The composite magnetic anomaly map of the East Antarctic

Abstract Airborne and marine magnetic observations in East Antarctica and adjacent seas of the Indian Ocean were compiled for a magnetic anomaly map of the Antarctic. For East Antarctica, over 260,000 line km of Russian reconnaissance magnetic data were used that had been collected since 1955 mainly at line spacings of about 5, 20 and 50 km. For the offshore areas, magnetic data from American, Australian, German, Japanese, and Russian marine expeditions were incorporated. Digitally recorded data and data digitized from published and unpublished maps and profiles were included in the compilation. Local grids of these data were developed and merged into a regional grid at an interval of 5 km. The prime product of this compilation is a shaded-relief map that shows the most complete and coherent perspective to date of the region's magnetic character. In combination with other types of data, the compilation provides new insight on the tectonic features and history of this largely inaccessible region of the world. It maps out approximately 4300 km of the Antarctic Continental Margin Magnetic Anomaly (ACMMA) related to Gondwana breakup, new cratons and mobile belts, and large submarine igneous provinces.