Australian Gravity Anomaly Grid With Airborne Data

Over 1.8 million gravity observations, including nearly 1.4 million ground stations and 451,000 line kilometers of airborne surveys, were compiled to create this grid. The Australian Ocean Data Network released this dataset, which integrates ground, airborne, and offshore gravity data up to September 2019. It represents the tilt filter of complete Bouguer anomalies across Australia and its continental margins.

Use Cases

• Map subsurface geological structures by interpreting the tilt filter grid of complete Bouguer anomalies.
• Model crustal density variations using gravity anomaly values derived from ground and airborne observations.
• Integrate airborne gravity gradiometry line data to improve resolution in regions with sparse ground station coverage.
• Analyze terrain corrections applied using combined offshore bathymetry and onshore topography data.
• Assess continental margin geology by examining the grid's coverage extending beyond the Australian coastline.

Strengths

• Integrates approximately 1.8 million gravity observations from multiple sources.
• Combines 1.4 million ground stations with 451,000 line km of airborne gravity and gradiometry surveys.
• Provides a consistent 0.00417-degree cell size grid (approximately 435m) for the entire area.
• Data quality was checked by GA geophysicists to ensure it is fit-for-purpose.

Limitations

• Ground station density is uneven, with spacing varying from 11 km to less than 1 km.
• The core ground observation data is static as of September 2019, though the metadata was updated in 2026.
• Airborne survey line spacing ranges from 0.5 km to 2.5 km, creating variable resolution.

Provenance

Source

Australian National Gravity Database (ANGD), Global Gravity grid v28.1, and airborne surveys.

Collection Method

Data processed via standard geophysical methods, with terrain corrections applied using bathymetry and topography.

Time Range

Ground data collected from the 1940s to September 2019.

Freshness

Grid data current to September 2019; metadata record last updated April 2026.

Geography

Australia and its continental margins.