Australian National Gravity Grid 2019 with Airborne DGIR Tilt Filter

Australia and its continental margins are covered by a gravity anomaly grid with a cell size of approximately 435 meters. The grid is derived from nearly 1.4 million ground stations and over 450,000 line kilometers of airborne gravity and gradiometry data, collected from the 1940s to 2019. It was processed by Geoscience Australia to produce a de-trended global isostatic residual (DGIR) tilt grid for geological edge detection.

Use Cases

• Detect edges of geological units based on the DGIR tilt filter described.
• Model subsurface density variations based on processed gravity anomaly data.
• Integrate ground and airborne gravity surveys for regional geological mapping.
• Interpret continental margin structures based on offshore gravity data sourced from global grids.

Strengths

• Integrates approximately 1.8 million gravity observations from ground and airborne sources.
• Includes 345,000 line km of airborne gravity and 106,000 line km of airborne gravity gradiometry data for improved resolution.
• Data quality was checked by GA geophysicists to ensure it is fit-for-purpose.
• Combines data from Commonwealth, State, Territory, industry, and academic sources collected over decades.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Data may reflect geographic and temporal bias inherent to the aggregation of historical surveys.

Provenance

Source

Geoscience Australia (GA), supplemented by offshore data from Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

Processed from ground observations in the Australian National Gravity Database and airborne surveys, with a tilt filter applied via FFT to the DGIR grid.

Time Range

1940s to 2019

Freshness

Last updated 2026-04-10 20:21:59.245593; freshness should be verified.

Geography

Australia and its continental margins