Study on the Relation Between the Suddenly Changed Sequence of Earth Resistivity and Earthquakes

摘要

Based on fracture mechanics, a large amount of practically observed data are analyzed in this paper, and it is disclosed that the earth resistivity stations around the epicenter of a strong event have shown seismically an anomalous earth resistivity suddenly changed sequence. The maximum sudden change in the sequence tends to shift backward with the increase of epicentral distance, while it shifts forward with the increase of the magnitude of the earthquake. Also, the maximum sudden change expands from the epicenter to the peripheral areas. The result of study has shown that the obviousness degree of the anomalies is related to the measuring direction. The lithological contrast around the stations also influences the time of the anomaly occurrence. The maximum sudden change of the sequence will be advanced while the rock resistance to pressure is not good. On the basis of these findings, the authors propose that it might be possible to predict the three key elements of forthcoming earthquakes by using the suddenly changed sequence, frequency of the sudden change, the expansion velocity of the maximum sudden change, and the time-distance product.