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, prepared from a data bank used for the 1976 Gravity Map of Australia. The Free-air Anomaly map is a smaller version of an unpublished overlay for the 1976 Geological Map, and the Gravity Map shows Bouguer anomalies on land and free-air anomalies at sea. The maps 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 the Bouguer and free-air gravity anomaly data.
• Integrating geological and geophysical interpretations using the map's alignment with the 1976 Geological Map of Australia.
• Analyzing marine gravity observations, particularly in the southern Great Barrier Reef region filled by 'Gulf Rex' data.
• Studying continental-scale geophysical features using the standardized 1:25 million scale maps.

Strengths

• Maps are derived from the authoritative data bank used for the 1976 Gravity Map of Australia.
• Includes supplemental marine observations that fill a significant data gap near the Great Barrier Reef.
• Provides two complementary map types (Free-air and Bouguer anomalies) at a consistent continental scale.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Data is based on 1976 sources and may not reflect recent observations; freshness should be verified.
• Row count is unknown, which may limit suitability assessment for quantitative analysis.

Provenance

Source

Geoscience Australia Data

Collection Method

Prepared from a gravity data bank with added marine observations; techniques detailed in Anfiloff et al.

Time Range

Based on 1976 source maps and data.

Freshness

Last updated 2026-04-20 03:04:17.342624; freshness should be verified.

Geography

Australia, including surrounding marine areas.