海原小山四分量钻孔应变观测相对标定和异常判定

摘要

haiyuan ningxia hill yRy - 4 field relative borehole strain meter calibration, data has obvious improvement than before calibration, data correlation significantly enhanced, borehole strain observation data to verify the hill has high credibility.Relative calibration after tidal factor to obviously improve the sensitivity, stability, synchronous change trend of significant, correlation enhancement, each element has the normal background.Contrast borehole strain curves of each element observation data, the evalution ML3.8 level and dingxi ML6.6 preceded an earthquake of magnitude of the phenomenon of twist, twist, restore, are caused by underground strain accumulation and adjustment before the earthquake showed obvious changes in the short.Smaller earthquakes release energy, curve distortion, variations in the anomalies of down, turning small, conversely change is severe, but changes in the short time basic between 10 to 15 days before the earthquake.%对宁夏海原小山yRy-4型钻孔应变仪进行实地相对标定后，数据比标定前有明显好转，资料的相关性显著增强，这验证了海原小山钻孔应变观测资料具有较高的可信度。相对标定后的潮汐因子灵敏度明显提高，稳定度明显改善，出现显著的同步变化趋势，相关性明显增强，各元件均有正常背景。对比钻孔应变各元件观测数据变化曲线，在固原ML3.8级与定西ML6.6级地震震前出现的扭曲、转折、恢复现象，是地震前地下应变积累和调整所致，表现出明显震前的短临异常变化。释放能量较小的地震，曲线扭曲、下降、转折的异常变化幅度较小，反之变化较剧烈，但短临异常变化的时间基本在震前10至15天之间。