Antarctic Digital Magnetic Anomaly Project (ADMAP) Expert Group

About

The Antarctic continent plays a very important role in the plate tectonics context; the study of the lithosphere and the identification of relevant lateral discontinuities in Antarctica and surrounding areas are essential to the understanding of the geodynamic evolution of the continent.

Studies of the Antarctic continent rely extensively on magnetic anomaly data, because of the extensive ice cover. Numerous magnetic surveys have been carried out by the international community. The objective for compiling the Antarctic digital magnetic database is to enhance the geological and tectonic utility of these magnetic data. This compilation will provide an improvement in understanding the regional geology of the Antarctic, provide a regional framework for the interpretation of smaller scale areas and enable a more effective selection of areas for further investigation.

The multinational Antarctic Digital Magnetic Anomaly Project (ADMAP) was launched to compile near-surface magnetic anomaly data into a digital map and database for the Antarctic continent and surrounding oceans. The data set will be a powerful tool for determining the structure, processes and tectonic evolution of the continent, together with providing information valuable in the reconstruction of the Gondwanaland and Rodinia supercontinents. The resulting merged potential field anomaly maps connect geological mapping studies of the various programmes in terms of parameters such as:

  • major structure and composition of the continent. The magnetic data provide 2-dimensional regional maps of structural grain in basement; suture zones between basement terranes; the basement terranes themselves; the nature of intra continental rifts and the extent of major faults;
  • geological timing and kinematics associated with the evolution of the continent. Relative ages and displacements can be derived from the detailed geophysical mapping of rock units. The distinctive magnetic signatures of some plutons, serpentinites, amphibolites, migmatites, young sedimentary basins and volcanic rocks provide important markers for extracting both the orientation of regional faulting and relative timing;
  • paleoenvironment and global change; from the reconstruction of Gondwana, it might be possible to identify the locations of old oceans and therefore infer circulation paths that would have affected past climates;
  • essential information on the crustal contribution to the Earth's magnetic field from a remote and poorly understood region. This effort will permit improved global geomagnetic field modelling and assist with verification and calibration of magnetometer observations obtained from polar orbiting satellite missions. The integration of satellite and near-surface magnetic anomalies will result in a compilation that accurately portrays the fullest possible spectrum of magnetic anomalies for the Antarctic lithosphere.

For more information about ADMAP, please visit the ADMAP website.