National Gravity Compilation 2019 DGIR 0.5VD Image: Australian Subsurface Structure

A geospatial grid representing the half vertical derivative of de-trended global isostatic residual gravity anomalies over Australia and its continental margins. The image is derived from nearly 1.4 million ground gravity stations and marine data, compiled from observations dating from the 1940s to 2019. It was produced by Geoscience Australia from the 2019 Australian National Gravity Grids A series.

Use Cases

• Map subsurface density variations based on processed gravity anomaly data.
• Interpret geological structure for mineral exploration using the derived isostatic residual grid.
• Model continental crustal thickness and composition based on gravity-derived features.
• Integrate gravity data with other geophysical datasets for regional geological analysis.

Strengths

• Integrates nearly 1.4 million gravity stations from a national database.
• Data quality is checked by GA geophysicists to be fit-for-purpose.
• Grid has a spatial resolution of approximately 435 meters (0.00417 degrees).
• Combines ground observations from the 1940s onward with offshore global gravity data.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

Australian National Gravity Database (ANGD) and global gravity grids from Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

Processed from ground and marine gravity observations using standard geophysical methods and a fast Fourier transform (FFT).

Time Range

1940s to 2019 (ground observations), with offshore data from v28.1 of the Global Gravity grid.

Freshness

Last updated 2026-06-23 06:01:36.287408; freshness should be verified.

Geography

Australia and its continental margins.