Why use geophysics? Geophysics is the study of the physics of the Earth and its environment in space
Geophysics is a scientific discipline that focuses on studying the physical properties and processes of the Earth and other celestial bodies. It involves using principles and techniques from physics to investigate the Earth’s interior, its surface, and its interactions with various forces and energies. Geophysics plays a crucial role in understanding the structure, composition, and behaviour of the Earth and in addressing geological, environmental, and natural resource-related questions.
Geophysicists employ a wide variety of methods and instruments to gather data about the Earth’s properties. Some common techniques used in geophysics include seismology, where seismic waves generated by earthquakes or man-made sources are used to map the Earth’s interior structure, including the different layers, such as the crust, mantle, and core. It also includes TEM (transient electromagnetic) which uses electromagnetic fields to investigate the Earth’s subsurface by measuring how currents diffuse in the geological layers.
It has wide-ranging applications across industries, contributing to resource exploration, environmental management, infrastructure development, archaeology, and climate research. By employing geophysical instruments, informed decisions can be made, mitigate risks, and ensure sustainable practices in their respective fields
What types of problems are addressed?
You can find a number of problems addressed in the ‘Case studies’ section of this website.
What geophysical applications are possible?
Explore our product range to discover the types of applications for using TEMcompany instruments.
What is Transient Electromagnetic (TEM)?
The sTEM & tTEM instruments both transmit electromagnetic fields into the ground. In general, the TEM method works by turning off a strong current running in the transmitter loop placed on the ground surface. This current can be in the order of 1 – 30 Amp, and it is turned off in an amazing 2 – 5 millionth of a second. Turning the current off induces currents in the subsurface, and these currents diffuse downwards and outwards, very similar to smoke rings. In this diffusion process, the currents are turned into heat, so they change magnitude, and hence, their associated magnetic fields will also change magnitude. It is the rate of change of the magnetic fields which gives a changing flux in the receiver coil, and this gives a voltage change measured by the receiver. An entire measurement typically takes from 1 – 10 thousand of a second, and to get a signal, this process is repeated hundreds of times per second. The rate of change of the measured voltage is dependent on the conductivity of the subsurface layers
Other geophysical methods:
- Gravity and Gravimetry: Measuring variations in the Earth’s gravitational field to infer information about subsurface density variations, such as the presence of underground structures like mountains or oil reservoirs.
- Magnetometry: Measuring variations in the Earth’s magnetic field to identify and map subsurface geological features, including faults and mineral deposits.
- Geodesy: Precisely measuring the Earth’s shape, rotation, and gravitational field to understand processes like plate tectonics and sea-level changes.
- Remote Sensing: Collecting data from satellites and aircraft to study changes in the Earth’s surface, such as land deformation, vegetation health, and ocean currents.
- Geothermal Methods: Studying the Earth’s heat flow and thermal properties to understand processes like mantle convection and energy extraction from the Earth’s interior.
- Ground Penetrating Radar (GPR): Using radar pulses to image the subsurface and detect buried objects or structures.
