Feasibility study applied to mapping tidal effects in the Pannonian basin--An effort to check location dependencies atμGal level
Feasibility study applied to mapping tidal effects in the Pannonian basin——An effort to check location dependencies at μGal level作者机构:Geodetic and Geophysical InstituteResearch Centre for Astronomy and Earth SciencesHungarian Academy of Sciences.9400 SopronHungary Geological and Geophysical Institute of Hungary1145 BudapestHungary University of ViennaDepartment of Meteorology and Geophysics1090 WienAustria Zentralanstalt fur Meteorologie and Geodynamik1190 ViennaAustria University of MiskolcDepartment of Geophysics3515 Miskolc-EgyetemvarosHungary
出 版 物:《Geodesy and Geodynamics》 (大地测量与地球动力学(英文版))
年 卷 期:2018年第9卷第3期
页 面:237-245页
基 金:the financial support of NKFIH-OTKA in the framework of contract K101603
主 题:Gravity tide mapping Spring gravity meters Instrumental tests Co-located observations Location dependence of delta factors
摘 要:This paper summarizes the main instrumental and methodological points of the tidal research which was performed in the framework of the National Scientific Research Fund Project K101603. Since the project is still running the tidal analysis results published here are only preliminary. Unmodelled tidal effects have been highlighted in some recent absolute gravity measurements carried out in the Pannonian basin resulting in a periodic modulation exceeding the typical standard deviations (±1microGal) of the drop sets. Since the most dominant source of the daily gravity variation is the bulk tidal effect, the goal of the project is to check its location dependency at BGal level. Unfortunately Hungary has had no dedicated instrumentation, so an effort was made to make the available LaCoste- Romberg spring G meters capable for continuous recording. As a reference instrument the GWR SG025 operated in the Conrad Observatory, Austria was also used and in the mean time of the project, a Scintrex CG-5 became also available, Eventually 6 instruments at 5 different locations were operated for 3 9 months mainly in co-located configuration. Although many experiments (moving mass calibrations) were done to determine the scale factors and scale functions of the instruments, the direct comparison of the tidal parameters obtained from the observations is still questionable. Therefore the ratio of the delta factors of O1 and M2 tidal constituents was investigated supposing that M2 is much more influenced by the ocean loading effect than O1. The slight detected increase of δ(O1 )/δ(M2) (≈0.2%) toward east does not contradict to theory. This result has to be validated in the near future by analyzing available ocean loading models.