WGM2012 global model

WGM2012 global model

General

WGM2012 is the first release of a high resolution grids and maps of the Earth’s gravity anomalies (Bouguer, isostatic and surface free-air), computed at global scale in spherical geometry. It has been realized by the Bureau Gravimétrique International (BGI) in the frame of collaborations with international organizations such as Commission for the Geological Map of the World (CGMW), UNESCO, International Association of Geodesy (IAG), International Union of Geodesy and Geophysics (IUGG), International Union of Geological Sciences (IUGS) and with various scientific institutions.

WGM2012 gravity anomalies are derived from the available Earth global gravity models EGM2008 and DTU10 and include 1’x1′ resolution terrain corrections derived from ETOPO1 model that consider the contribution of most surface masses (atmosphere, land, oceans, inland seas, lakes, ice caps and ice shelves). These products have been computed by means of a spherical harmonic approach using theoretical developments carried out to achieve accurate computations at global scale (Balmino, G., Vales, N., Bonvalot, S. and Briais, A., 2011. Spherical harmonic modeling to ultra-high degree of Bouguer and isostatic anomalies. Journal of Geodesy. DOI 10.1007/s00190-011-0533-4).

Reference / Authors

Bonvalot, S., Balmino, G., Briais, A., M. Kuhn, Peyrefitte, A., Vales N., Biancale, R., Gabalda, G., Reinquin, F., Sarrailh, M., 2012. World Gravity Map. Commission for the Geological Map of the World. Eds. BGI-CGMW-CNES-IRD, Paris

WGM2012 reference theoretical paper (Journal of Geodesy)

WGM2012 reference explanatory leaflet

WGM2012 maps (1:50 000 000)

Disclaimer : WGM2012 digital products are provided for academic purposes. No warranty is given on the accuracy of the data and models. By using these products, users acknowledge that BGI is not responsible for any consequence of  the use of the data or models.

Download global grids (2’x2′ resolution)

1. Complete spherical Bouguer gravity anomaly

2. Complete spherical Isostatic gravity anomaly (Airy-Heiskanen, Tc=30 km)

3. Free-air gravity anomaly on the Earth’s surface (Molodenski)

4. ETOPO1 topography

Data extract tool

Click here to select a given area
(note that extraction is limited here to 100°x100°)

This page allows you to view and download 2’x2′ regional grids derived from the WGM2012 global model

  • Complete spherical Bouguer anomaly
  • Complete spherical Isostatic anomaly (Airy-Heiskanen, Tc=30km)
  • Surface free-air anomaly (Molodenski)
  • ETOPO1-derived gravity disturbances of surfaces masses
  • ETOPO1 topography

Examples

BGI_WGM2012_Africa_Bouguer_reduced
BGI_WGM2012_Africa_Isostatic_reduced
BGI_WGM2012_Africa_Freeair_reduced

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