Magnetic Map of the NT

Geophysical maps of the Northern Territory: NTGS produces four Territory-wide geophysical products: * Magnetic map of the Northern Territory (2004) * Radiometric map of the Northern Territory (2004) * Elevation map of the Northern Territory (2004) * Gravity map of the Northern Territory (2004).These maps represent the culmination of several decades of work since the Bureau of Mineral Resources [BMR, now Geoscience Australia (GA)] first acquired reconnaissance airborne magnetic and radiometric data in the Northern Territory at Rum Jungle in 1952. Dates of first release: Magnetic Map - 2000; Elevation Map - 2002; Radiometric Map - 2003; Gravity Map - 2004.Ninety-one percent of the area of the NT is covered by data from 53 separate NTGS and Geoscience Australia semi-detailed airborne surveys flown since 1974. These data were acquired along flight lines spaced 150-500 m apart. The remaining portion of the NT is made up of reconnaissance BMR surveys, which typically employed flight line spacings of around 1.5-3.2 km.The Magnetic and Radiometric maps make use of data from all 53 surveys, whereas the Elevation Map only includes, where available, GPS-derived height data from surveys flown since 1993. Backdrop to the Elevation Map is provided by the GEODATA 9 Second DEM, resampled to 100 m. The Gravity Map incorporates data primarily from the 11 km grid of stations collected by BMR in the 1960s and 1970s, augmented by many detailed private sector surveys (interpolated to 200 m), two 4 km datasets collected jointly by NTGS and GA in the Tanami and Tennant regions, and more recently (2003) a 2 km airborne dataset.All four maps are updated as new semi-regional surveys are acquired by NTGS and added to the public domain database. They are currently available in several forms: * Hardcopy at 1:2.5M scale. Total Magnetic Intensity, Elevation and Gravity data are rendered in pseudocolour with the intensity stretched and synthetically sun-illuminated. The three elements of Radiometric data, potassium-thorium-uranium, are assigned to red-green-blue, respectively, whereas the intensity is the total count, high-pass filtered. * Digitally, as an ER Mapper .ERS (approximately 700 Mb uncompressed) and MapInfo .TAB, on CD-ROM from the Minerals and Energy Information Centre. Grid-merging of individual datasets has been undertaken using a mesh size of 100 m. * Digitally, as an ER Mapper compressed .ECW (geolocated image) on Image Web Server.Download the: * MapInfo Tab Dataset (2.71MB) * 1:2.5M Elevation Map of the NT, (March 2004) (pdf, 6.13MB) * 1:2.5M Geological Map of the NT, (March 2004) (pdf, 5.13MB) * 1:2.5M Gravity Map of the NT, (March 2004) (pdf, 8.16MB) * 1:2.5M Magnetic Map of the NT, (March 2004) (pdf, 6.49MB) * 1:2.5M Radiometric Map of the NT, (March 2004) (pdf, 19.7MB)Other publications