National Gravity Compilation 2019 DGIR Tilt Grid: Geological Edge Detection for Australia

Nearly 1.4 million gravity stations from the Australian National Gravity Database, supplemented by offshore data, were used to create this 435-meter resolution grid. The DGIR tilt grid highlights edges of geological units by applying a fast Fourier transform to de-trended global isostatic residual anomalies. Ground data was collected by government, industry, and research bodies from the 1940s to 2019 and processed by Geoscience Australia geophysicists.

Use Cases

• Detect geological unit boundaries based on the tilt filter ratio of vertical to horizontal derivatives.
• Model subsurface density variations based on gravity anomaly measurements.
• Interpret continental margin structures based on offshore gravity data sourced from global datasets.
• Assess data coverage and station density for specific regions based on described spacing of 2.5 to 7 km over major parts of the continent.

Strengths

• Grid derived from nearly 1.4 million gravity stations out of approximately 1.8 million total observations.
• Data quality was checked by GA geophysicists to ensure it is fit-for-purpose.
• Incorporates ground data collected over decades (1940s to 2019) from multiple government and industry sources.
• Has a defined spatial resolution with a cell size of approximately 435 meters.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect geographic or source bias inherent to the compilation from multiple legacy surveys.

Provenance

Source

Australian Ocean Data Network, incorporating data from the Australian National Gravity Database and global sources (Scripps Institution of Oceanography, NOAA, NGA).

Collection Method

Ground and marine gravity observations processed via standard methods, with a tilt filter applied via fast Fourier transform.

Time Range

Ground data collected from the 1940s to September 2019.

Freshness

Last updated 2026-06-23 02:40:58.325220; freshness should be verified.

Geography

Australia and its continental margins.