Geophysical research: article

V.N. Koneshov 1,2 D.V. Abramov 2 N.V. Drobyshev 2 D.A. Malysheva 1
1 Vladimir State University named after Alexander and Nikolay Stoletov 2 Schmidt Institute of Physics of the Earth, Russian Academy of Sciences
Journal: Geophysical research
Tome: 24
Number: 2
Year: 2023
Pages: 84-91
UDK: 550.831.23:550.312
DOI: 10.21455/gr2023.2-5
Full text
Keywords: CG-5 Autograv gravimeter, offset of gravimeter zero-point, non-linear component of gravimeter zero-point.
Аnnotation: The operation of the CG-5 Autograv type gravimeters in different climatic zones from the tropics to the far north makes it necessary to evaluate the influence of various meteorological parameters on the obtained measurements. One of the most important parameters characterizing the accuracy of the results obtained by a relative gravimeter is the position, as well as the change in the zero point. The experimental results of long-term observations at the gravimetric station confirmed the need to take into account the change in the drift velocity of the gravimeter zero-point. It has been established that the accel- eration of the gravimeter zero-point drift is due, among other things, to a change in the humidity of the environ- ment, that occurs despite the sealing of the sensitive element. In order to reveal the dependence of the zero-point drift velocity of the CG-5 Autograv gravimeter on humidity, a series of field experiments was carried out. Their idea is to place gravimeters for a certain period of time in extreme conditions, corresponding to 100 % humidity in a limited space (specialized box). At the same time, the external temperature and atmospheric pressure remained the same as outside the box. The duration of the active phase of direct influence of 100 % humidity on the gravimeter varied from 2 to 7 weeks for different experiments. At the same time, both before and after, the gravimeter was at rest in order to obtain the clearest transient process caused only by a change in humidity. The obtained data were processed separately, but all the main conclusions are similar to each other. As a result, it was found that humidity significantly affects the gravimeter zero-point drift, and its increase leads to acceleration of the gravimeter zero-point drift. The results are confirmed by the entire series of experiments, but for better information, this article considers one of the longest performed experiments.
Bibliography: Abramov D.V., Drobyshev N.V., Malysheva D.A., Estimation of the ambient temperature influence on long- term high-precision measurements with the CG-5 Autograv gravimeter, Geofizicheskie issledovanija (Geophysical Research), 2022, vol. 23, no. 1, pp. 20-29. [In Russian].

Abramov D.V., Koneshov V.N., Chebrov V.N., Improvements of long time observation technique by relative gravimeter CG-5 methodic, Seismicheskie pribory (Seismic Instruments), 2016, vol. 52, no. 3, pp. 20-26. [In Russian].

Boulanger Y.D., Gusev N.A., Lokhov V.V., Slivin Y.A., Heifets M.E., Scheglov S.N., Determination of gravita- tional acceleration at Moscow (Ledovo), Murmansk, Odessa and Nakhodka, Bureau gravimetrique inter- national, Bulletin d'information, 1974, no. 34, pp. 1.25-1.30.

Drobyshev M.N., Study of changes in angular position of gravimetric pedestal with a system of geophysical in- struments, Seismicheskie pribory (Seismic Instruments), 2014, vol. 50, no. 2, pp. 70-76. [In Russian].

Elsaka B., Comparison of Different Polynomial Degrees for Correcting the Instrumental Drift of Scintrex CG-5 Autograv Gravimeter, Australian Journal of Basic and Applied Sciences, 2020, vol. 14, no. 5, pp. 19-25. DOI: 10.22587/ajbas.2020.14.5.3

El Wahabi A., Dittfeld H.J., Simon Z., Meteorological influence on tidal gravimeter drift, Bulletin d'Information des Marées Terrestres, 2000, vol. 133, pp. 10403-10414.

Krivitsky G.E., Andreev O.P., Kobylkin D.N., Akhmedsafin S.K., Kirsanov S.A., Bezmaternykh E.F., Gravimet- richeskij kontrol' razrabotki gazovyh i gazokondensatnyh mestorozhdenij (Gravimetric control of devel- opment of gas and gas condensate fields), Moskow, Nedra Publishing House LLC, 2012, 374 p. [In Russian].

Laurent P.J., Approximation et optimisation, Paris, Editions Hermann, 1972, 531 p.

Otnositel'nyi gravimetr CG-5. Sistema Scintrex Autograv: Rukovodstvo po ekspluatatsii. red. 4 (Relative gra- vimeter CG-5. Scintrex Autograv System: Operation Manual. ed. 4), Ontario, Scintrex, 2008, 156 p. [In Russian].

Professional wireless Internet weather station meteoscan 937PRO. Operation Manual, Oberegg, RST Group, 2017, 68 p.