Observed secular gravity trend at Onsala station with the FG5 gravimeter from Hannover

authored by: L. Timmen, A. Engfeldt, H. G. Scherneck
Abstract: Annual absolute gravity measurements with a FG5 instrument were performed in Onsala Space Observatory by the Institute of Geodesy of the Leibniz Universität Hannover from 2003 to 2011 and have been continued with the upgraded meter FG5X in 2014. Lantmäteriet, Gävle, with their FG5 absolute gravimeter have visited Onsala since 2007. Because small systematic errors may be inherent in each absolute gravimeter, their measuring level and a resulting bias (offset) between the instruments must be controlled over time by means of inter-comparison. From 2007 to 2014, 8 direct comparisons took place well distributed over the time span. A complete re-processing of the absolute gravity observations with the Hannover instrument has been conducted to improve the reduction of unwanted gravity effects. A new tidal model is based on continuous time series recorded with the GWR superconducting gravimeter at Onsala since 2009. The loading effect of the Kattegat is described with a varying sea bottom pressure (water and air mass load) and has been validated with the continuous gravity measurements. For the land uplift,which is a result of the still ongoing glacial isostatic adjustment in Fennoscandia, a secular gravity trend of -0.22 μGal/yr was obtained with a standard deviation of 0.17 μGal/yr. That indicates a slight uplift but is still not significantly different from zero.
Organisation(s): Institute of Geodesy
External Organisation(s): Lantmäteriet - The Swedish Mapping, Cadastral, and Land Registration Authority
Chalmers University of Technology
Type: Article
Journal: Journal of Geodetic Science
Volume: 5
Pages: 18-25
No. of pages: 8
Publication date: 09.04.2015
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Earth and Planetary Sciences (miscellaneous), Geophysics, Computers in Earth Sciences, Applied Mathematics, Astronomy and Astrophysics
Electronic version(s): https://doi.org/10.1515/jogs-2015-0001 (Access: Open)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{11e5a5f923e34caf975863e566947d08,
title = "Observed secular gravity trend at Onsala station with the FG5 gravimeter from Hannover",
abstract = "Annual absolute gravity measurements with a FG5 instrument were performed in Onsala Space Observatory by the Institute of Geodesy of the Leibniz Universit{\"a}t Hannover from 2003 to 2011 and have been continued with the upgraded meter FG5X in 2014. Lantm{\"a}teriet, G{\"a}vle, with their FG5 absolute gravimeter have visited Onsala since 2007. Because small systematic errors may be inherent in each absolute gravimeter, their measuring level and a resulting bias (offset) between the instruments must be controlled over time by means of inter-comparison. From 2007 to 2014, 8 direct comparisons took place well distributed over the time span. A complete re-processing of the absolute gravity observations with the Hannover instrument has been conducted to improve the reduction of unwanted gravity effects. A new tidal model is based on continuous time series recorded with the GWR superconducting gravimeter at Onsala since 2009. The loading effect of the Kattegat is described with a varying sea bottom pressure (water and air mass load) and has been validated with the continuous gravity measurements. For the land uplift,which is a result of the still ongoing glacial isostatic adjustment in Fennoscandia, a secular gravity trend of -0.22 μGal/yr was obtained with a standard deviation of 0.17 μGal/yr. That indicates a slight uplift but is still not significantly different from zero.",
keywords = "Absolute gravimetry, Fennoscandian land uplift, Gravimeter comparisons, Gravity variations, Onsala Space Observatory, Superconducting gravimeter, Absolutgravimetrie, Fennoskandische Landhebung, Gravimetervergleiche, Gravitationsvariationen, Onsala Space Observatory, Superconducting gravimeter",
author = "L. Timmen and A. Engfeldt and Scherneck, {H. G.}",
note = "Publisher Copyright: {\textcopyright} 2015 L. Timmen et al.",
year = "2015",
month = apr,
day = "9",
doi = "10.1515/jogs-2015-0001",
language = "English",
volume = "5",
pages = "18--25",
journal = "Journal of Geodetic Science",
issn = "2081-9943",
publisher = "De Gruyter Open Ltd.",
number = "1",
}