Australian Gravity Anomaly Grid with Airborne Data

Nearly 1.8 million gravity observations underpin this national compilation grid. The Australian government's Geoscience Australia processed ground, marine, and airborne data from the 1940s onward to create this 435-meter cell size raster. It represents de-trended global isostatic residual anomalies across the continent.

Use Cases

• Map subsurface geological structures by interpreting the de-trended global isostatic residual anomaly values.
• Identify density contrasts for mineral exploration using the 0.00417-degree resolution gravity grid.
• Integrate airborne gravity gradiometry line data with ground station observations to improve resolution in sparse areas.
• Model isostatic compensation by analyzing the near-field and far-field isostatic corrections applied to the Complete Bouguer Anomaly data.

Strengths

• Integrates approximately 1.4 million ground stations with 345,000 line-km of airborne gravity and 106,000 line-km of gravity gradiometry data.
• Provides continent-wide coverage of Australia and its margins with a consistent 435-meter grid cell size.
• Data quality was checked by Geoscience Australia geophysicists to ensure fitness for purpose.

Limitations

• Ground station spacing is irregular, varying from 11 km to less than 1 km, creating potential resolution inconsistencies.
• The grid is a static compilation as of September 2019 and does not reflect newer surveys.
• Offshore data is sourced from a global grid (v28.1), which may have lower resolution than the continental data.

Provenance

Source

Geoscience Australia, Australian National Gravity Database, and global data from Scripps Institution of Oceanography/NOAA/NGA.

Collection Method

Processed from ground observations, airborne surveys, and marine data, with isostatic and trend corrections applied to Complete Bouguer Anomaly data.

Time Range

1940s to 2019

Freshness

Grid compilation is from 2019, though metadata was updated in 2026.

Geography

Australia and its continental margins