2017年8月9日精河M_S6.6地震前钻孔应变异常特征分析

Borehole strain anomaly characteristics analysis before the Jinghe M_S6.6 earthquake on August 9,2017

利用形态分析法对天山中段钻孔应变资料进行分析,认为2017年8月9日新疆精河M_S6.6地震前天山中段钻孔应变出现明显的短期异常及临震异常。研究结果表明,精河地震发生前,天山中段9套钻孔应变资料中有5套出现异常现象,其中,2项短期异常,3项临震异常;异常特征主要表现为压缩-拉张变化、压缩速率变快、高频抖动信息、规律性脉冲及周期性台阶变化等;钻孔应变异常中,如果多套钻孔应变资料在同一时间段均出现异常,要重点关注极大应变方向重合区域;此次震前异常出现的时间顺序在空间上与天山中段断裂走向基本一致。

We use the morphological analysis method to analysis borehole strains＇ data in midrange of the Tianshan Mountains. The results indicate that there are 5 borehole strains with anomalies in the total 9 borehole strains before this earthquake,which include 2 short-term anomalies and 3 impending anomalies. The anomaly characteristics are of tensin-compress feature,faster compression rate,high frequency information and regular pulse and periodic steps. If two or several borehole strains had anomalies at the same time,we should then pay more attention to the overlap area of maximum strain direction.