used observations of impulse electromagnetic thunderstorm signals as one of possible means of distant monitoring of strong earthquakes.