Australian National Gravity Anomaly Grid at 435m Resolution

Australia's 2019 National Gravity Compilation grid contains approximately 1.8 million gravity observations processed to reveal sub-surface geological structure. The grid is derived from nearly 1.4 million ground stations in the Australian National Gravity Database, supplemented by offshore data, with ground station spacing ranging from 11 km to less than 1 km. It was produced by Geoscience Australia from data collected by government, industry, and research organizations from the 1940s onward.

Use Cases

• Model geological structure by interpreting the half vertical derivative of de-trended global isostatic residual anomalies grid.
• Target mineral exploration by analyzing spatial patterns in the 0.5VD grid derived from Complete Bouguer Anomaly data.
• Calibrate regional geophysical models using the 435m cell size grid values across the Australian continent and margins.
• Assess data density for survey planning using the documented ground station spacing from 2.5 to 7 km in major parts of the continent.

Strengths

• Approximately 1.8 million gravity observations provide dense spatial coverage.
• Grid cell size of 0.00417 degrees (approximately 435m) offers high resolution.
• Data incorporates ground observations from the 1940s to 2019, offering long-term consistency.

Limitations

• Ground station spacing is inconsistent, varying from 11 km to less than 1 km, creating areas of lower data density.
• The dataset is a 2019 compilation, so newer post-2019 survey data is not included.
• Offshore data is sourced from a global grid (v28.1), which may have different accuracy and resolution than the terrestrial data.

Provenance

Source

Australian National Gravity Database (ANGD) and Scripps Institution of Oceanography global gravity grid.

Collection Method

Ground and marine gravity observations processed via standard methods, FFT, and isostatic corrections.

Time Range

1940s to 2019

Freshness

Data compiled as of September 2019; metadata updated April 2026.

Geography

Australia and its continental margins