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National Gravity Compilation 2019 (free air grid)

Created 17/10/2025

Updated 17/10/2025

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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This National Gravity Compilation 2019 (free air grid) is a free air anomaly grid for the 2019 Australian National Gravity Grids A series. This gravity survey was acquired under the project No. 202008. This gravity anomaly grid is derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented with offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD were used to generate this grid. The ground gravity data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. Station spacing varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. The grid shows free air anomalies over Australia and its continental margins with a cell size of 0.00417 degrees (approximately 435m). The data are given in units of um/s^2, also known as 'gravity units', or gu.

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Additional Info

Field Value
Title National Gravity Compilation 2019 (free air grid)
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/8c5ca598-af03-46e1-a917-d8d10f6aa8dc
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 19/06/2019 - 01/10/1947
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
      [
        107.9979,
        -48.0021
      ],
      [
        164.0021,
        -48.0021
      ],
      [
        164.0021,
        -7.9979
      ],
      [
        107.9979,
        -7.9979
      ],
      [
        107.9979,
        -48.0021
      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "National Gravity Compilation 2019 (free air grid)". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/national-gravity-compilation-2019-free-air-grid