National Gravity Compilation 2019 DGIR Grid: De-Trended Isostatic Residual Anomalies

A geospatial grid of gravity anomalies over Australia and its continental margins, derived from approximately 1.8 million ground and marine observations. The grid has a cell size of 0.00417 degrees (approximately 435m) and presents de-trended global isostatic residual anomalies in units of um/s^2. Data was compiled by Geoscience Australia from the Australian National Gravity Database and global sources, with observations collected from the 1940s to 2019.

Use Cases

• Model subsurface geological structure based on gravity anomaly patterns.
• Analyze continental-scale density variations based on processed gravity units.
• Integrate gravity data with other geophysical datasets for regional exploration.
• Study isostatic compensation and crustal thickness based on residual anomaly corrections.

Strengths

• Derived from nearly 1.4 million gravity stations from a total of approximately 1.8 million observations.
• Station spacing for ground observations varies from approximately 11 km down to less than 1 km, with major parts of the continent having spacing between 2.5 and 7 km.
• Data quality was checked by GA geophysicists to ensure fitness for purpose.
• Incorporates offshore data from a global gravity grid developed by Scripps Institution of Oceanography, NOAA, and NGA.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Last updated 2026-05-05 02:09:20.677928; freshness should be verified.

Provenance

Source

Australian National Gravity Database (ANGD) and Global Gravity grid v28.1 from Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

Ground and marine gravity observations processed via standard methods, with de-trended global isostatic residual anomalies calculated by subtracting three correction quantities from Complete Bouguer Anomaly data.

Time Range

Observations collected from the 1940s to September 2019.

Freshness

Data reflects observations up to September 2019; metadata last updated in 2026.

Geography

Australia and its continental margins.