云南宁蒗2次中强震前地震活动异常共性特征

Common characteristics of seismicity anomalies before two earthquakes in Yunnan,Ninglang

在云南中强震频发的宁蒗—盐源地区,2012年、2022年分别发生M_(S)5.7、M_(S)5.5地震,2次地震震中相距较近且震级相当,对2次地震前地震活动异常共性特征进行分析总结。研究表明,宁蒗—盐源地区M_(S)≥5.0地震平静异常,滇西北M_(L)≥4.0地震平静,小滇西发生中强地震,M_(L)≥3.0地震丛集活动和震中附近M_(L)≥3.0地震平静。

In Ninglang-Yanyuan region in Yunnan Province,where moderate-strong earthquakes occur frequently,Ninglang M 5.7 and M 5.5 earthquakes occurred in 2012 and 2022,respectively.The epicenters of two earthquakes are close to each other and the magnitudes are similar.The common characteristics of seismicity anomalies before these two earthquakes are analyzed and summarized as follows:Before these two earthquakes,the M_(S)≥5.0 earthquakes were abnormally quiet in Ninglang-Yanyuan region,the M_(L)≥4.0 earthquakes were quiet in northwest Yunnan,moderatestrong earthquakes occurred in western Yunnan,M_(L)≥3.0 earthquakes clustered,and M_(L)≥3.0 earthquakes were quiet near the epicenters.