Australian Gravity Anomaly Map Derived from 1.4 Million Observations

Over 1.4 million ground gravity observations underpin this de-trended isostatic residual gravity map of Australia. The map integrates decades of government, industry, and research data, including airborne gravity surveys and a global gravity grid, culminating in the 2019 B-Series national grid. It was compiled by the Australian Ocean Data Network using data collected from the 1940s onward.

Use Cases

• Identify subsurface geological structures by analyzing spatial patterns in the de-trended global isostatic residual (DGIR) gravity values.
• Calibrate regional geophysical models using the integrated gravity data from ground stations, airborne surveys (345,000 line km), and gradiometry (106,000 line km).
• Map crustal thickness variations by interpreting the DGIR anomalies, which highlight deviations from isostatic equilibrium.
• Support mineral exploration targeting by correlating specific gravity anomaly features (e.g., -500 to +500 µm.s-2 gradients) with known ore deposits.

Strengths

• Integrates 1.4 million ground gravity observations from the Australian National Gravity Database.
• Combines 345,000 line km of airborne gravity and 106,000 line km of gravity gradiometry data for comprehensive coverage.

Limitations

• Data is presented only as a static PDF map, limiting direct quantitative analysis of the underlying grid values.
• The temporal coverage is broad (1940s-present), which may introduce inconsistencies in measurement techniques over time.

Provenance

Source

Australian Ocean Data Network, combining the Australian National Gravity Database (ANGD) and National Australian Geophysical Database (NAGD).

Collection Method

Integration of ground observations, airborne and gradiometry surveys, and the Scripps Institution of Oceanography Global Gravity Grid.

Time Range

1940s to 2019

Freshness

Based on data compiled as of September 2019.

Geography

Australia