Australian Gravity Anomaly Grid With Tilt Filter

A gravity anomaly grid derived from approximately 1.8 million ground and marine gravity observations across Australia. The grid has a cell size of 0.00417 degrees (approximately 435m) and was compiled by Geoscience Australia using data from government, industry, and research sources collected from the 1940s onward. The final 2019 compilation integrates terrestrial data from the Australian National Gravity Database with offshore data from the Scripps Institution of Oceanography.

Use Cases

• Map subsurface geological structures by interpreting the tilt-filtered gravity anomaly values across the grid.
• Correlate gravity anomaly patterns with known mineral deposits to identify prospective regions for exploration.
• Model crustal thickness and density variations using the spherical cap Bouguer anomaly values as a base layer.
• Assess data coverage and station density, which varies from 11 km to less than 1 km spacing, for survey planning.

Strengths

• Integrates nearly 1.4 million gravity stations from a national database spanning decades of collection.
• Grid cell resolution of 0.00417 degrees provides consistent continental-scale coverage.
• Data processing includes terrain corrections using bathymetry and topography, and application of a tilt filter.

Limitations

• Station spacing is irregular, ranging from 11 km to under 1 km, creating variable resolution.
• The underlying observations have inconsistent collection methods and instruments over the 80-year time range.
• Offshore data is sourced from a global model (v28.1) which may have lower resolution than the terrestrial data.

Provenance

Source

Geoscience Australia via the Australian Ocean Data Network.

Collection Method

Compiled from ground and marine gravity measurements, processed with terrain corrections and a tilt filter applied to a spherical cap Bouguer anomaly grid.

Time Range

Observations collected from the 1940s to 2019.

Freshness

Based on data current as of September 2019, though metadata was updated in April 2026.

Geography

Australia and its continental margins.