Plumb line deflection varied with time obtained by repeated gravimetry

IntroductionPlumb line deflection (PLD) express the incline between the geoid and the surface of ellipsoidal earth, i.e., the deflection of the real plumb line of calculating point to the normal direction of the corresponding point in the ellipsoidal surface. It varied in the range of about 3(~5( generally, and the largest value will be 20(~30( in spatial domain. Plumb line is closely related to spatial distribution of gravity field on the earth surface. PLV of a point on the earth surface c…

Plumb line deflection varied with time obtained by repeated gravimetry

In this paper, the plumb line deflection varied with time (PLV) are calculated with the Vening-Meinesz formula for Xiaguan and Beijing point based on the 28 and 39 campaigns of gravimetry at the local gravity networks in the Western Yunnan Earthquake Prediction Experiment Area and the North China, respectively. Based on the results, we conclude that: (1) the maximum of PLV is under 0.1″ and amplitudes of interannual variation are under 0.02″. (2) PLV can be determined with the reliability of 0.01″ by the modeling based on the precession of repeated gravimetry. This implies that repeated gravimetry could be used to determine the PLV. (3) There exist some common and different characteristics for the different places and different components. It may provide a new approach for the study on the local or global geodynamic by using repeated gravimetry. Foundation item: State Natural Foundation (19373018) and the State Science and Technology Target Project (96-913-04-01-03).