2013年甘肃岷县漳县M_S6.6地震跨断层形变异常研究  

Research on Cross-fault Deformation Abnormity of Minxian-Zhangxian M_S6. 6 Earthquake in Gansu in 2013

作　　者：杨晓东[1] 李宁[1] 刘立炜[1] 张四新[1] 

机构地区：[1]中国地震局第二监测中心,陕西西安710054

出　　处：《地震研究》2014年第4期578-587,669,共10页Journal of Seismological Research

基　　金：中国地震局2014年度震情跟踪专项工作任务(2014010206);陕西省科学技术研究发展计划项目(2014KJXX-18)联合资助

摘　　要：通过对2013甘肃岷县漳县交界发生MS6.6强震的发震构造区在地震前后跨断层形变研究发现：四店、麻界滩和毛羽沟场在震前出现形变异常,3个场地临震单期形变是往期平均值的2-7倍;3个场地震前形变异常持续时间不超过4个月,震后4个月除毛羽沟场地外其余场地基本恢复到往期平均水平;四店场地临震形变△V（5.5 mm）约是麻界滩和毛羽沟的2倍,产生这种形变差异的原因可能是由于岷县地震主要动力来源是西秦岭北缘断裂的活动产生,因此主断裂上的形变异常大于分支断裂;临潭—宕昌断裂具有差异性活动特征,断裂中东段活动性强于西段,岷县漳县地震的复发周期约为（220±40）a,震级为6-6.6级。An Ms6. 6 earthquake occurred at the boundary between Minxian and Zhangxian Counties on Jul. 22, 2013. Studying the cross fault deformation of seismogenic structure area before and after the Minxian-Zhangxian Ms6. 6 earthquake, we found that the deformation anomaly appeared in Sidian, Majietan and Maoyugou sites before the earthquake. The deformation in single period were 2 - 7 times than the average value, and the duration of deformation anomaly was less than 4 months before the earthquake in these three sites. The deformation recovered to average value in 4 months after the earthquake except for Maoyugou site. The impending deformation AV in Sidian site （5.5mm） was about 2 times than that in Majietan and Maoyugou sites, which were due to the main dynamic source was from the activity of North margin of Western Qinlin Fault, so the deformation anomaly in main fault was larger than that of branch fault. The characteristic of Lintan-Tanchang Fault is the diversity of activity, and the activity of the eastern section of active faults is stronger than that in the western part. The recurrence period of Minxian-Zhangxian earthquake is about （220 ± 40） a, the magnitude of it is from 6.0 to 6. 6.

关 键 词：岷县漳县MS6.6地震 跨断层水准 累积形变 单期形变 震前异常 

分 类 号：P315.72[天文地球—地震学]