Australian Free-Air and Bouguer Gravity Anomaly Maps at 1:25 Million Scale

Australia is covered by two geophysical maps at a scale of 1:25 million: a Free-air Anomaly Map and a Gravity Map showing Bouguer anomalies on land and free-air anomalies at sea. The maps were prepared from the same data bank as the 1:5 million 1976 Gravity Map of Australia, with additional marine observations from the 'Gulf Rex' vessel. They were drawn by P. Moffat and A.J. Maxwell of the BMR Geophysical Drawing Office and printed by the Division of National Mapping.

Use Cases

• Modeling subsurface geological structures based on gravity anomaly data.
• Integrating gravity data with other geophysical surveys for resource exploration.
• Studying crustal thickness and density variations across Australia and its continental margins.

Strengths

• Includes marine observations from the 'Gulf Rex' vessel, which filled a data gap at the southern end of the Great Barrier Reef.
• Maps are derived from the same data bank as the published 1:5 million 1976 Gravity Map of Australia.
• Detailed methodology and data sources are documented in a referenced publication (Anfiloff et al.).

Limitations

• The underlying data and map creation are from 1976, which may limit relevance for contemporary high-resolution studies.
• Data is presented as static PDF/HTML maps; raw numerical data or vector formats are unavailable.
• Column-level documentation is absent; field semantics must be inferred after download.

Provenance

Source

Geoscience Australia Data

Collection Method

Compiled from a gravity data bank and additional marine surveys.

Time Range

Data compilation circa 1976.

Freshness

Last updated 2026-04-30 15:16:28.673469; freshness should be verified.

Geography

Australia and surrounding marine areas.