Australian National Gravity Anomaly Grid with Airborne Data

A 2019 compilation grid of gravity anomalies over Australia and its continental margins, with a cell size of approximately 435 meters. The dataset integrates nearly 1.4 million ground stations and over 450,000 line kilometers of airborne gravity and gradiometry surveys, sourced from government, industry, and research collections dating from the 1940s. It is processed and quality-checked by Geoscience Australia geophysicists to reveal sub-surface geological structure.

Use Cases

• Model crustal thickness and density by interpreting de-trended global isostatic residual anomaly values.
• Identify subsurface geological structures like basins or intrusions from spatial patterns in the gravity unit (gu) grid.
• Integrate airborne gravity gradiometry line data with ground station observations to improve resolution in under-sampled regions.
• Calibrate or validate satellite-derived gravity models using the ground and airborne survey data compiled up to September 2019.

Strengths

• Integrates approximately 1.8 million observations from ground, airborne, and marine sources.
• Provides continental coverage with ground station spacing as dense as 1 km in parts of Australia.
• Includes over 450,000 line kilometers of specialized airborne gravity and gravity gradiometry data.

Limitations

• Ground data density is uneven, with station spacing varying from 1 km to 11 km across the continent.
• The core compilation is from 2019, so newer survey data after September 2019 is not included.
• Offshore data relies on an external global grid (v28.1), which may have different resolution and accuracy.

Provenance

Source

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

Collection Method

Grid generated from processed ground, airborne, and marine gravity measurements, with isostatic corrections applied to Complete Bouguer Anomaly data.

Time Range

Surveys from the 1940s to 2019, compiled as of September 2019.

Freshness

Dataset was last updated in April 2026, but the underlying gravity observation compilation is current only to September 2019.

Geography

Australia and its continental margins.