Stochastic relation between the line-of-sight VHF propagation and earthquakes

This paper was intended to find out any relation between anomalous line-of-sight propagation on VHF radio band and occurrences of earthquakes near the radio propagation path. For that purpose, we established a multidirectional VHF band monitoring system and monitored the waves continuously over the long time. After stochastic consideration of fluctuation in the monitored waves, it was found out that the anomalies on the propagation were monitored on the VHF band a few days prior to occurrences of earthquakes which were characterized by magnitude of them and distance from epicenters. Moreover, the anomaly appeared on multidirectional propagation paths simultaneously.