【摘要】 中国西部钻孔应变仪观测台网始建于上世纪 80 年代末期,采用的 RZB-1 型电容式钻孔应变仪具有 10-10量级的应变灵敏度和小于 10-7/a 的飘移。9 台仪器分别安装在新疆、甘肃与四川的乌什、西昌和武都等台站,以观测因构造活动引起的地壳应变能的积累,并研究相关的地震前兆特征。总结了台网建设与观测工作,及其用于对台站附近发生的强震的监测预报结果。其中,4 种类型的震前异常应变变化较为明显:(1) 应变固体潮畸变与年周变畸变;(2) 幅度达 10-6 应变的积累,并伴随压、张性跳变;(3) 异常应变积累持续时间达数月;(4) 测得的主应力方向震前向震中方向偏转。最后,对发展我国井下观测技术提出了 3 点建议。更多还原

【Abstract】 The West China Borehole Strainmeter Networks are established in the late eighties of the twentieth century. RZB-1 borehole strainmeter with strain sensitivity of 10-10 and strain drift less than 10-7/year were adopted to detect the crustal strain energy built-up from active tectonic processes in order to study earthquake precursors. Strainmeters were installed in 9 observatories in three provinces of west China,Xinjiang,Gansu and Sichuan,and are kept on operating up to the present. This paper summarizes the observation data of strainmeters and their application to monitoring and predicting strong earthquakes occurring round the station. Four kinds of abnormal strain changes before big earthquakes are evident,that is,(1) distortion of strain tides and annual variation form,(2) strain building up of amplitude as much as 10-6 with compressive and tensive jumps,(3) duration of abnormal strain accumulation lasting few months,and (4) axis of the major principal stress turning and pointing to epicentre before the coming shock. At last,three suggestions are brought forward to help developing borehole observation and retative research in China.更多还原