IAGA Resolutions on magnetic anomaly maps for a global scale 

Resolution No.16 (1977): National magnetic anomaly maps with common scale and projection

IAGA, considering the interest of global magnetic anomalies, urges Member Countries to produce national magnetic anomaly maps to lead to the ultimate production of an international magnetic anomaly map using, for comparison, the same scale and the same projection as those of the world geological map.

Resolution No.16 (1979): Compilation of magnetic anomaly map

IAGA, considering the interest in global magnetic anomalies and that a certain number of countries have already completed maps on a scale of 1:2 500 000, urges the compilation of such maps within the next four years as a contribution to a global magnetic anomaly map. 

Resolution No. 4 (1995): Digital magnetic anomaly map and database

IAGA, considering the rapid progress currently being made in retrieving and compiling existing low-level airborne and marine magnetic anomaly data over large continental and oceanic areas, and noting the importance of magnetic anomaly data for geological and tectonic mapping of the Earth's crust, urges the compilation and publication of a digital magnetic anomaly map and database of the entire world (land and sea). 

Resolution No. 3 (1997): Magnetic anomaly data

IAGA, considering the importance of magnetic anomaly mapping for global geological and tectonic interpretation, and noting the existence of numerous sets of low-level airborne and marine magnetic anomaly data and the rapid progress being made in retaining and compiling existing data, regrets that many data sets remain classified or confidential, even after they have outlived the original purpose of acquisition, and urges the custodians of such data sets to release them (or non-sensitive versions of them) into the public domain as soon as possible.

Source of resolution text: Catalogue of IAGA resolutions.