The historical development of geophysics has been motivated by two factors. One of these is the research curiosity of humankind related to planet Earth and its several components, its events and its problems. The second is economical usage of Earth's resources (ore deposits, petroleum, water resources, etc.) and Earth-related hazards such as earthquakes, volcanoes, tsunamis, tides, and floods.
Classical and observational period
In circa 240 BC, Eratosthenes of Cyrene measured the circumference of Earth using geometry and the angle of the Sun at more than one latitude in Egypt.
There is some information about earthquakes in Aristotle's Meteorology, in Naturalis Historia by Pliny the Elder, and in Strabo's Geographica. Aristotle and Strabo recorded observations on tides.
A natural explanation of volcanoes was first undertaken by the Greek philosopher Empedocles (c. 490-430 B.C.), who considered the world to be divided into four elemental forces: earth, air, fire and water. He maintained that volcanoes were manifestation of elemental fire. Winds and earthquakes would play a key role in explanations of volcanoes. Lucretius claimed Mount Etna was completely hollow and the fires of the underground driven by a fierce wind circulating near sea level. Pliny the Elder noted that the presence of earthquakes preceded an eruption. Athanasius Kircher (1602–1680) witnessed eruptions of Mount Etna and Stromboli, then visited the crater of Vesuvius and published his view of an Earth with a central fire connected to numerous others caused by the burning of sulfur, bitumen and coal.
Instrumental and analytical period
Arguably the first modern experimental treatise was William Gilbert's De Magnete (1600), in which he deduced that compasses point north because the Earth itself is magnetic. In 1687 Isaac Newton published his Principia, which not only laid the foundations for classical mechanics and gravitation but also explained a variety of geophysical phenomena such as tides and the precession of the equinox.
These experimental and mathematical analyses were applied to several areas of geophysics: Earth's shape, density, and gravity field (Pierre Bouguer, Alexis Clairaut and Henry Cavendish), Earth's magnetic field (Alexander von Humboldt, Edmund Halley and Carl Friedrich Gauss), seismology (John Milne and Robert Mallet), and the Earth's age, heat and radioactivity (Arthur Holmes and William Thomson, 1st Baron Kelvin).
There are several descriptions and discussions about a philosophical theory of the water cycle by Marcus Vitruvius, Leonardo da Vinci and Bernard Palissy. Pioneers in hydrology include Pierre Perrault, Edme Mariotte and Edmund Halley in studies of such things as rainfall, runoff, drainage area, velocity, river cross-section measurements and discharge. Advances in the 18th century included Daniel Bernoulli's piezometer and Bernoulli's equation as well as the Pitot tube by Henri Pitot. In the 19th century, groundwater hydrology was furthered by Darcy's law, the Dupuit-Thiem well formula, and the Hagen-Poiseuille equation for flows through pipes. Physical Geography of the Sea, the first textbook of oceanography, was written by Matthew Fontaine Maury in 1855.
The thermoscope, or Galileo thermometer, was constructed by Galileo Galilei in 1607. In 1643, Evangelista Torricelli invented the mercury barometer. Blaise Pascal (in 1648) rediscovered that atmospheric pressure decreases with height, and deduced that there is a vacuum above the atmosphere.
Emergence as a discipline
The first known use of the word geophysics was by Julius Fröbel in 1834 (in German). It was used occasionally in the next few decades, but did not catch on until journals devoted to the subject began to appear, beginning with Beiträge zur Geophysik in 1887. The future Journal of Geophysical Research was founded in 1896 with the title Terrestrial Magnetism. In 1898, a Geophysical Institute was founded at the University of Göttingen, and Emil Wiechert became the world's first Chair of Geophysics. An international framework for geophysics was provided by the founding of the International Union of Geodesy and Geophysics in 1919.
20th century
The 20th century was a revolutionary age for geophysics. As an international scientific effort between 1957 and 1958, the International Geophysical Year or IGY was one of the most important for scientific activity of all disciplines of geophysics: aurora and airglow, cosmic rays, geomagnetism, gravity, ionospheric physics, longitude and latitude determinations (precision mapping), meteorology, oceanography, seismology and solar activity.