SEGJ Technical Conference

A development of the measurement system for electrical conductivity values using radio waves

Abstract The new system has been developed for prospecting of conductivity anomalies in shallow subsurface layers. This system with the simple electric circuits detects the phase difference between the horizontal and vertical magnetic components of AM radio waves in the frequency range of 500k to1600kHz, because phase parameters are relatively easy to measure. For an evaluation study of this system, a field survey was conducted on the test-field of Shirasu banks in Kagoshima Prefecture. The relatively large phase values were observed in the area where the surface layers are highly saturated with water. The 2D resistivity models indicate that these values are caused by the roughly 10 ohm-m layer at 1.5 m depth.