This image is a greyscale image of the Total Magnetic Intensity (TMI) Anomaly Image of Australia with Variable Reduction to Pole (VRTP). Total magnetic intensity (TMI) data measures variations in the intensity of the Earth magnetic filed caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. A variable reduction to Pole is aimed at locating magnetic anomalies exactly above their source bodies and without any distortion. The image is created from the 2019 variable reduction to Pole of the TMI grid with a grid cell size of ~3 seconds of arc (approximately 80 m). This image only includes airborne-derived TMI data for onshore and near-offshore continental areas. The image provides a better interpretation of the magnetic data by giving an accurate location of magnetic source bodies.

Total magnetic intensity (TMI) data measures variations in the intensity of the Earth magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The 2019 Total magnetic Intensity (TMI) grid of Australia has a grid cell size of ~3 seconds of arc (approximately 80 m). This grid only includes airborne-derived TMI data for onshore and near-offshore continental areas. Since the sixth edition was released in 2015, data from 234 new surveys have been added to the database, acquired mainly by the State and Territory Geological Surveys. The new grid was derived from a re-levelling of the national magnetic grid database. The survey grids were levelled to each other, and to the Australia Wide Airborne Geophysical Survey (AWAGS), which serves as a baseline to constrain long wavelengths in the final grid. It is estimated that 33 500 000 line-kilometres of survey data were acquired to produce the 2019 grid data, about 2 000 000 line-kilometres more than for the previous edition.

This image is a greyscale image of the Total Magnetic Intensity of Australia. Total magnetic intensity (TMI) data measures variations in the intensity of the Earth magnetic filed caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The image is created from the 2019 TMI grid with a grid cell size of ~3 seconds of arc (approximately 80 m). This image only includes airborne-derived TMI data for onshore and near-offshore continental areas. The image shows the magnetic response of subsurface features with contrasting magnetic susceptibilities. The image can also be used to locate structural features such as dykes.

The thorium over potassium grid is a derivative of the 2019 radiometric or gamma-ray grid of Australia. The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data are collected on airborne geophysical surveys conducted by Commonwealth, State and Northern Territory Governments and the private sector. The 2019 thorium over potassium was derived by seamlessly merging over 600 airborne gamma-ray spectrometric surveys. The final grid has a cell size of about 100m (0.001 degrees) and is derived from the filtered thorium and potassium grids.

The uranium over potassium grid is a derivative of the 2019 radiometric or gamma-ray grid of Australia comprising over 600 airborne gamma-ray spectrometric surveys. The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data are collected on airborne geophysical surveys conducted by Commonwealth, State and Northern Territory Governments and the private sector. The 2019 uranium over potassium grid has a cell size of about 100 m (0.001 degrees) and is derived from the filtered uranium and potassium grids.

The unfiltered terrestrial dose rate grid is a derivative of the 2019 radiometric or gamma-ray grid of Australia, which is a merge of over 600 individual gamma-ray spectrometric surveys. The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data are collected on airborne geophysical surveys conducted by Commonwealth, State and Northern Territory Governments and the private sector. The unfiltered terrestrial dose rate grid is derived as a linear combination of the unfiltered K, U and Th grids, and has a cell size of about 100m (0.001 degrees).

The filtered uranium grid is a derivative of the 2019 radiometric or gamma-ray grid of Australia. The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data are collected on airborne geophysical surveys conducted by Commonwealth, State and Northern Territory Governments and the private sector. The 2019 filtered uranium grid was derived by seamlessly merging over 600 airborne gamma-ray spectrometric surveys. The final grid has a cell size of about 100m (0.001 degrees) and shows uranium element concentrations of the Australia region.

The filtered thorium grid is a derivative of the 2019 radiometric or gamma-ray grid of Australia. The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data are collected on airborne geophysical surveys conducted by Commonwealth, State and Northern Territory Governments and the private sector. The 2019 filtered thorium grid was derived by seamlessly merging over 600 airborne gamma-ray spectrometric surveys. The final grid has a cell size of about 100m (0.001 degrees) and shows thorium element concentrations of the Australia region.

The unfiltered potassium grid is a derivative of the 2019 radiometric grid of Australia. The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data are collected on airborne geophysical surveys conducted by Commonwealth, State and Northern Territory Governments and the private sector. The 2019 unfiltered potassium grid has a cell size of about 100 m (0.001 degrees) and shows potassium element concentrations of the Australia region. Potassium is the seventh most abundant element in the Earth's crust. The potassium concentration grid can be used to locate minerals and compounds containing potassium.

The uranium over thorium grid is a derivative of the 2019 radiometric or gamma-ray grid of Australia which is a merge of over 600 individual gamma-ray spectrometric surveys. The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data are collected on airborne geophysical surveys conducted by Commonwealth, State and Northern Territory Governments and the private sector. The 2019 uranium over thorium grid has a cell size of about 100 m (0.001 degrees) and is derived from the filtered uranium and thorium grids.