National Gravity Compilation 2019: First Vertical Derivative Image of Australia

A gravity anomaly image derived from the 2019 Australian National Gravity Grids A series, showing the first vertical derivative of complete spherical cap Bouguer anomalies. The underlying grid is based on nearly 1.4 million gravity stations from the Australian National Gravity Database and offshore data, with observations collected from the 1940s to 2019. The grid has a cell size of approximately 435 meters and was processed by Geoscience Australia (GA) geophysicists.

Use Cases

• Map subsurface geological structures based on gravity anomaly data.
• Model density variations in the Earth's crust for resource exploration.
• Integrate gravity data with other geophysical datasets for regional geological interpretation.
• Calculate terrain corrections for gravity surveys using the described bathymetry and topography data.

Strengths

• Based on nearly 1.4 million gravity stations from a national database.
• Grid cell size is 0.00417 degrees (approximately 435 meters), providing regional detail.
• Data quality was checked by GA geophysicists to ensure it is fit-for-purpose.
• Incorporates terrestrial data from the 1940s to 2019 and offshore data from global sources.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Station spacing varies from 11 km to less than 1 km, leading to inconsistent resolution.
• Description metadata is limited; actual data quality requires manual inspection after download.

Provenance

Source

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

Collection Method

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

Time Range

1940s to September 2019.

Freshness

Last updated 2026-04-16 09:50:25.603150; freshness should be verified.

Geography

Australia and its continental margins.