摘要
Based on the geoelectric observation data of the 1976 Tangshan earthquake of M=7. 8 compiled by the Research Group on the Geoelectricity of the Tangshan Great Earthquake, a dimensionless factor S has been defined as the degree of ground resistivity anisotropy. The S values during the generation process of that earthquake have been calculated and their variations have been analyzed. The result has showed that the variation of the degree of ground resistivity anisotropy existed throughout the process of generation and occurrence of the Tangshan earthquake and the features of its pattern are representative. The S value can therefore be taken as a new precursory factor of earthquakes which can be applied together with other dimensionless factors in the analysis and prediction of earthquakes. A physical explanation of the variation of the S value has also been given.
Based on the geoelectric observation data of the 1976 Tangshan earthquake of M=7. 8 compiled by the Research Group on the Geoelectricity of the Tangshan Great Earthquake, a dimensionless factor S has been defined as the degree of ground resistivity anisotropy. The S values during the generation process of that earthquake have been calculated and their variations have been analyzed. The result has showed that the variation of the degree of ground resistivity anisotropy existed throughout the process of generation and occurrence of the Tangshan earthquake and the features of its pattern are representative. The S value can therefore be taken as a new precursory factor of earthquakes which can be applied together with other dimensionless factors in the analysis and prediction of earthquakes. A physical explanation of the variation of the S value has also been given.