Geophysics

Geophysics is the physics of the Earth. Central to the Earth Sciences today, it encompasses areas such as seismology, volcanism, plate tectonics, gravitational anomalies, and the Earth's magnetic field (present and past, as captured in rocks), all of which give clues to both the structure and the working of the Earth. In this Very Short Introduction, William Lowrie describes the internal and external processes that affect the planet, as well as the principles and methods of geophysics used to investigate them. He explains how analysis of the seismic waves produced in earthquakes reveals the internal structure of the Earth. Geophysicists have established that the greatest source of energy powering geological processes is the Earth's internal heat. Deep inside the Earth, the temperature is high enough to produce a fluid outer core of molten iron. It is the motion in this molten iron layer that produces the Earth's magnetic field, which shields the planet against harmful radiation...