A study of self-potential method in hydrogeological exploration of volcanic area

Hydrogeological exploration examples of volcanic areas showed that there is a correlation between the range of negative self-potential (SP) anomaly and the thickness of the unsaturated zone measured in borings. Based on this correlation, SP anomaly is assumed to be created in the unsaturated medium through which meteoric water moves downward. A polarized model has been used to interpret SP anomaly. A formula of SP anomaly produced by the polarized model has been derived analytically. Because of the SP formula, a inverse technique in wavenumber domain can be used for inversion of the SP anomaly so as to calculate the location of ground water and the depth to ground water. The model test and the exploration example show that this method can be used to explore ground water in volcanic area.