Australian Isostatic Residual Gravity Grids Using Seismic and Elevation Models

2016 and 2019 projects produced isostatic regional gravity anomaly grids for Australia. Geoscience Australia and Intrepid Geophysics created these grids, including a de-trended global isostatic residual (DGIR), using the Airy isostatic compensation method with new elevation and seismic-derived Moho depth models.

Use Cases

• Model crustal thickness by analyzing the de-trended global isostatic residual (DGIR) grid.
• Compare isostatic compensation models using grids derived from Airy-based versus seismic-derived Moho depth.
• Calibrate regional gravity surveys against the benchmark isostatic residual gravity anomaly grid.
• Assess topographic and bathymetric corrections by examining differences between the 2016 and 2019 model outputs.

Strengths

• Grids are benchmark products tested against Geoscience Australia's 2016 and 2019 isostatic models.
• Methodology is documented in a report, detailing the derivation of digital elevation and Moho depth models.
• Comparisons show good similarity with differences typically less than a few micro-metres per second squared.

Limitations

• The seismic-derived Moho depth-based model showed larger differences and is described as sub-optimal.
• Further analyses, such as implementing variable densities for mass calculation, are stated as required.

Provenance

Source

Geoscience Australia and Intrepid Geophysics, published via the Australian Ocean Data Network.

Collection Method

Generated using the Airy isostatic compensation method applied to the 2019 national Complete Bouguer Anomaly (CBA) grid, incorporating new elevation and seismic-derived Moho grids.

Time Range

Projects from 2016 and 2019.

Freshness

null

Geography

Australia