基于多参数的滇东南地区跨断层异常分析

Analysis of Cross Fault Anomalies in Southeast Yunnan Based on Multi-parameters

2018年8月13,14日,云南省通海县连续发生2次5. 0级地震,打破了云南省境内504天的5级地震平静。为研究滇东南地区的强震背景,基于云南地区的跨断层短水准数据,计算了断层形变异常参数,结果显示该区域异常频次较高;详细梳理了滇东南地区多个场地的水准、基线数据,计算了断层运动年滑动速率变化、区域运动主成分信息合成、改进的断层运动协调比参数。结合震例分析认为,滇东南地区的断层运动异常幅度较大、持续时间较长,2次通海5. 0级地震震级较小,该区域仍存在发生强震的危险性。

On Aug.13 and 14,2018,two M S5.0 earthquakes successively occurred in Tonghai Country,Yunnan Province,which has broken the 504 days of M S≥5.0 seismic quiescene.In order to study the strong earthquake background in southeast Yunnan,we calculated anomaly parameters of fault deformation based on the short cross-fault level data in Yunnan,and the results showed that the anomaly frequency is high.Then,the level and baseline data of several sites in southeast Yunnan were analyzed in detail.The annual slip rate,the synthesis of regional principal component information,and the improved coordination ratio parameters of fault movement were calculated.According to the analysis of earthquake examples,the fault movement in the southeast Yunnan is larger in amplitude,longer in duration,and the magnitude of two Tonghai M S5.0 earthquakes is small,so the danger of a strong earthquake still exists in the study area.