The first pan-Alpine surface-gravity database, a modern compilation that crosses frontiers
- 1Earth Science Institute, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
- 2Department of Theoretical Geodesy, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinskeho 11, 810 05 Bratislava, Slovakia
- 3Department of Applied and Environmental Geophysics, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina, Ilkovicova 6, 842 48 Bratislava, Slovakia
- 4Bureau Gravimétrique International, Toulouse, France
- 5GET, University of Toulouse, CNRS, IRD, UT3, CNES, Toulouse, France
- 6Department of Mathematics and Geosciences, University of Trieste, Via Edoardo Weiss 1, 34128 Trieste, Italy
- 7Institute of Geosciences, Christian-Albrechts-University Kiel, Otto-Hahn-Platz 1, 24118 Kiel, Germany
- 8Leibniz Institute for Applied Geophysics, Stilleweg 2, 30655 Hannover, Germany
- 9Slovenian Environmental Agency, Seismology and Geology Office, Vojkova 1b, 1000 Ljubljana, Slovenia
- 10University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva 12, 1000 Ljubljana, Slovenia
- 11Institute of Earth Sciences, University of Lausanne, UNIL-Mouline Géopolis, 1015 Lausanne, Switzerland
- 12Department of Earth Sciences, Federal Institute of Technology (ETH), Sonneggstrasse 5, 8092 Zürich, Switzerland
- 13Federal Office of Topography swisstopo, Wabern, Switzerland
- 14Department of Meteorology and Geophysics, University of Vienna, 1090 Vienna, Althanstraße 14, UZA 2, Austria
- 15Institute of Geophysics, Czech Academy of Sciences, Boční II/1401, 141 31 Prague, Czech Republic
- 16Geodetic and Geophysical Institute, RCAES, Hungarian Academy of Science, Csatkai street 6-8., 9400 Sopron, Hungary
- 17Faculty of Geodesy, University of Zagreb, Kačićeva 26, 10000 Zagreb, Croatia
Abstract. The AlpArray Gravity Research Group (AAGRG), as part of the European AlpArray program, focuses on the compilation of a homogeneous surface-based gravity dataset across the Alpine area. From this data set, Bouguer- and Free Air anomalies are calculated and presented here. In 2016/17 ten European countries in the Alpine realm have agreed to contribute with gravity data for a new compilation of the Alpine gravity field in an area from 2° to 23° East and from 41° to 51° North. This compilation relies on existing national gravity databases and, for the Ligurian and the Adriatic seas, on ship-borne data of the Bureau Gravimétrique International. Furthermore, for the Ivrea zone in the Western Alps, recently acquired data were added to the database. This first pan-Alpine gravity data map is homogeneous regarding input data sets, applied methods and all corrections as well as reference frames.
Here, the AAGRG presents the data set of the recalculated gravity fields on a 4 km × 4 km grid for public release, 2 km × 2 km for special request. The final products also include calculated values for mass/bathymetry corrections of the measured gravity at each grid point, as well as height. This allows users to use later customized densities for their own calculations of mass corrections. Correction densities used are 2670 kg m−3 for landmasses, 1030 kg m−3 for water masses above and −1640 kg m−3 below the ellipsoid. The correction radius was set to the Hayford zone O2 (167 km). The new Bouguer anomaly is station completed (CBA) and compiled according to the most modern criteria and reference frames (both positioning and gravity), including atmospheric corrections. Special emphasis was put on the gravity effect of the numerous lakes in the study area, which can have an effect of up to 5 mGal for gravity stations located at shorelines with steep slopes, e.g., for the rather deep reservoirs in the Alps. The results of an error statistic based on cross validations and/or
interpolations residuals is provided for the entire database. As an example, the interpolation residuals of the Austrian data set range between about −8 and +8 mGal, the cross-validation residuals between −14 mGal and +10 mGal; standard deviations are well below 1 mGal. The accuracy of the newly compiled gravity database is close to ±5 mGal for most areas.
A first interpretation of the new map shows that the resolution of the gravity anomalies is suited for applications ranging from intra-crustal to crustal scale modelling to interdisciplinary studies on the regional and continental scales as well as applications as joint inversion with other datasets.
The data will be published with the DOI https://doi.org/10.5880/fidgeo.2020.045 (Zahorec et al., 2020) when the final paper is accepted. In the meantime, the data is accessible via this temporary review link: https://dataservices.gfz-potsdam.de/panmetaworks/review/fdc35a9f6551b01b6152ee1af7b91a5a0c3de5341d067644522c192ad7f25e7f.
Pavol Zahorec et al.
Pavol Zahorec et al.
Pavol Zahorec et al.
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