National Gravity Compilation 2019: Free Air Anomaly Grid for Australia

A 2019 compilation of nearly 1.4 million gravity stations from the Australian National Gravity Database, supplemented with offshore data. The grid shows free air anomalies over Australia and its continental margins with a cell size of approximately 435 meters. Data was acquired by government, industry, and research organizations from the 1940s to 2019 and processed by Geoscience Australia.

Use Cases

• Model subsurface density variations based on free air gravity anomalies.
• Interpret geological structure for resource exploration based on gravity data.
• Integrate with other geophysical datasets for continental-scale geological studies.

Strengths

• Derived from nearly 1.4 million ground gravity observations from a national database.
• Station spacing varies from 11 km to less than 1 km, with major parts of the continent between 2.5 and 7 km.
• Grid cell size is 0.00417 degrees (approximately 435m), providing fine spatial detail.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

Geoscience Australia (GA), Australian National Gravity Database, supplemented with global data from Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

Ground observations processed via standard methods and quality-checked by GA geophysicists, gridded with offshore data.

Time Range

1940s to September 2019.

Freshness

Last updated 2026-04-16 08:36:08.073471; freshness should be verified.

Geography

Australia and its continental margins.