Dual frequency observation method using the synthesized FM tuner: detections of electromagnetic waves of the Tottori-ken Seibu earthquake and the Geiyo earthquake

摘要

Electromagnetic waves related with earthquakes and volcanoes have been observed from DC to VHF bands. We are observing electromagnetic waves by using a PLL type synthesized FM tuner from 76MHz to 90MHz. In this paper, we compare the synthesized FM tuner with an analog typed FM tuner. Then, we newly propose a dual frequency observation method based on the synthesized FM tuner. Finally, we describe the observation results successfully detected co-seismic electromagnetic waves correspond to the Tottori-ken Seibu Earthquake and the Geiyo Earthquake.