地球物理学は、地震学、火山学、プレート理論、重力異常や地磁気などの研究領域が含まれる、地球の構造や仕組みを物理的な手法を用いて理解しようとする学問です。世界の産業を支える鉱物資源の確保にとっても重要な研究ですが、それ以上に、絶えず変化し続ける地球の過去を明らかにすること、変化の過程を理解することの重要性を訴えます。
 

• Introduces the important field of geophysics, covering seismology, volcanism, plate tectonics, gravitational anomalies, and the Earth's changing magnetic field as captured in rocks
• Discusses how geophysicists are able to decipher the structure and workings of the Earth - vital to our understanding of the planet's history, and its continuing evolution
• Explains the general approaches and methods used in modern 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 from the Sun and outer space, and thus makes the planet habitable. Lowrie describes how the magnetic field also magnetizes rocks during their formation, leaving a permanent record of the ancient field and its direction that geophysicists have learned to use to interpret past motions of the continents and tectonic plates. From analyses of Earth's deepest interior to measurements made from Earth-orbiting satellites, Lowrie shows how geophysical exploration is vitally important in the search for mineral resources, and emphasizes our need to understand the history of our planet and the processes that govern its continuing evolution.