Abstract:Based on "the idea that commensurallity means the extension of periodicity," we have made different statistics in different regions for the strong earthquakes, Ms≥6.0, in South Xinjiang. It has been found that the commensurability of strong earthquake activities exists nearly in every region, and in most eases the results are satisfactory, only with a few exceptions in which errors are large. We have also found that the effect is clear from a point of view of the statistics, and that the relative error, which is free from the prediction period, is a normal distribution by means of assumed test. And. the most important thing is that there is a period of about eleven years as a least common multiple for the different commensurable values in each region, which appears to be a better characteristic of the commensurability.
In spite of some false reports, we still think it practical for the trend estimation of strong earthquake time the to make use of commensurability. In fact, good results were obtained in middle period prediction for the Xikeer earthquake of magnitude 5.7 on Dec.19, 1977, and the Kuche's, 6.0, on March. 29, 1979.
