1:15,000,000 – 105cm x 82cm
This set of three anomaly maps that compose the World Gravity Map (Bouguer, Isostatic and Free Air) is the result of an iterative gravity mapping project undertaken under the aegis of the Commission for the Geological Map of the World (CGMW).
World Gravity Map (WGM) denotes a set of 3 global anomaly maps of the Earth’s gravity field realized by the Bureau Gravimétrique International (BGI), a service of the International Association of Geodesy (IAG). These new products, realized for the Commission for the Geological Map of the World (CGMW), UNESCO, International Union of Geodesy and Geophysics (IUGG) and International Union of Geological Sciences (IUGS), represent the first gravity anomaly maps computed in spherical geometry, that take into account a realistic Earth model.
The gravity anomaly maps presented here (Bouguer, Isostatic and Surface Free-Air) are derived from available Earth gravity models (EGM2008, DTU10), and include high resolution terrain corrections that consider the contribution of most surface masses (atmosphere, land, oceans, inland seas, lakes, ice caps and ice shelves). New theoretical developments have been performed to achieve accurate computations at global scale, using spherical harmonic approach (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).
Such gravity anomaly, which point out the density heterogeneities in the Earth’s interior (crust, mantle…), are used in a large variety of applications: geophysics, structural geology, geodesy (shape of the Earth, geoid), exploration of natural resources (oil or mining prospecting), etc. Soon available in a digital form, these maps will be regularly updated and distributed for research and educational purposes.
This project, led by Bureau Gravimétrique International (BGI), has benefited from the collaboration of various research in