云南地区中强地震连发及其调制比的时空展布特征

剖析并定义了云南地区1970～2001年中强地震连发，发现中强地震连发的时空展布具有空间分布按一定方向有规律迁移，时间分布集中于5～11个月的特点。利用小震调制比分析云南地区中强地震连发的孕震演变，结果发现小震调制比的异常特性：空间上中强震连发前2～0．5a的时段内小震调制比出现8个平方度以上的异常面积元，异常面积元集中的地区为未来中强震连发的主体区域，时间上中强震连发前1～3a出现小震调制比R。的高值异常。并用花岗岩块体受压实验结果初步探讨了中强地震连发及其调制比时空展布特征的构造活动。

The Spatial-temporal Characteristics of Continuous Occurrence of Mid-strong Earthquakes and Its Modulation Ratio in Yunnan Area

The continuous occurrence of Mid-strong earthquakes in Yunnan from 1970 to 2001 has been anatomized and defined. It is found that the spatial-temporal contribution of continuous occurrence of Mid-strong earthquakes has following properties: spatial distribution migrates regularly in certain direction, and temporal distribution concentrates on 5-11 months. The seismogenic evolution of continuous occurrence of Mid-strong earthquakes has been analyzed by using modulation ratio of small earthquakes in Yunnan. It is discovered that the modulation ratio has anomalous characteristics as follows: 2-0.5 years before the continuous occurrence of strong earthquakes, the modulation ratio appears more than 8 square degree anomalous area units and the anomalous areas indicate the principal area of the occurring strong earthquakes. The high value of modulation ratio appears 1-3 years before the continuous occurrence of strong earthquakes. The pressure test on granite has researched into the tectonic activities between the continuous occurrence of strong earthquakes and its spatial-temporal characteristics of modulation ratio.