Amplitude Variations of VLF Signal of NWC Transmitter (19.8 khz) Propagating Over the Earthquake Epicentre

Lower ionosphere perturbations accompanying earthquakes can be investigated by VLF signals of radio stations. Amplitude variations of VLF signal of NWC transmitter (19.8 kHz) are considered during registration in Yakutsk from August 21 to September 15, 2018 to detect lower ionosphere disturbances as a result of the earthquake (magnitude is 6.6, depth is 35 km) on Hokkaido Island (42.686 ° N 141.929 ° E) on September 5, 2018. On the day of the earthquake the effect manifested as the amplitude increase of the radio signal.