Results of the International Comparison of Absolute Gravimeters in Walferdange (Luxembourg) of November 2003

Francis, Olivier; Dam, Tonie van; Amalvict, M.; Sousa, M. de Andrade; Bilker, M.; Billson, Ryan; D'Agostino, G.; Desogus, S.; Falk, Reinhard; Germak, Alessandro; Gitlein, Olga; Jonhson, D.; Klopping, F. J.; Kostelecký, Jan; Luck, B.; Mäkinen, Jaakko; McLaughlin, Daniel L.; Nunez, E.; Origlia, Claudio; Pálinkáš, Vojtech; Richard, P.; Rodriguez, Edgar M.; Ruess, D.; Schmerge, D.; Thies, S.; Timmen, Ludger; Camp, Michel Van; Westrum, Derek van; Wilmes, H.

doi:10.1007/3-540-26932-0_47

Cited by 21 publications

(19 citation statements)

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“…However, using different FG5 gravimeters can lead to gravity values with an rms error of up to 2 μGal (Robertsson et al 2001). This was confirmed by comparing 13 absolute gravimeters (including 11 FG5) in 2003 (Francis et al 2005): a standard deviation of 1.9 μGal was obtained. Consequently, Sato et al (2006) suggested to add 2 μGal in quadrature to all the formal errors and fit the data with the new error as a weight.…”

Section: Ground Gravity Measurementsmentioning

confidence: 64%

Secular gravity variation at Svalbard (Norway) from ground observations and GRACE satellite data

Mémin¹,

Rogister²,

Hinderer³

et al. 2011

Geophysical Journal International

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S U M M A R YThe Svalbard archipelago, Norway, is affected by both the present-day ice melting (PDIM) and Glacial Isostatic Adjustment (GIA) subsequent to the Last Pleistocene deglaciation. The induced deformation of the Earth is observed by using different techniques. At the Geodetic Observatory in Ny-Ålesund, precise positioning measurements have been collected since 1991, a superconducting gravimeter (SG) has been installed in 1999, and six campaigns of absolute gravity (AG) measurements were performed between 1998 and 2007. Moreover, the Gravity Recovery and Climate Experiment (GRACE) satellite mission provides the time variation of the Earth gravity field since 2002. The goal of this paper is to estimate the present rate of ice melting by combining geodetic observations of the gravity variation and uplift rate with geophysical modelling of both the GIA and Earth's response to the PDIM. We estimate the secular gravity variation by superimposing the SG series with the six AG measurements. We collect published estimates of the vertical velocity based on GPS and VLBI data. We analyse the GRACE solutions provided by three groups (CSR, GFZ, GRGS). The crux of the problem lies in the separation of the contributions from the GIA and PDIM to the Earth's deformation. To account for the GIA, we compute the response of viscoelastic Earth models having different radial structures of mantle viscosity to the deglaciation histories included in the models ICE-3G or ICE-5G. To account for the effect of PDIM, we compute the deformation of an elastic Earth model for six models of ice-melting extension and rates. Errors in the gravity variation and vertical velocity are estimated by taking into account the measurement uncertainties and the variability of the GRACE solutions and GIA and PDIM models. The ground observations agree with models that involve a current ice loss of 25 km 3 water equivalent yr −1 over Svalbard, whereas the space observations give a value in the interval [5, 18] km 3 water equivalent yr −1 . A better modelling of the PDIM, which would include the precise topography of the glaciers and altitude-dependency of ice melting, is necessary to decrease the discrepancy between the two estimates.

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Section: Ground Gravity Measurementsmentioning

confidence: 64%

Secular gravity variation at Svalbard (Norway) from ground observations and GRACE satellite data

Mémin¹,

Rogister²,

Hinderer³

et al. 2011

Geophysical Journal International

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“…The target has often been the postglacial rebound (PGR), i.e., the viscoelastic response of the Earth to past changes in ice mass (glacial isostatic adjustment GIA), or the elastic response of the Earth to present-day deglaciation. The accuracy of modern absolute gravimeters is about m 0 = 2 Gal (one-sigma) (Niebauer et al, 1995;Francis et al, 2005). Assuming independent annual measurements, a trend in gravity can be determined in N years with the precision (12/(N(N − 1)(N + 1))) 1/2 m 0 or in 10 yr to 0.22 Gal/yr.…”

Section: Introductionmentioning

confidence: 99%

Absolute gravimetry in Antarctica: Status and prospects

Mäkinen

Amalvict

Shibuya

et al. 2007

Journal of Geodynamics

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“…[6] Intercomparison campaigns have shown systematic errors (offsets) between the different absolute gravimeters that are larger than the declared uncertainties [Vitushkin et al, 2002[Vitushkin et al, , 2010Francis et al, 2005Francis et al, , 2010. Although the offsets can be determined by comparing the instruments, this is always within uncertainties and not always logistically feasible.…”

Section: The Absolute Gravimetermentioning

confidence: 99%

“…Other malfunctioning components may also bias the AG [Wziontek et al, 2008]; this is why, before and after each campaign, the instrument measured at the Membach reference station, where it was compared with the continuously measuring superconducting gravimeter [Van Camp et al, 2005; Van Camp and Francis, 2006]. Finally, the FG5#202 was regularly compared to other AG meters [Robertsson et al, 2001;Vitushkin et al, 2002Vitushkin et al, , 2010Van Camp et al, 2003;Francis et al, 2005Francis et al, , 2010Baumann et al, 2010]. The FG5#202 also benefited from maintenances by the manufacturer in 1998, 2000, 2003, 2005, 2007 and 2010, where it was also compared to other FG5s.…”

Section: The Absolute Gravimetermentioning

confidence: 99%

Repeated absolute gravity measurements for monitoring slow intraplate vertical deformation in western Europe

et al. 2011

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In continental plate interiors, ground surface movements are at the limit of the noise level and close to or below the accuracy of current geodetic techniques. Absolute gravity measurements are valuable to quantify slow vertical movements, as this instrument is drift free and, unlike GPS, independent of the terrestrial reference frame. Repeated absolute gravity (AG) measurements have been performed in Oostende (Belgian coastline) and at eight stations along a southwest‐northeast profile across the Belgian Ardennes and the Roer Valley Graben (Germany), in order to estimate the tectonic deformation in the area. The AG measurements, repeated once or twice a year, can resolve elusive gravity changes with a precision better than 3.7 nm/s2/yr (95% confidence interval) after 11 years, even in difficult conditions. After 8–15 years (depending on the station), we find that the gravity rates of change lie in the [−3.1, 8.1] nm/s2/yr interval and result from a combination of anthropogenic, climatic, tectonic, and glacial isostatic adjustment (GIA) effects. After correcting for the GIA, the inferred gravity rates and consequently, the vertical land movements, reduce to zero within the uncertainty level at all stations except Jülich (because of man‐induced subsidence) and Sohier (possibly, an artifact because of the shortness of the time series at that station).

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Results of the International Comparison of Absolute Gravimeters in Walferdange (Luxembourg) of November 2003

Cited by 21 publications

References 0 publications

Secular gravity variation at Svalbard (Norway) from ground observations and GRACE satellite data

Secular gravity variation at Svalbard (Norway) from ground observations and GRACE satellite data

Absolute gravimetry in Antarctica: Status and prospects

Repeated absolute gravity measurements for monitoring slow intraplate vertical deformation in western Europe

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