Australian National Gravity Grid with DGIR Tilt Image

2019 compilation integrates gravity data from the 1940s to present. The dataset combines approximately 1.8 million ground observations, 345,000 line km of airborne gravity, and 106,000 line km of airborne gravity gradiometry to model subsurface geology. It was produced by Geoscience Australia from the Australian National Gravity Database and global sources.

Use Cases

• Edge detection of geological units by applying a tilt filter to the de-trended global isostatic residual (DGIR) grid.
• Interpreting subsurface density variations from Complete Bouguer Anomaly (CBA) data to reveal geological structure.
• Enhancing resolution in areas with poor ground data using airborne gravity and gravity gradiometry survey lines.
• Mapping continental margins by analyzing gravity anomalies over Australia and its offshore regions.

Strengths

• Integrates approximately 1.8 million gravity observations from multiple sources.
• Combines 345,000 line km of airborne gravity and 106,000 line km of airborne gravity gradiometry data.
• Provides a continent-wide grid with a cell size of approximately 435 meters (0.00417 degrees).

Limitations

• Ground station spacing is inconsistent, varying from 11 km to less than 1 km across the continent.
• The dataset's core gravity grid is from 2019, with underlying data dating back to the 1940s, potentially introducing temporal heterogeneity.

Provenance

Source

Geoscience Australia, Australian National Gravity Database, Scripps Institution of Oceanography, NOAA, NGA.

Collection Method

Processed from ground observations, airborne surveys, and global gravity grids using standard geophysical methods and Fast Fourier Transform (FFT) filtering.

Time Range

1940s to 2019 (for source data), compiled in 2019.

Freshness

Last updated in April 2026, but the primary compilation is from 2019.

Geography

Australia and its continental margins.