National Gravity Compilation 2019 DGIR: De-trended Gravity Anomaly Image of Australia

Approximately 1.8 million gravity observations, including nearly 1.4 million ground stations, were used to generate this grid. The image shows de-trended global isostatic residual anomalies over Australia and its continental margins, derived from data collected from the 1940s to 2019. Geoscience Australia produced this grid from the 2019 Australian National Gravity Grids A series, supplemented with offshore data from global sources.

Use Cases

• Modeling subsurface geological structures based on gravity anomaly patterns.
• Integrating gravity data with other geophysical surveys for mineral exploration.
• Analyzing continental crustal composition and thickness based on isostatic residual calculations.
• Calibrating regional gravity models using a nationally compiled dataset.

Strengths

• Grid cell size of 0.00417 degrees (approximately 435m) provides regional detail.
• Data quality was checked by GA geophysicists to ensure it is fit-for-purpose.
• Incorporates data from multiple sources including government, industry, and academia over decades.
• Uses a standardized processing method to isolate the response from subsurface rocks.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Station spacing for ground observations varies from 11 km to less than 1 km, which may create uneven resolution.
• Freshness should be verified; the underlying data is from 2019, though metadata was updated in 2026.

Provenance

Source

Geoscience Australia, Commonwealth, State and Territory Governments, mining industry, universities, and research organisations.

Collection Method

Ground observations stored in the Australian National Gravity Database (ANGD), supplemented by offshore data from the Scripps Institution of Oceanography, NOAA, and NGA.

Time Range

1940s to 2019

Freshness

Last updated 2026-04-20 00:57:59.080485; underlying data compiled as of September 2019.

Geography

Australia and its continental margins