云南地区强震活动过程中的调制比、b值

通过对云南地区1900－2000年，反映地壳介质状态的地震调制比、b值的系统研究，探讨了云南地区强震不同活动阶段的中强地震调制比、b值的活动规律，以及与云南地区强震活动规律的关系，并从地壳介质状态反应的孕震机理作出相应的剖析。结果表明中强地震的调制化、b值在强震活跃期与平静表现出有规律的变化：在强震活跃期，中强地震Rm值经过下降－上升－下降－上升过程，完成一次准周期性变化过程，结束活跃期；强震平静调制比Rm开始时高，结束时低；在活跃期与其后的平静期，b值形成一个有规律的低－高－低周期性变化；Rm、b值的最大值都出现于平静期；显示出不论是强震活跃期与平静期，中强地震的活动与强震孕育是密切相关的。

Modulating Ratio and b Value in Strong Seismicity Comse in Yunnan Region

Through systematic study on the seismic modulating ratio and b value reflecting medium state of crust in Yunnan region from 1900 to 2000,it is approached that the activity law of the modulating ratio and b value of medium-strong earthquakes in different stages of strong earthquakes and its relation to the law of the strong seismicity in Yunnan region,and analysis is made from seismogenic mechanism of crustal medium state response.The results show the following regular variation of modulating ratio and b value of medium-strong earthquakes in active and quiet stages of strong earthquakes.In active stage of strong earthquakes,going through the course of from drop to rise and from drop to rise,the Rm value of medium-strong earthquake completed quasi-periodic variation course and active stage ended.In the quiet stage of strong earthquake,Rm value was high in the initial stage and low in the last stage.In active and quiet stages,b values changed regularly from low to high and to low.Both the maximum values of Rm and b appeared in the quiet stage.It shows that activity of medium-strong earthquake closely correlated with strong earthquake preparation.