Study on the Criterion of the Correlation between Deformation Precursors and Earthquakes

The relationship between pre-seismic anomalous changes and earthquakes is one of the most basic information to comprehend the process of earthquake preparation and conduct earthquake prediction research. However, few researchers have carried out relevant investigations for a long time. In this paper, the distribution characteristics of deformation anomalies before the Wenchuan earthquake are analyzed, and the widespread distribution area is discussed. Based on previous studies, we improve the relationship between anomaly duration t and magnitude M by introducing distance D. The new model is characterized by lower magnitude fitting error, making it possible to establish the correlation between deformation precursors and earthquakes. The correlation standard between precursors and earthquakes here is defined as Niu's criterion, which is applied to analyze and interpret the relationship between the short-term anomalies of Hongliuxia fault leveling and the Wenchuan and Jiuzhaigou earthquakes.