Points representing magnetic anomalies in nanoTesla (nT). The altitude is 5 km above the WGS84 ellipsoid, except for the marine data and model (indexes 11 and 44) where altitude is the sea level (0). Magnetic anomalies ('magnetic_anomaly') are computed with reference to geomagnetic field model CM4 for year 1990. During the processing, ('index') is removed from the original data grid and replaced by ('long_wavelength') to obtain ('magnetic_anomaly'). The original magnetic anomaly data grid can therefore be restored by adding ('index') and removing ('long_wavelength') from ('magnetic_anomaly'). === Original Data Source === World Digital Magnetic Anomaly Map The WDMAM (World Digital Magnetic Anomaly Map) is an international scientific project under the auspices of IAGA (International Association of Geomagnetism and Aeronomy) and CGMW (Commission for the Geological Map of the World), aiming to compile and make available magnetic anomalies caused by the Earth lithosphere, on continental and oceanic areas, in a comprehensive way, all over the World. The project started in 2003 and resulted in a first version of the map (Korhonen et al., 2007). A call for candidates initiated in 2010 led to the building of a new map which, after evaluation and correction, was released at the IUGG General Assembly of Prag in June 2015 as WDMAM version 2.0. This web site aims to distribute freely and as widely as possible a provisional version of the map (in jpeg format), the full grid (in ASCII format) or parts of the grid (in ASCII or GMT grd formats) to interested scientists and the general public. A printed version of the map will be released by CGMW in a very near future. A paper describing the building of the map will be published soon (Lesur et al., 2016, in press). Citation: Dyment, J., Lesur, V., Hamoudi, M., Choi, Y., Thebault, E., Catalan, M., the WDMAM Task Force*, the WDMAM Evaluators**, and the WDMAM Data Providers**, World Digital Magnetic Anomaly Map version 2.0, map available at http://www.wdmam.org. Citation URL: http://www.wdmam.org