Australian Gravity Anomaly Grid With Edge Detection Filter

Australia's 2019 National Gravity Compilation provides a continent-wide grid of de-trended global isostatic residual anomalies with a 435-meter cell size. It integrates nearly 1.4 million ground stations and 451,000 line kilometers of airborne gravity and gradiometry data collected from the 1940s onward by government, industry, and research bodies. The grid is processed with a tilt filter to highlight geological unit edges.

Use Cases

• Mapping geological unit edges by analyzing the tilt filter applied to the DGIR anomaly grid.
• Modeling subsurface density variations using the de-trended global isostatic residual (DGIR) anomaly values.
• Integrating ground and airborne gravity data, specified by 11 km to <1 km station spacing and 0.5 km to 2.5 km line spacing, for regional geological interpretation.

Strengths

• Integrates approximately 1.8 million gravity observations from ground and airborne sources.
• Combines data from a long temporal range, collected from the 1940s to present day.
• Provides high-resolution coverage with a grid cell size of approximately 435 meters.

Limitations

• Ground station spacing is inconsistent, varying from 11 km to less than 1 km across the continent.
• The dataset's core gravity observations are from September 2019, with potential newer surveys not included.
• Offshore data is sourced from a global grid (v28.1) which may have lower resolution than the onshore data.

Provenance

Source

Australian National Gravity Database (ANGD) and Global Gravity grid from Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

Processed from ground observations, airborne gravity, and gravity gradiometry surveys, with a tilt filter applied via Fast Fourier Transform.

Time Range

1940s to 2019 (for core observations).

Freshness

Grid compiled from data current as of September 2019; platform record updated April 2026.

Geography

Australia and its continental margins.