National Gravity Compilation 2019: First Vertical Derivative Grid of Australia

A 2019 compilation of nearly 1.4 million gravity stations from the Australian National Gravity Database, supplemented by offshore data, provides a detailed view of subsurface geology. The grid has a cell size of approximately 435 meters and represents the first vertical derivative of de-trended global isostatic residual anomalies. Data was acquired by government, industry, and research bodies from the 1940s onward and processed by Geoscience Australia.

Use Cases

• Mapping subsurface geological structures based on gravity anomaly patterns.
• Supporting mineral and resource exploration by identifying density contrasts in the crust.
• Modeling isostatic compensation and crustal thickness across the Australian continent.
• Integrating with other geophysical datasets (e.g., magnetic, seismic) for comprehensive geological interpretation.

Strengths

• Derived from nearly 1.4 million gravity stations, providing dense spatial coverage.
• Station spacing in major parts of the continent is between 2.5 and 7 km, indicating a detailed survey.
• Combines ground observations from the 1940s to 2019 with v28.1 of the Global Gravity grid for offshore coverage.
• Processed using a defined method (FFT on de-trended global isostatic residual anomalies) and checked by GA geophysicists.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• The grid's cell size (0.00417 degrees) may not be suitable for very high-resolution local studies.
• Data may reflect geographic or source bias inherent to the aggregation of surveys over many decades.

Provenance

Source

Geoscience Australia Data, incorporating data from Commonwealth, State, Territory Governments, industry, universities, and Scripps Institution of Oceanography/NOAA/NGA.

Collection Method

Ground and marine gravity observations processed via standard methods and FFT to create a first vertical derivative grid.

Time Range

1940s to September 2019

Freshness

Last updated 2026-04-30 13:08:55.651464; freshness should be verified.

Geography

Australia and its continental margins