华北地区ML4级地震平静的分析

结合华北地区MS≥6级地震活动的韵律特征进行了地震幕的划分,并统计分析了华北地区（33°~43°N,108°~125°E）1980年以来出现ML4级地震平静与中等地震的对应情况,主要结论如下：（1）华北地区目前处于第五地震活跃幕的相对平静时段,目前6级地震已经平静16年多,随时可能进入新的地震活动幕;（2）ML4级地震平静对中强地震的前兆意义与当前地震活动所处地震幕的不同阶段有关,在1980—2000年ML4级地震平静与M5级及以上地震有较好的对应关系;2000年之后ML4级地震平静与ML5.2级及以上地震对应关系较好;（3）2013年11月23日山东莱州ML5.0级地震打破华北地区ML4级地震平静189天,虽然在预报期限内没有ML5.2级以上地震,但是2014年4月1日发生黄海ML5.1级地震,鉴于目前震群活跃,仍要警惕华北地区出现更大地震的危险。

The Analysis of ML4 Earthquake Quiescence in North China

This paper analyzed the corresponding relationship between quiescence of ML4 earthquake and medium shocks since 1980 in North China Area （33°~43°N, 108°~125°E）, and discussed the differentiate of seismic seismic episode in the area according to Ms≥6 earthquake activity. The main conclusions are as follows： （1） The North China area is in a seismic quiescence period after the fifth seismic episode and Ms≥ 6 earthquake has not occurred for more than 16 years, and it will enter to a new seismic episode for some time to come. （2）The Corresponding relationship between quiescence and earthquake is very different at different time of the earthquake scene. From 1980 to 2000, there is a better corresponding relationship between ML4 earthquake and M5 earthquake; After 2000, the relationship is appropriate between ML4 earthquake and ML5. 2 earthquake. （3）Shandong Laizhou ML5. 0 earthquake broke the quiescence of ML4 earthquakes in 189 days, although there is a MLS. 1 earthquake occurred at yellow sea, it may be in risk of earthquakes of MI 5.2 or above in the future in North China area.