National Gravity Compilation 2019: Free Air Anomaly Grid for Australia

Nearly 1.8 million gravity observations, including 1.4 million ground stations and over 450,000 line kilometers of airborne data, underpin this 2019 national grid. The dataset integrates ground, airborne, and offshore measurements to model subsurface rock density variations across Australia and its continental margins. Processed by Geoscience Australia, it reveals geological structures for resource exploration and geophysical research.

Use Cases

• Mineral and resource exploration targeting based on subsurface density anomalies.
• Geological mapping and structural interpretation of the Australian continent.
• Integrating ground and airborne gravity data to improve resolution in poorly sampled areas.
• Studying crustal architecture and tectonic history from free air gravity anomalies.
• Calibrating regional geophysical models with a nationally consistent gravity compilation.

Strengths

• Integrates a large volume of observations: approximately 1.8 million gravity points, including 1.4 million ground stations.
• Combines multiple data sources for improved coverage: ground, airborne gravity (345,000 line km), airborne gravity gradiometry (106,000 line km), and global offshore data.
• Data collection spans a long time period, with measurements acquired from the 1940s to the present day.
• Processed and quality-checked by Geoscience Australia (GA) geophysicists to be fit-for-purpose.

Limitations

• Specific column names and data schema are not provided in the available metadata.
• The exact data format (e.g., grid cell size, coordinate reference system) is not detailed in the descriptions.
• Metadata for size, row count, license, and author is listed as 'None' or 'unknown' across sources.

Provenance

Source

Geoscience Australia (GA), Commonwealth/State/Territory Governments, mining industry, universities, and research organisations. Offshore data from Scripps Institution of Oceanography/NOAA/NGA.

Collection Method

Gravity observations processed via standard methods to isolate the subsurface rock response. Grid derived from the Australian National Gravity Database (as of September 2019) and supplemental airborne and global datasets.

Time Range

1940s to 2019

Freshness

2026-06-27 17:13:59.218001

Geography

Australia and its continental margins