天山中段两次地震前尼勒克分量式钻孔应变异常特征分析

ANALYSIS OF NILEKE COMPONENT BOREHOLE STRAIN ANOMALY CHARACTERISTICS BEFORE TWO EARTHQUAKES IN MIDDLE PART OF TIANSHAN MOUNTAIN

为钻孔应变短期地震预报提供新思路,通过对尼勒克分量式钻孔应变的曲线形态、自检因子、面应变和剪应变异常的梳理,发现天山中段霍城M_(S)5.0、拜城M_(S)5.4地震前尼勒克分量式钻孔应变四分量出现破年变异常。自检因子在霍城M_(S)5.0地震前2个月出现"失洽"现象,异常形态表现为先下降后回返,地震时刻的相关系数基本达到最低值或在最低值附近。地震前剪应变、面应变曲线出现分叉现象,剪应变异常变化更显著。

In order to provide new ideas for short-term earthquake prediction by borehold strain,through sorting out curve shapes,self checking factor,surface strain and shear strain anomalies of Nileke component borehole strain,it is found that NE and NW components of Nileke component borehole strain have broken annual variation anomalies before Huocheng M_(S)5.0 and Baicheng M_(S)5.4 earthquakes in Middle Tianshan Mountains.Two months before Huocheng M_(S)5.0 earthquake,the self-test factor appeared"inconsistent"phenomenon,and the abnormal shape showed that it decreased first and then returned,and the correlation coefficient at the earthquake time basically reached or appeared to the lowest value.Before the earthquakes,shear strain and surface strain curves appear bifurcation,and the variation of shear strain is often more significant.