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
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.
