Geophysics

Scientists at Geoscience Australia use the following geophysical methodologies and physical parameters:


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Airborne Electromagnetics

Airborne Electromagnetic data are gathered by transmitting an electromagnetic signal from a system attached to a plane or helicopter. A secondary field is induced in electrically conductive rocks and measured from the same aircraft platform.


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Gravity

The ability to measure small changes in gravity due to changes in the density of the rocks which make up the Earth provides a method which makes it possible to remotely map the distribution of different rock types and the structure of the rocks.


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Magnetics

The magnetic method is a non-invasive geophysical method which measures perturbations in the earth’s magnetic field caused by magnetic minerals in crustal rocks.


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Magnetotellurics

Magnetotellurics (MT) is a passive geophysical method which uses natural time variations of the Earth's magnetic and electric fields to measure the electrical resistivity of the sub-surface.


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Radiometrics

The radiometric, or gamma-ray spectrometric method is a passive geophysical process used to estimate concentrations of the earth’s natural radioelements of potassium, uranium and thorium. The method measures the gamma-rays which the radioactive isotopes of these elements emit during radioactive decay.


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Rock Properties

Rock properties provide the vital link between observed geophysical data and interpreted geology. Geoscience Australia has periodically made measurements of rock properties to support various investigations into the composition and structure of the subsurface.


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Seismic

The seismic survey technique includes refraction, reflection, and passive seismic methods and is the principal geophysical method used in Australia to acquire images of the Earth's crust at depth which provides data on its structure and its resources.