2011年腾冲M_(S)5.2地震前近场地球物理异常分析  

Analysis of near-field geophysical anomalies before the 2011 Tengchong M_(S)5.2 earthquake

作　　者：马学智 李宗兴 MA Xuezhi;LI Zongxing(Tengchong City Earthquake Prevention and Disaster Reduction Bureau,Yunnan Province 679100,China)

机构地区：[1]腾冲市防震减灾局,中国云南679100

出　　处：《地震地磁观测与研究》2024年第2期34-43,共10页Seismological and Geomagnetic Observation and Research

摘　　要：2011年6月20日和8月9日,云南腾冲地区先后发生M_(S)5.2地震,构成腾冲M_(S)5.2双震。2次腾冲M_(S)5.2地震前,地震地球物理异常集中分布在震中100 km范围的近场区,对2次地震近场区内水位、形变(水平摆观测)、水氡、水温、流量等地球物理观测资料进行综合分析,分析发现:①大部分异常持续时间在3个月以上,部分异常始于2010年初,显著中期异常测项为腾冲滇19井水位和腾冲水平摆倾斜观测;②2次地震发震前2个月,龙陵邦腊掌水氡测项出现高值异常;③临震阶段,6月20日腾冲M_(S)5.2地震前,腾冲荷花塘、热海大滚锅出现明显宏观异常,震后异常强度和频率明显增强,对8月9日腾冲M_(S)5.2地震有明显指示意义。值得注意的是,在震中85 km范围内,2011年3月10日发生盈江M_(S)5.8地震,2次腾冲地震的中期异常成为此次盈江地震“共同的地震地球物理异常”,且震后部分异常持续,并出现新的异常,表现出异常时空演化过程与地震活动迁移相匹配的特征。On June 20 and August 9,2011,the Tengchong area in Yunnan Province experienced two M_(S)5.2 earthquakes,forming the Tengchong M_(S)5.2 double earthquakes.Before the two Tengchong M_(S)5.2 earthquakes,geophysical anomalies were concentrated in the near-field area within 100 km of the epicenter.A comprehensive analysis of geophysical observation data such as water level,deformation(horizontal pendulum observation),water radon,water temperature,and flow in the near-field area of the two earthquakes revealed that:①most anomalies lasted for more than 3 months,and some began in early 2010.The significant mid-term anomaly measurement items were the water level of the Dian 19 well and the horizontal pendulum tilt observation in Tengchong;②Two months before the two earthquakes,there was a high-value anomaly in the water radon measurement item at Longling Bangla Zhang;③During the pre-earthquake stage,before the Tengchong M_(S)5.2 earthquake on June 20,there were obvious macroscopic anomalies in the Tengchong Hehuatang and Rehai Dagunguo.The intensity and frequency of the anomalies significantly increased after the earthquake,which has a clear indicative significance for the Tengchong M_(S)5.2 earthquake on August 9.It is worth noting that within a range of 85 km from the epicenter,the Yingjiang M_(S)5.8 earthquake occurred on March 10,2011.The mid-term anomalies of the two Tengchong earthquakes became the“common geophysical anomaly”of this Yingjiang earthquake,and some anomalies persisted after the earthquake,with new anomalies appearing,showing characteristics that match the abnormal spatiotemporal evolution process with seismic activity migration.

关 键 词：腾冲M_(S)5.2地震 地球物理观测资料 短临异常 宏观异常 

分 类 号：P31[天文地球—固体地球物理学]