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 generate this grid. The grid has a cell size of 0.00417 degrees (approximately 435m) and shows a tilt of the de-trended global isostatic residual anomalies over Australia and its continental margins. The data, processed and quality-checked by Geoscience Australia geophysicists, were collected from the 1940s to September 2019 by government, industry, and research organizations.

Use Cases

• Detecting edges of geological units based on the tilt filter derived from the DGIR grid.
• Modeling subsurface density variations and geological structure based on gravity anomaly data.
• Integrating gravity data with other geophysical surveys for mineral exploration targeting.
• Studying isostatic compensation and crustal thickness variations across the Australian continent.

Strengths

• Derived from nearly 1.4 million gravity stations, providing dense spatial coverage.
• Station spacing in major parts of the continent is between 2.5 and 7 km, indicating a detailed survey.
• Data underwent quality checks by GA geophysicists to ensure it is fit-for-purpose.
• Incorporates ground data collected from the 1940s to 2019, offering a long historical baseline.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Station spacing for ground observations varies from 11 km to less than 1 km, indicating uneven data density.
• The description metadata is limited; actual data quality and specific processing parameters require manual inspection.

Provenance

Source

Geoscience Australia Data, sourced from the Australian National Gravity Database and global marine gravity data.

Collection Method

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

Time Range

Ground data collected from the 1940s to September 2019.

Freshness

Last updated 2026-04-30 14:54:40.767044; freshness should be verified.

Geography

Australia and its continental margins.