Experimental examination on the heterogeneity parameter C v of earthquake precursors

Two rock samples with different structures and materials were deformed under a biaxial loading system, and multipoint strain measurements were performed for each sample. The distribution of strain anomalies during the deformation and the instability process were analyzed by using C _v value put forward by WANG Xiao-qing and CHEN Xue-zhong, et al, a parameter to describe the heterogeneous distribution of earthquake precursors, so as to examine the method of C _v value and to explore its physical meaning experimentally. The result shows that the change of C _v value is correlated to the change of deformation characteristics and is an effective parameter to describe the heterogeneity of precursor distribution. C _v value increases firstly and then decreases before the instability, and the instability occurs when C _v value decreases to the level before increasing. This indicates that C _v value may be a useful parameter for earthquake prediction. Foundation item: Chinese Joint Earthquake Sciences Foundation (9507435).