Wei Jin 1,2,3) ;Liu Gaochuan 4) ; Li Hui 1,2) ; Shen Chongyang 1,2) ; and Yao Yao 1,2)
1)School of Geodesy and Geomatics,Wuhan University, Wuhan 430079;2)Key Laboratory of Earthquake Geodesy,Institute of Seismology, CEA, Wuhan 430071;3)Wuhan Base of Institute of Crustal Dynamics,CEA,Wuhan 430071;4)China Earthquake Networks Center,Beijing 100045
摘要 利用姑咱地震台超过3年半的连续重力观测资料、降雨数据、地下水位资料和全球陆地水模型观测资料，采用多项式拟合和相关分析研究弹簧重力仪非线性漂移特征与外界因素干扰的关系。结果表明：姑咱地震台DZW型重力仪长期连续重力观测的漂移具有明显的线性特征（约1 200×10 -8 ms -2 /a），并且在人员进洞调整仪器时还会产生非线性漂移。在考虑固体潮、气压潮和极潮的影响后，利用多项式分段进行非线性漂移改正，重力残差变化量级为±（10~15）×10 -8 ms -2，而且3年间4次雨季都同步有明显的重力正异常变化相对应。研究不仅揭示了弹簧重力仪的非线性漂移与外界影响因素的关系，同时也为改正漂移与排除水负荷对重力的干扰提供了新的分析和处理方法。
Abstract：More than 3 years gravity data recorded at Guza seismostation using DZW gravimeter are analyzed along with ground water, precipitation and two global continental water storage models (GLDAS, CPC). It is shown that the linear drift of the instrument is about 1 200×10 -8 ms -2 /a stablely. Furthermore, after artificial disturbance (such as power interrupt, restart, lightning), the instrument drift is inconsistent with the previous, so called nonlinear drift that is different from linear drift. Corrected with polynomial fitting method considering the barth tide, air pressure and polar tides, the gravity residual is ±(10-15)×10 -8 ms -2 and shows 4 gravity anomalous variations synchronous with the precipitation for 3 years.So, this research indicates that the drift rule of spring gravity for long time and supply a new method for correcting drift and obstaining gravity variations affected by water loading.
