National Gravity Compilation 2019: DGIR Tilt Image of Australia

Geoscience Australia's National Gravity Compilation 2019 DGIR tilt image is derived from approximately 1.8 million gravity observations, including nearly 1.4 million ground stations. The grid has a cell size of 0.00417 degrees (approximately 435m) and integrates data from the 1940s to 2019, sourced from government, industry, and research entities. This processed image applies a tilt filter to de-trended global isostatic residual anomalies to highlight geological edges across Australia and its continental margins.

Use Cases

• Edge detection of geological units based on the applied tilt filter.
• Subsurface density modeling based on gravity anomaly measurements.
• Integrating gravity data with other geophysical surveys for regional geological interpretation.
• Assessing continental margin structures using combined onshore and offshore gravity data.

Strengths

• Integrates approximately 1.8 million gravity observations from multiple sources over decades.
• Grid cell size of 0.00417 degrees (approximately 435m) provides a defined spatial resolution.
• Data quality was checked by GA geophysicists to ensure it is fit-for-purpose.
• Combines ground data from the Australian National Gravity Database with v28.1 of the Global Gravity grid.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Station spacing for ground observations varies from 11 km to less than 1 km, indicating uneven data density.

Provenance

Source

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

Collection Method

Ground and marine gravity observations processed via standard methods, with a tilt filter applied via FFT to the DGIR grid.

Time Range

Data acquired from the 1940s to present, compiled as of September 2019.

Freshness

Last updated 2026-04-10 18:26:29.000861; freshness should be verified.

Geography

Australia and its continental margins.