Australian Gravity Anomaly Grid With First Vertical Derivative

A gravity anomaly image derived from the 2019 Australian National Gravity Grids A series. The underlying grid incorporates nearly 1.4 million gravity stations from the Australian National Gravity Database and offshore data, with a cell size of approximately 435 meters. Data was compiled by Australian government and research bodies from observations dating from the 1940s to 2019.

Use Cases

• Map subsurface geological structures by interpreting the first vertical derivative of the Bouguer anomaly grid.
• Correlate gravity anomaly features with known mineral deposits to identify prospective exploration targets.
• Integrate the 435m resolution grid with other geospatial data like magnetic or seismic surveys for regional geological modeling.
• Study continental margin structures using the combined onshore gravity and offshore marine data coverage.

Strengths

• Integrates nearly 1.4 million gravity station observations from a national database.
• Grid resolution of 0.00417 degrees (approximately 435 meters) provides detailed spatial coverage.
• Data compilation spans observations from the 1940s to 2019, offering historical depth.

Limitations

• Station density is uneven, with spacing varying from 11 km to less than 1 km across the continent.
• The underlying gravity observations are not uniformly distributed, potentially creating regional data gaps.
• The dataset is a processed derivative (image/grid), not the raw point observations.

Provenance

Source

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

Collection Method

Ground and marine gravity observations processed into a spherical cap Bouguer anomaly grid, with a first vertical derivative calculated via Fast Fourier Transform.

Time Range

1940s to 2019.

Freshness

Based on data current as of September 2019, though metadata was updated in April 2026.

Geography

Australia and its continental margins.