THE CORRELATION OF TECTONIC STRESS FIELD AND FAULT SLIP RATE WITH STRONG EARTHQUAKES IN NORTHCHINA

Since 70 B. C., 77 earthquakes with M ≥ 6.0 have been recorded in North China. Thirty-three of them occurred on active fault zones or were closely related to active faults. According to some principles, eighteen of them are selected as samples and the univariate and bivariate linear regression analysis is made by least-square approximation for them. The results of the two regression analyses are compared and are shown as follows:1. The significance level of F test on the bivariate regression analysis is as high as that on the univariate analysis. 2. The correlation coefficient of the bivariate analysis is larger than that of the univariate analysis. 3. The residual standard deviation of the bivariate analysis,σ, is less than that of the univariate analysis. We may draw the conclusion as follows:1. The earthquake magnitude is not only related to the fault slip-rate, but also to the stress direction. 2. The earthquakes with M ≤ 3.5 is not correlative with whether the fault is active or not. 3. In the bent place of a fault, it is easy that a large earthquake may occur. 4. A slip-rate and a stress direction are two important factors to determine earthquake magnitude 5. The effect of a multivariate regression analysis is superior to that of a univariate analysis.