贵阳地震监测中心站钻孔应变观测长期变化分析

Long Term Variation Analysis of Borehole Strain Observation at Guiyang Seimic Monitoring Central Station

分析贵阳地震监测中心站钻孔应变2008—2018年观测资料,发现其观测记录曲线具有年变趋势平稳,相对变化较小的特点,与贵阳及周边区域地震活动水平相对较低的构造背景相对应。研究期内贵州省内共发生3次M4.7以上地震,震前钻孔应变分析曲线均出现不同程度尖峰、转折等异常现象,虽然异常幅度不是十分显著,仍可作为该区地震短临跟踪、震后趋势判定以及贵州省发展地震形变观测工作的参考依据。

Analyzing the observation data of the borehole strain of Guiyang Central Station from 2008 to 2018,it is found that the observation record curve has a stable annual trend and a small relative change,which corresponds to the relatively low level of seismic activity in Guiyang and the surrounding area.During the study period,there were 3 earthquakes above M4.7 occurred in Guizhou Province.Before the earth⁃quakes,all these borehole strain analysis curves showed abnormal phenomena such as spikes and transi⁃tions of varying degrees.Although the abnormal amplitude is not very significant,it can still be used as a reference basis for earthquake imminent tracking and post-earthquake trend determination in this area.