National Gravity Compilation 2019: Half Vertical Derivative Grid of Australia

Australia and its continental margins are covered by this gravity anomaly grid with a cell size of approximately 435 meters. The grid is derived from nearly 1.4 million ground and marine gravity observations stored in the Australian National Gravity Database as of September 2019, with ground data collected from the 1940s onward. It shows the half vertical derivative of de-trended global isostatic residual anomalies, processed by Geoscience Australia.

Use Cases

• Map subsurface geological structures based on gravity anomaly data.
• Model crustal thickness and density variations for tectonic studies.
• Support mineral and hydrocarbon exploration by identifying density contrasts in the crust.
• Integrate with other geophysical datasets (e.g., magnetic, seismic) for comprehensive geological interpretation.

Strengths

• Derived from nearly 1.4 million gravity observations, providing dense spatial coverage.
• Ground data incorporates measurements from the 1940s to present, offering a long historical baseline.
• Processed and quality-checked by Geoscience Australia geophysicists to be fit-for-purpose.
• Grid cell size of 0.00417 degrees (approx. 435m) offers a relatively high resolution for continental-scale analysis.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Station spacing for ground observations is variable, ranging from 11 km to less than 1 km, which may create inconsistencies in data density.
• Description metadata is limited; actual data quality requires manual inspection after download.

Provenance

Source

Australian National Gravity Database (ANGD) and global marine data from Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

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

Time Range

Ground data collected from the 1940s to present; compilation snapshot as of September 2019.

Freshness

Last updated 2026-06-23 02:36:55.806427; freshness should be verified.

Geography

Australia and its continental margins.