Detecting DC Electrical Resistivity Changes in Seismic Active Areas: State-of-the-Art and Future Directions

Abstract

In this paper, a critical review of the geoelectrical monitoring activities carried out in seismically active areas is presented and discussed. The electrical resistivity of rocks is one of the geophysical parameters of greatest interest in the study of possible seismic precursors, and it is strongly influenced by the presence of highly fractured zones with high permeability and fluid levels. The analysis in the present study was carried out on results obtained over the last 50 years in seismic zones in China, Japan, the USA and Russia. These past works made it possible to classify the different monitoring strategies, analyze the theoretical models for interpreting possible correlations between anomalies in resistivity signals and local seismicity, and identify the main scientific and technological gaps in the literature. In addition, great attention has been paid to some recent works on the study of the correlations between focal mechanisms and the shapes of anomalous patterns in resistivity time series. Finally, some future scenarios for the development of new activities in this field have been identified.