National Gravity Compilation 2019: Airborne DGIR Tilt Grid for Australia

Nearly 1.8 million gravity observations, including 1.4 million ground stations and 451,000 line km of airborne data, were used to create this 2019 grid. The Australian Geological Survey processed ground, offshore, and airborne data to produce a de-trended global isostatic residual (DGIR) tilt grid with a 435m cell size. This compilation integrates data from government, industry, and academic sources collected from the 1940s onward.

Use Cases

• Map subsurface geological edges based on the tilt filter derived from gravity anomalies.
• Model continental crustal density variations based on de-trended global isostatic residual (DGIR) data.
• Integrate airborne gravity gradiometry data to improve resolution in areas with sparse ground observations.
• Analyze long-term changes in Australia's gravity field by comparing with historical compilations.

Strengths

• Integrates approximately 1.8 million gravity observations from multiple sources.
• Includes 345,000 line km of Airborne Gravity and 106,000 line km of Airborne Gravity Gradiometry data for enhanced resolution.
• Data quality was checked by GA geophysicists to ensure it is fit-for-purpose.
• Grid has a fine cell size of 0.00417 degrees (approximately 435m).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect geographic bias inherent to data_gov_au, with variable station spacing across the continent.

Provenance

Source

Australian Ocean Data Network, incorporating data from the Australian National Gravity Database and global sources.

Collection Method

Processed from the 2019 Australian National Gravity Grids B series using a fast Fourier transform (FFT) on DGIR data.

Time Range

1940s to 2019

Freshness

Last updated 2026-06-27 15:54:01.163310; freshness should be verified.

Geography

Australia and its continental margins