National Gravity Compilation 2019: First Vertical Derivative Image of Australia

Approximately 1.8 million gravity observations, including nearly 1.4 million ground stations, were used to create this 2019 compilation. The image shows the first vertical derivative of the complete Bouguer gravity anomalies over Australia and its continental margins, derived from a grid with a cell size of approximately 435 meters. Data were compiled from the Australian National Gravity Database and supplemented with global offshore data, with ground observations collected from the 1940s to the present by government, industry, and research bodies.

Use Cases

• Model subsurface geological structures based on gravity anomaly variations.
• Identify potential mineral or hydrocarbon resources based on density contrasts revealed by the first vertical derivative.
• Integrate with other geophysical data (e.g., magnetic, seismic) for regional geological interpretation.
• Study crustal thickness and tectonic features based on the processed Bouguer anomaly grid.

Strengths

• Integrates approximately 1.8 million observations from a long temporal range (1940s to 2019).
• Station spacing varies from 11 km to less than 1 km, with major parts of the continent between 2.5 and 7 km, suggesting detailed coverage.
• Data underwent quality checks by GA geophysicists and standard processing, including terrain corrections using bathymetry and topography.

Limitations

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

Provenance

Source

Australian Ocean Data Network, incorporating data from the Australian National Gravity Database and global grids from Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

Ground and marine gravity observations processed via standard methods and FFT to create a first vertical derivative image.

Time Range

Ground data from the 1940s to present, compiled as of September 2019.

Freshness

Last updated 2026-04-10 17:58:28.492016; freshness should be verified.

Geography

Australia and its continental margins.