What is Geophysics?
Geophysics investigates the fundamental structure and evolution of our planet. It involves the application of physical principles to the study of the Earth, and, increasingly, the other planets. Geophysics concerns some of the most violent of phenomena – earthquakes capable of causing hundreds and thousands of deaths, the birth and destruction of planets, volcanic eruptions – and some of the apparently most gentle – the movement of the tectonic plates at the Earth’s surface by only centimetres per year, the movement of the direction in which the compass needle points by hundreths of degrees per year, 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 planetary scale, and on time scales of milliseconds to billions of years, is what makes geophysics so exciting and challenging.
Geophysics is a branch of the Earth sciences that uses quantitative physical methods to elucidate some aspect of the planetary system. Geophysics encompasses large parts of seismology, geodesy (size and form of the Earth), atmospheric science, study of the Earth’s magnetic field, geothermometry, hydrology, oceanography, tectonophysics, geodynamics (study of the inner Earth), exploration and engineering geophysics, geophysical engineering, glaciology, petrophysics, applied geophysics, mineral physics, and engineering geology.