The relation of electrical Q-values and water content of rocks

摘要

It has been often discussed that dielectricity and electrical conductivity of rocks are frequency dependent. This frequency dependency suggested that the electrical Q-value is constant likewise 'constant Q model' of seismic wave. However, little attention has been paid to the electrical Q-value in the field of ground penetrating radar (GPR). In this paper, the electrical Q-values were calculated from dielectricity and electrical conductivity of igneous rocks and sedimentary rocks. It seems that the Q-values are almost constant. The present study has clarified that the electrical Q-value is inversely proportional to the square of the volumetric water content regardless of rock types. This relation is described by the mixture model of rock and water. Consequently, water content of rock mass would be estimated from the in-situ electrical Q-value. This investigation will contribute to the processing and the interpretation of GPR data, Q-value tomo-graphic inversion. Inverse Q-filtering and Q-deconvolution developed in the seismic data processing will be applicable to GPR.