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Total Magnetic Intensity (TMI) Grid of Australia 2019 - seventh edition - 40 m cell size

Created 17/10/2025

Updated 17/10/2025

JSON format icon JSON RDF format icon RDF ISO19115-3 XML

Total magnetic intensity (TMI) data measures variations in the intensity of the Earth magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. This grid only includes airborne-derived TMI data for onshore and near-offshore continental areas. The grid has a cell size of approximately 40 m. This spatial resolution will enable 200 m line spacing surveys incorporated into the grid to be viewed at their optimum grid resolution. Since the sixth edition was released in 2015, data from 234 new surveys have been added to the database, acquired mainly by the State and Territory Geological Surveys. The new grid was derived from a re-levelling of the national magnetic grid database. The survey grids were levelled to each other, and to the Australia Wide Airborne Geophysical Survey (AWAGS), which serves as a baseline to constrain long wavelengths in the final grid. It is estimated that 33 500 000 line-kilometres of survey data were acquired to produce the 2019 grid, about 2 000 000 line-kilometres more than for the previous edition.

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Additional Info

Field Value
Title Total Magnetic Intensity (TMI) Grid of Australia 2019 - seventh edition - 40 m cell size
Language English
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/6c3d5dcc-1481-4761-8345-b9278060712a
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 20/04/2018
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
      [
        112.502532,
        -43.928981
      ],
      [
        154.662516,
        -43.928981
      ],
      [
        154.662516,
        -9.025662
      ],
      [
        112.502532,
        -9.025662
      ],
      [
        112.502532,
        -43.928981
      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Total Magnetic Intensity (TMI) Grid of Australia 2019 - seventh edition - 40 m cell size". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/total-magnetic-intensity-tmi-grid-of-australia-2019-seventh-edition-40-m-cell-size