2014年云南景谷6.6级地震前地震活动异常特征研究

摘要

2014年10月7日云南景谷发生6.6级地震，此次地震前，滇西南地区存在长达7.3年的6级地震平静异常和2536天5级地震平静异常。与5级地震、6级地震平静不同的是，思普地区4级地震异常活跃。景谷地震发生在由4级地震形成的背景空区、3级地震形成的孕震空区内。2014年10月7日5时36分发生的3.5级地震打破3级地震围空，属于逼近地震。研究表明，景谷地震前的地震活动呈现长期、中期、短临特征。%The JingguM 6.6 earthquake occurred on October 7, 2014 in Yunnan Province. Before the earthquake, there are the quiet ofM≥6.0 earthquakes for up to 7.3 years and the quiet of M≥6.0 earthquakes for up to 2 536 days in Southwest Yunnan. But there are different that theM4.0—4.9 earthquakes increased notably since 2013 in Sipu area. Jinggu earthquake occurred in the background gaps formed byM4.0—4.9 earthquakes, there is the preparatory gaps formed byM3.0—4.9 earthquakes in short time too. AnM 3.5 earthquake occurred at 05:36 on October 7,2014. It occurred on the edges of preparatory gaps. We called it “imminent earthquakes”. The research shows that the seismicity indicates the dynamic characteristics of long,medium and short term seismic anomalies before this earthquake.