Why use geophysics? Geophysics studies the physics of the Earth and its environment in space.
Geophysics is a scientific discipline that studies 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, surface, and interactions with various forces and energies. Geophysics plays a crucial role in understanding the Earth’s structure, composition, and behaviour and in addressing geological, environmental, and natural resource-related questions.
Geophysicists employ various methods and instruments to gather data about the Earth’s properties. Some standard techniques used in geophysics include seismology, where seismic waves generated by earthquakes or manufactured 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, risks mitigated, and sustainable practices ensured in their respective fields.
What types of problems are addressed?
Several problems are addressed in this website’s ‘Case studies’ section.
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. The TEM method generally works by turning off a strong current running in the transmitter loop placed on the ground surface. This cu rent can be in the order of 1 – 30 Amp and turned off in an amazing 2 – 5 millionth of a second. Turning the current off induces currents in the subsurface, which diffuse downwards and outwards, 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. The rate of change of the magnetic fields gives a changing flux in the receiver coil, and this provides a voltage change measured by the receiver. An entire measurement typically takes 1 to 10 thousandths of a second, and to get a signal, this process is repeated hundreds of times per second. The measured voltage’s rate of change depends on the subsurface layers’ conductivity.
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 Earth’s magnetic field variations 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.
