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

Two geophysical maps of Australia at a scale of 1:25 million, showing free-air anomalies and Bouguer anomalies on land with free-air anomalies at sea. The maps were prepared from a data bank used for the 1:5 million 1976 Gravity Map of Australia, with additional marine observations from the 'Gulf Rex' vessel. They were drawn by BMR's Geophysical Drawing Office and printed by the Division of National Mapping, Department of National Resources.

Use Cases

• Modeling subsurface density variations based on Bouguer and free-air gravity anomalies.
• Geological mapping and structural interpretation based on gravity anomaly patterns.
• Integrating gravity data with other geophysical datasets for continental-scale studies.
• Educational visualization of Australia's geophysical properties.

Strengths

• Includes marine observations from the 'Gulf Rex' vessel, which filled a data gap at the southern Great Barrier Reef.
• Maps are derived from the same data bank as the published 1:5 million 1976 Gravity Map of Australia.
• Projection details are provided (Simple Conic for Free-air, Lambert Conformal for Gravity).

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Column-level documentation is absent; field semantics must be inferred after download.
• The underlying data and map preparation techniques are from 1976, which may limit modern applicability.

Provenance

Source

Geoscience Australia Data

Collection Method

Prepared from a gravity data bank with additional marine observations.

Freshness

Last updated 2026-04-11 22:59:00.449442; freshness should be verified.

Geography

Australia and surrounding seas