Good earth: Geophysics investigates the fundamental structure and evolution of our planet

If rocks, minerals and fossils fascinate you, you enjoy outdoor field trips and are good at maths and physics, then geophysics is an area of study you can consider. Geophysics investigates the fundamental structure and evolution of our planet. It is concerned with the movement of the tectonic plates on the earth’s surface by a few centimetres per year, the movement of the direction in which the compass needle points by hundredths of degrees per year, and the gradual rise of land once covered by ice sheets. That all these processes are related to each other, and require study from the microscale to the planetary scale, and on time scales of milliseconds to billions of years, is what makes geophysics so exciting and challenging.

Geophysics is the study of the earth’s features with the help of theories of physics in areas such as gravity, magnetism, electricity, light, sound, heat and radioactivity. Geophysics helps to analyse earthquakes and atmospheric changes.

There are many divisions of geophysics, including oceanography, atmospheric physics, climatology, petroleum geophysics, environmental geophysics, engineering geophysics and mining geophysics.

What do I have to do?

Professionals in geophysics use quantitative physical methods to study the earth, especially by seismic reflection and refraction, gravity, magnetic, electrical, electromagnetic, and radioactivity methods. They investigate sub-surface conditions in the earth through measurement, analysis and interpretation of physical fields at the surface. Studies are used to determine what is directly below the surface or further below. Many of these technologies are traditionally used for exploring economic materials such as groundwater, metals, oil, natural gas and hydrocarbons.

Geophysicists measure physical properties such as the density, electrical resistivity, electrical fields and radioactivity of rocks; the velocity of sound waves transmitted through the ground; the changes in gravity and magnetic fields of the earth and the reflection of radio signals from rocks near the earth’s surface.

The methods or techniques most commonly employed by practitioners include:

electromagnetics, ground-penetrating radar (GPR), magnetics, resistivity (or induced polarisation), seismic refraction (or near surface seismic reflection) and spontaneous potential (or SP).

Physical fitness is important in this field as you may have to work in demanding weather conditions and environments.

What should I study?

You should complete Plus Two with physics, chemistry and maths. To be a professional geophysicist, you must have an MSc or MTech degree in geophysics. The topics you study will include geomagnetism, oceanography, seismology, and volcanology; the analysis and interpretation of global magnetic field data collected by satellites; theoretical methods in geomagnetism (Euler and other gradient-based techniques); environmental geomagnetism (magnetisation of drums); continental rifts (New Madrid Seismic Zone, Kenya Rift); velocity-density relationships; integrated geologic and geophysical interpretation.

You are required to double-check data and experiment results using critical thought, observation and analysis. Work in this field requires good judgement and power of observation, clear logical thought and the ability to carry out practical experiments.

What next?

The conventional jobs in geophysics are with oil companies. Geophysicists are also recruited by environmental companies, the Geological Survey of India (GSI), the Central Ground Water Board, government undertakings like the Oil and Natural Gas Commission, Coal India, the National Geophysical Research Institute at Hyderabad, the Centre for Earth Studies at Thiruvananthapuram, Mineral Exploration Corporation Ltd, the National Institute of Hydrology, the Indian Institute of Tropical Meteorology, the Indian Institute of Himalayan Geology at Dehradun, engineering firms, software companies, colleges and universities. You may also consider taking up private consultancy work.

where to study

• Indian Institute of Technology, Kharagpur.
• Guru Nanak Dev University, Amritsar.
• National Geophysical Research University, Hyderabad.
• Indian Institute of Technology, Roorkee.
• Cochin University of Science and Technology, Kochi.