National Gravity Compilation 2019: First Vertical Derivative Grid of Australia

Geoscience Australia's National Gravity Compilation 2019 DGIR 1VD image is a processed gravity anomaly grid covering Australia and its continental margins. The grid is derived from nearly 1.4 million ground stations in the Australian National Gravity Database and offshore data, with observations collected from the 1940s to September 2019. It represents the first vertical derivative of de-trended global isostatic residual anomalies, calculated via a fast Fourier transform process.

Use Cases

• Map subsurface geological structures based on gravity anomaly data.
• Support mineral and resource exploration by identifying density contrasts in the crust.
• Integrate with other geophysical datasets for regional geological modeling.
• Calibrate or validate geophysical models using a nationally consistent gravity grid.

Strengths

• Derived from a substantial base of nearly 1.4 million gravity station observations.
• Data quality is checked by Geoscience Australia geophysicists to be fit-for-purpose.
• Incorporates data from multiple sources including Commonwealth, State, industry, and universities from the 1940s onward.
• Has a defined spatial resolution with a grid cell size of approximately 435 meters.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Ground station spacing varies from 11 km to less than 1 km, leading to non-uniform data density across the continent.

Provenance

Source

Australian Ocean Data Network, aggregating data from Geoscience Australia, government bodies, industry, and research organizations.

Collection Method

Ground and marine gravity observations processed via standard methods, with a first vertical derivative calculated via FFT.

Time Range

Observations from the 1940s to September 2019.

Freshness

Last updated 2026-06-23 03:06:51.900599; freshness should be verified.

Geography

Australia and its continental margins.