Abstract
Tidal gravity changes arise from the response of the solid Earth to the tidal forces of the Sun, Moon and planets close to the Earth, and are a comprehensive reflection of the structure and distribution of physical properties of the Earth’s interior. As a result, observations of tidal gravity changes are the basis of studies on other global and/or regional dynamic processes. The characteristics of tidal gravity changes in the region of the Tibetan Plateau were investigated through continuous gravity measurements recorded with a superconducting gravimeter (SG) installed in Lhasa over a year. Through contrast measurements with a spring gravimeter LaCoste-Romberg ET20 at the same site, the gravity observations in Lhasa were scaled to the international tidal gravity reference in Wuhan. Meanwhile, the scale factor of the SG was determined accurately as −777.358 ± 0.136 nm s−2 V−1, which is about 2.2% less than the value provided by the manufacturer. The results indicate that the precision of the tidal gravity observations made with the SG in Lhasa was very high. The standard deviation was 0.459 nm s−2, and the uncertainties of for the four main tidal waves (i.e. O1, K1, M2 and S2) were better than 0.006%. In addition, the observations of the diurnal gravity tides had an obvious pattern of nearly diurnal resonance. As a result, it is affirmed that the Lhasa station can provide a local tidal gravity reference for gravity measurements on the Tibetan Plateau and its surrounding regions. The loading effects of oceanic tides on tidal gravity observations in Lhasa are so weak that the resulting perturbations in the gravimetric factors are less than 0.6%. However, the loading effects of the local atmosphere on either the tidal or nontidal gravity observations are significant, although no seasonal variations were found. After removal of the atmospheric effects, the standard deviation of the SG observations in Lhasa decreased obviously from 2.009 to 0.459 nm s−2. Having removed the loading effects of oceanic tides and local atmosphere, it was found that the tidal gravity observations made with the SG in Lhasa significantly differed by about 1% from those expected theoretically, which may be related to active tectonic movement and the extremely thick crust in the region of the Tibetan Plateau. A more-certain conclusion requires longer accumulation of SG data and further associated theoretical studies.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Doodson A T. The harmonic development of the tide generating potential. Proc Roy Soc Lond Ser A, 1954, 31: 37–61
Cartwright D E, Tayler R J. New computations of the tide generating potential. Geophys J R Astro Soc, 1971, 23: 45–74
Xi Q W. The algebraic deduction of the harmonic development for the tide generating potential with the IBMPC. In: Proceedings of the 10th international symposium on the Earth tides, Madrid, 1985. 481–489
Tamura Y. A harmonic development of the tidal generating potential. Bull Inf Marées Terres, 1987, 99: 6813–6815
Hartmann T, Wenzel H G. the HW95 tidal generating potential catalogue. Geophys Res Lett, 1995, 22: 3553–3556
Roosbeek F A. A harmonic development of the tide generating potential. Geophys J Int, 1996, 126: 197–204
Wahr J M. Body tides on an elliptical, rotating, elastic and oceanless earth. Geophys J R Astr Soc, 1981, 64: 677–703
Dehant V, Defraigne P, Wahr J. Tides for a convective Earth. J Geophys Res, 1999, 104: 1035–1058
Mathews P M. Love numbers and gravimetric factor for diurnal tides. J Geod Soc Jpn, 2001, 46: 231–236
Xu J Q, Sun H P. Deformation response of a SNREI Earth to surface loads and tidal forces (in Chinese). Chin J Geophys, 2003, 46: 328–343
Melchior P. A new data bank for tidal gravity measurements (DB92). Phys Earth Planet Inter, 1994, 82: 125–155
Melchior P, Ducarme B, Francis O. The response of the Earth to tidal body forces described by second- and third-degree spherical harmonics as derived from a 12 year series of measurement with the superconducting gravimeter GWR/T3 in Brussels. Phys Earth Planet Inter, 1996, 93: 223–238
Ducarme B, Venedikov A, Arnosob J, et al. Determination of the long period tidal waves in the GGP superconducting gravity data. J Geodyn, 2004, 38: 307–324
Xu J Q, Sun H P, Ducarme B. A global experimental model for gravity tides of the Earth. J Geodyn, 2004, 38: 291–304
Xu H Z, et al. Geodetic Studies on Tibetan Plateau (in Chinese). Wuhan: Hubei Science and Technology Press, 2001. 3–67
Mao H Q, Xu H Z, Song X L, et al. East-west gravity tidal profile of China (in Chinese). Chin J Geophys, 1989, 32: 62–69
Hinderer J, Crossley D. Scientific achievements from the first phase (1997–2003) of the Global Geodynamics Project using a worldwide network of superconducting gravimeters. J Geodyn, 2004, 38: 237–262
Zerbini S, Richter B, Negusini M, et al. Height and gravity variations by continuous GPS, gravity and environmental parameter observations in the southern Po Plain, near Bologna, Italy. Earth Planet Sci Lett, 2001, 192: 267–279
Richter B, Zerbini S, Matonti F, et al. Long-term crustal deformation monitored by gravity and space techniques at Medicina, Italy and Wettzell, Germany. J Geodyn, 2004, 38: 281–292
Xu J Q, Zhou J C, Luo S C, et al. Study on characteristics of long-term gravity changrs at Wuhan station. Chin Sci Bull, 2008, 53: 2033–2040
Sun H P, Xu J Q, Li Q. Detail spectral structure of Earth’s gravity field and its application (in Chinese). Prog Geophys, 2006, 21: 345–352
Xu H Z, Sun H P, Xu J Q, et al. International tidal gravity reference values at Wuhan station. Sci China Ser D-Earth Sci, 2000, 43: 77–83
Vauterin P. Tsoft: Graphical & interactive software for the analysis of Earth tide data. In: Ducarme B, Paquet P, eds. Proceedings of the 13th International Symposium on the Earth Tides, Brussels, 1998. 481–486
Wenzel H G. The nanogal software: data processing package ETERNA 3.3. Bull Inf Marées Terrestres, 1996, 124: 9425–9439
Farrell W E. Deformation of the Earth by surface loads. Rev Geophys Space Phys, 1972, 10: 761–797
Xu H Z, Mao W J. Correction models for ocean loading tides in Chinese continent (in Chinese). Sci China Ser B, 1988, 9: 984–994
Agnew D. A program for computing ocean-tide loading. J Geophys Res, 1997, 102: 5109–5110
Schwiderski E W. Ocean Tides I, Global ocean tidal equations. Marine Geod, 1980, 3: 161–217
Egbert G, Bennett A, Foreman M. TOPEX/Poseidon tides estimated using a global inverse model. J Geophys Res, 1994, 99: 24821–24852
Le Provost C, Genco M, Lyard F, et al. Spectroscopy of the ocean tides from a finite element hydrodynamic model. J Geophys Res, 1994, 99: 24777–24797
Andersen O B. Global ocean tides from ERS-1 and TOPEX/ POSEIDON altimetry. J Geophys Res, 1995, 100: 25259–25429
Matsumoto K, Takanezawa T, Ooe M. Ocean tide models developed by assimilating TOPEX/POSEIDON altimeter data into hydrodynamical model: A global model and a regional model around Japan. J Oceanogr, 2000, 56: 567–581
Lefèvre F, Lyard F, Le Provost C, et al. FES99: A global tide finite element solution assimilating tide gauge and altimetric information. J Atmos Ocean Technol, 2002, 19: 1345–1356
Zhou J C, Xu J Q, Sun H P. Accurate correction models for tidal gravity in Chinese continent (in Chinese). Chin J Geophys, 2009, 52: 1474–1482
Merriam J B. Atmospheric pressure and gravity. Geophys J Int, 1992, 109: 488–500
Sun H P. Atmospheric gravity Green’s function. Chin Sci Bull, 1997, 42: 1712–1719
Boy J P, Gegout P, Hinderer J. Reduction of surface gravity data from global atmospheric pressure loading. Geophys J Int, 2002, 149, 534–545
Luo S C, Sun H P, Xu J Q. Theoretical computation of the barometric pressure effects on deformation, gravity and tilt (in Chinese). Chin J Geophys, 2005, 48: 1288–1294
Kroner C, Jentzsch G. Comparison of different barometric pressure reductions for gravity data and resulting consequences. Phys Earth Planet Inter, 1999, 115: 205–2187
Xu J Q, Sun H P, Zhou J C. Experimental detection of the inner core translational triplet. Chin Sci Bull, 2010, 55: 276–283
Xu J Q, Sun H P, Luo S C. Study of the Earth’s free core nutation by tidal gravity data recorded with international superconducting gravimeters. Sci China Ser D-Earth Sci, 2002, 45: 337–347
Author information
Authors and Affiliations
Corresponding author
Additional information
This article is published with open access at Springerlink.com
Rights and permissions
This article is published under an open access license. Please check the 'Copyright Information' section either on this page or in the PDF for details of this license and what re-use is permitted. If your intended use exceeds what is permitted by the license or if you are unable to locate the licence and re-use information, please contact the Rights and Permissions team.
About this article
Cite this article
Xu, J., Chen, X., Zhou, J. et al. Characteristics of tidal gravity changes in Lhasa, Tibet, China. Chin. Sci. Bull. 57, 2586–2594 (2012). https://doi.org/10.1007/s11434-012-5130-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11434-012-5130-2