A study on feature and mechanism of the tidal geoelectrical field
潮汐地电场特征及机理研究

Based on the analysis of data from 100 geoelectrical field observatories in China continent, the tidal geoelectrical field can be divided into the TGF-A of approximate sine waves and the TGF-B of approximate trapezoidal waves. TGF-A was produced basically by large water area nearby, it is not only closely related to solid tide, but also closely related to the acreage and distance of the nearby water area, lithology structures and geotectonic movement, and so on. TGF-B is closely related to the S_q current produced by air tide, and also to the degree of saturation and permeability of the rock, and so on. The reason for TGF-A waveform distortion may be alteration of cranny water periodic transfusion in the rock due to stress change, and the abrupt change of TGF-B background value may be caused by ground fluid transfusion into rock area with increased cracks. These two mechanisms could be the theoretical foundation for application of tidal geoelectrical field data in short-term and impeding strong earthquake prediction.