Australian National Gravity Grids: Free Air and Bouguer Anomalies

Data from the 1940s to 2019 underpins this series of gravity grids covering Australia and offshore regions. The grids combine over 1.4 million ground observations from the Australian National Gravity Database with airborne surveys and a global offshore model, achieving a 400-meter cell size. This 2019 release includes updated versions of specific grids to correct artefacts found in earlier iterations.

Use Cases

• Mineral exploration targeting based on gravity anomaly patterns.
• Geological mapping and structural interpretation using the Complete Bouguer Anomaly grid.
• Basin architecture analysis leveraging the integration of onshore and offshore data.
• Geophysical research utilizing the high-resolution (400 m) De-trended Global Isostatic Residual grid.

Strengths

• Integrates a large volume of data, including nearly 1.4 million ground gravity observations.
• Provides improved spatial resolution with a 400-meter cell size, enhanced from previous 800-meter grids.
• Combines onshore, airborne, and global offshore data sources for continental-scale context.

Limitations

• Some grids (A7 and B7) contained artefacts requiring a version update, indicating initial data quality issues.
• Metadata for specific column names, row counts, and license information is not provided.
• The exact temporal endpoint for data collection is ambiguous, described as 'to the present day' but based on a 2019 database snapshot.

Provenance

Source

Geoscience Australia, Australian Ocean Data Network, Commonwealth/State/Territory Governments, industry, universities.

Collection Method

Combination of ground station, airborne gradiometry, and global satellite-derived gravity data.

Time Range

1940s to 2019

Freshness

Last updated on data.gov.au: 2026-06-27.

Geography

Australia and surrounding offshore regions