通过分析2001年10月~2015年5月兰州钻孔倾斜观测资料的变化趋势，发现由于仪器安装时未安装底座托盘而造成观测资料存在长期的趋势性漂移。利用抛物线函数对兰州钻孔倾斜观测资料进行趋势拟合后发现，临潭-宕昌断裂3次中强地震发生前兰州钻孔倾斜观测资料的拟合残差存在着一定的异常变化，因此认为兰州钻孔倾斜观测有可能较好地反映临潭-宕昌断裂的中强地震活动。

By analyzing the changing trends of borehole tilt observation data from October 2001 to May 2015 in Lanzhou,we found that due to the base tray being not installed,there is a trend of drift for long term observation data. After using parabolic function for fitting tendency of the borehole tilt observation data of Lanzhou,we found that the fitting residual error of the borehole tilt observation data in Lanzhou has certain abnormal variations before the three strong earthquakes in the Lintan-Tanchang fracture. We believe that the borehole tilt observation data in Lanzhou can well monitor the moderate earthquake activities in the Lintan-Tanchang fracture,and can provide the basis for earthquake prediction of the Lintan-Tanchang fault zone in the future.

P315

中国地震局监测司一般专项（2015125）资助