Australian Gravity Anomaly Grid With First Vertical Derivative

Australia and its continental margins are covered by a gravity anomaly grid with a 0.00417-degree cell size. The image represents the first vertical derivative of de-trended global isostatic residual anomalies, derived from nearly 1.4 million ground and marine gravity stations. Geoscience Australia processed and quality-checked the data, incorporating observations from the 1940s to September 2019.

Use Cases

• Map subsurface geological structures by interpreting the first vertical derivative of de-trended global isostatic residual anomalies.
• Correlate gravity anomaly patterns with known mineral deposits to identify new exploration targets.
• Integrate the gravity grid with magnetic or seismic datasets for enhanced geophysical modeling of the continent.
• Study crustal composition and isostatic equilibrium using the processed de-trended global isostatic residual (DGIR) data.
• Assess data density and station spacing, which ranges from 11 km to less than 1 km, for survey planning.

Strengths

• Derived from nearly 1.4 million gravity stations, providing dense continental coverage.
• Integrates decades of data from government, industry, and research sources, spanning from the 1940s to 2019.
• Grid cell size of 0.00417 degrees (approximately 435m) offers high spatial resolution.

Limitations

• Station spacing is uneven, varying from 11 km to less than 1 km, which may affect model consistency in some regions.
• The underlying ground observations were collected over a 70+ year period with potentially varying instrumentation and standards.
• The grid is a processed derivative product; raw observation data and full metadata are not included in this specific image file.

Provenance

Source

Geoscience Australia, supplemented by global marine data from Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

Ground and marine gravity measurements processed into a national grid, with the DGIR calculated by subtracting isostatic and trend corrections from Complete Bouguer Anomaly data.

Time Range

1940s to September 2019.

Freshness

Grid represents data from the Australian National Gravity Database as of September 2019.

Geography

Australia and its continental margins.