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Australia magnetic anomaly pixel map
This map is an attractive representation of the relief of Australia with north-west illumination. The elevation image was derived from Geoscience Australia`s GEODATA 9 Second Digital Elevation Model (DEM) with a grid spacing of 9 seconds of latitude and longitude (approximately 250 metres on the ground). Over 5 million spot height values were used in the generation of the DEM.
This edition of the Magnetic anomaly map of Australia results from a completely new compilation of Total Magnetic Intensity (TMI) grid data. It has been produced using a new method of matching the individual survey grids and the use of independent data to help constrain long wavelengths. 680 individual grids have been matched and merged into the composite used to produce this image, with the resolution of each grid optimal for the specifications of the source survey line data. Since the Third Edition (Milligan and Tarlowski, 1999), data from many new surveys have been added, acquired mainly by the State and Territory geological surveys. It is estimated that 19 million line-kilometres of survey data were acquired to produce the grid data, 10 million line-kilometres more than for the Third Edition. This data is used to study the tectonic structure of Australia by mapping variations in the earth's magnetic field. The 'hotter colours' (eg red) show areas of stronger magnetic field and the 'cooler colours' (eg dark blue) show areas of weaker magnetic field. Magnetic data used to produce the Magnetic Anomaly Map of Australia are available for free download via the Geophysical Archive Data Delivery System.