University of Queensland Exploration Geophysics Laboratory

What Is Geophysics?

geophysics: the application of physical principles to studies of the earth

The word geophysics implies the amalgamation of geology and physics - the use of physics to study the Earth. In reality, modern geophysics is a broad, high-technology science, which also draws heavily on such disciplines as mathematics, computer science, and instrument engineering. Consequently, geophysics provides career opportunities for professionals with diverse interests and backgrounds.

Exploration geophysics involves the measurement and analysis of physical properties of the Earth. Properties measured include the mass distribution, heat flow, magnetic field strength and elastic properties of the subsurface. These measurements are used to find oil, natural gas, coal, iron, copper, gold and many other minerals. More recently, observation of these physical properties have been used to help solve a range of engineering and environmental problems.

A wide variety of geophysical techniques are used to increase our understanding of the Earth, and help us explore for natural resources. Broadly, each geophysical method is based on a particular physical property. The choice of method for a particular exploration target depends on cost and the likelihood of variations occurring in the associated physical property.

Some methods employed in exploration involve the passive measurement of a physical field, such as the gravity technique associated with measuring lateral variations in density, or the magnetic method which measures changes in the Earth's magnetic field due to differing magnetic properties of subsurface material. Other exploration techniques involve active measurements, such as the seismic method which uses explosive sources to measure elastic properties of the subsurface, or electrical techniques that inject a current, allowing measurement of the resitivities of different rock types.

Figure courtesy of SEG

Exploration geophysicists specialise in the application of geophysical techniques and participate in data collection, field investigation, laboratory studies and research. Geophysicists also work with some of the most powerful supercomputers to process and analyse geophysical data. Geophysicists work in partnership with computer scientists, geologists, engineers, environmental scientists, and business managers.

Want to know more about being an exploration geophysicist?