History of geophysics

The historical development of geophysics has been motivated by two factors. One of these is research curiosity of humankind related to Planet Earth and its several components, its events and its problems. The second one is economically usage of Earth resources (ore deposits, petroleum, water resources, etc.) and Earth related hazards (earthquakes, volcanoes, tsunamis, tides, floods, etc.).

Classical and Observational Period

Attempts related to research curiosity were firstly manifested by Thales who live in Miletus where in Asia Minor (now Turkey). His cosmological doctrine was that the Earth originated from "water". Later, Eratosthenes of Cyrene was measured the Earth's circumference.

There are several information and knowledge about earthquakes in “Meteorology” of Aristotle, in “The Natural History” of Pliny the Elder, in “The Geography” of Strabo. The waves and currents of the seas and oceans in pre-historic times were began to acquire knowledge. Aristotle and Strabo recorded observations on tides.

A natural explanation of volcanoes was firstly undertaken by the Greek philosopher Empedocles (c. 490-430 B.C.), who considers the world divided into four elemental forces: Earth, Air, Fire and Water. Empedocles maintained volcanoes as manifestation of Elemental Fire. Winds and earthquakes would play a key role in explanations of volcanoes. Lucretius, claimed Etna was completely hollow and the fires of the underground driven by a fierce wind circulating near sea level. Observations by Pliny the Elder noted 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 Analitical Period

First traces from qualitative geophysics to quantitative geophysics was appeared in William Gilbert's "De Magnet" and in Isaac Newton’s "Principia". Then, these experimental and mathematical analysis were applied to several areas of geophysics : Earth’s shape, density gravity field ( Pierre Bouguer (1698 – 1758); Alexis Clairaut (1713 –1765) and Henry Cavendish (1731-1810)), Earth’s magnetic field (Alexander von Humboldt (1769-1859), Edmund Halley(1656 – 1742) and Carl Friedrich Gauss(1777-1855)), Sismology (John Milne (1850-1913) and Robert Mallet (1810-1881)), Earth's age, heat and radioactivity (Arthur Holmes (1890-1965)and William Thomson, 1st Baron Kelvin (1824-1907).

There are several descriptions and discussions about a philosophical theory of the hydrologic cycle by Marcus Vitruvius, Leonardo da Vinci and Bernard Palissy. Pioneers of water part of Earth (hydrology) include Pierre Perrault, Edme Mariotte and Edmund Halley by studies of rainfall, runoff, drainage area, velocity and river cross-section measurements, discharge, etc. Advances in the 18th century included the Bernoulli piezometer and Bernoulli's equation, by Daniel Bernoulli, the Pitot tube. In the 19th century, groundwater hydrology were developed by Darcy's law, the Dupuit-Thiem well formula, and Hagen-Poiseuille's capillary flow equation. "Physical Geography of the Sea", the first textbook of oceanography, were witten by Matthew Fontaine Maury in 1855.

The thermoscope were constructed by Galileo Galilei in 1607. In 1643, Evangelista Torricelli invents the mercury barometer. Blaise Pascal (in 1648) rediscovers that atmospheric pressure decreases with height, and deduces that there is a vacuum above the atmosphere.

Modern Times

The 20th century was a revolutionary age for geophysics. Physics of Earth’s interior and seismology(Emil Wiechert (1861-1928); Beno Gutenberg (1889-1960); Andrija Mohorovičić (1857-1936); Harold Jeffreys (1891-1989); Inge Lehmann (1888-1993), Edward Bullard(1907-1980), Charles Francis Richter (1900-1985), Francis Birch (1903-1992), Frank Press (1924--), Hiroo Kanamori (1936--) and Walter Elsaser) were shaped the new contributions. In the second half of 20th century, new theory called plate tectonics was born by several contribution (Alfred Wegener, Maurice Ewing (1906-1974), Robert S. Dietz (1914-1995), Harry Hammond Hess(1906-1969), Hugo Benioff(1899-1968), Walter C. Pitman, III (1931--), F.J. Vine, D.H. Matthews, Keith Runcorn (1922-1995), Bryan L. Isacks(1968), Edward Bullard (1907-1980), Xavier Le Pichon (1937--), Dan McKenzie (1942--), W. Jason Morgan (1935--) and John Tuzo Wilson (1808-1993)). In hydrologic sciences, rational analyses began to replace empiricism in the 20th century, while governmental agencies began their own hydrological research programs. Sea depth by acoustic measurements of was firstly made in 1914. The "Meteor" expedition gathered 70,000 ocean depth measurements using an echo sounder, surveying the Mid Atlantic Ridge between 1925 and 1927. The Great Global Rift was discovered by Maurice Ewing and Bruce Heezen in 1953 while the mountain range under the Arctic was found in 1954 by the Arctic Institute of the USSR. The theory of seafloor spreading was developed in 1960 by Harry Hammond Hess. The Ocean Drilling Project started in 1966. There has been much emphasis on the application of large scale computers to oceanography to allow numerical predictions of ocean conditions and as a part of overall environmental change prediction.

As an international scientific effort between 1957 and 1958, the International Geophysical Year or IGY was one of the most important 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.

Industrial applications of geophysics were developed by demand of petroleum exploration and recovery in the 1920s. Later, petroleum, mining and groundwater geophysics were improved. Earthquake hazard minimization, soil/site investigations for earthquake prone areas were a new application of geophysical engineering in the 1990s.

Origin of the word

The word "Geophysik", as far as is known, was first used in 1834 by Julius Fröbel (1805-1893) [Buntebarth, G. (1981) "Zur Entwicklung des Begriffes Geophysik", Abhandlungen derBraunschwiegischen Wissenschaftlichen Gesellschaft 32, 95-109] [ Beck, H. (1961) Alexander von Humboldt, 2 Vols (Wiesbaden: Steiner) ] He discussed geophysics in letters to his former teacher, Christian Friedrich Schönbein (1799-1868). [ Good, G.A., 2000 , The Assembly of Geophysics: Scientific Disciplines as Frameworks of Consensus, Stud. Hist. Phil. Mod. Phys., Vol. 31, No. 3, pp. 259-292. ]

The word geophysics appeared in print only a few times between 1834 andthe 1880s. An article “Geophysik” [ [Anonymous] (1848) &Geophysik', Meyers Grosses Conversationslexikon, 52 Vols (Dresden), Vol. 12, pp. 530ff. ] was printed in Meyers Grosses Conversationslexikon, perhaps written by Fröbel. [Kertz, W. (1979) &Die Entwicklung der Geophysik zur eigenstaKndigen Wissenschaft', Mitteilungen der Gauss-Gesellschaft, No. 16, 41-54.] [Buntebarth, G. (1981) Zur Entwicklung des Begriffes Geophysik', Abhandlungen derBraunschwiegischen Wissenschaftlichen Gesellschaft 32, 95-109]

Carl Friedrich Naumann (1797-1873) used the term in 1849 in a new context in his Lehrbuch der Geognosie, portraying geophysics as one of three parts of the “geognosy of the whole Earth”, along with geodesy and Abyssologie, the science of the deep Earth. He also discussed a geognosy of the peripheral parts of the Earth: geology of the crust, hydrography,and Atmospharologie. Naumann used Geophysik with a more restrictedmeaning.

The term geophysics appeared sporadically through the 1860s and 1870s inGermany. [ Buntebarth, G. (1981) Zur Entwicklung des Begri!es Geophysik', Abhandlungen der Braunschwiegischen Wissenschaftlichen Gesellschaft 32, 95-109.] Adolph Muhry (1810-1888) used it in association with meteorology and climatology in 1863. In the 1870s, Georg von Neumayer (1826-1909) applied it to the oceans and Ferdinand von Richthofen (1833-1905) to the solid Earth. Related terms were used in English, Italian, and probably in other languages, too. In 1840, John Herschel [ Herschel, J. (1840) Terrestrial Magnetism', Quarterly Review, 1840. Reprinted inEssays from the Edinburgh and Quarterly Reviews (London: Longman et al.), pp.63}141 ] wrote of terrestrial physics and physical geography. Angelo Secchi (1818-1878), Ernesto Sergent, and Francesco Denza (1834-1894), among other Italians, preferred the term fisica terrestre. Secchi (1879) [ Secchi, A. (1879) Lezioni elementari di fisica terrestre: coll'aggiunta di due discorsi sopra la grandezza del creato; opera compilata da scritti inediti (Torino and Rome: Ermanno Loescher)] and Sergent (1868)) [ Sergent, E. (1868) Compendio di fisica terrestre e geograxa: ad uso dei giovanetti delle scuole elementari, tecniche e ginnasiali e degli allievi delle scuole popolari e professionali (Milan: Presso Carlo Barbini).] presented physical terrestrial topics for students. Denza (1882) [ Denza, F. (1882) La meteorologia e la fisica terrestre: al III congresso geograxco internazionaledi Venezia (Rome). ] discussed meteorology specically as a part of terrestrial physics. In Turkish, word "Arzi Fiziki" that means geophysics" appeared in 1920's in the name of Kandilli Observatory as "Arzi Fiziki Kandilli Rasathanesi" [ Özçep, F., Orbay, N., (2002). Jeofizik ve Tarihsel Gelişimi, İstanbul Universitesi yayınları, Yayın No:4347, 446 Sayfa, İstanbul] The problem of foundation of geophysics as an independent scientific discipline has been discussed by Wilfried Schröder in "Disziplingeschichte als wissenschaftliche Selbstreflexion historische Wissenschaftsforschung" (P. Lang, Fankfurt/MNain 1982 and in "Emil Wiechert und die Entwicklung der Geophysik " (Arch. Hist. ex. sciences, 1982). General research in history of geophysics has been done by the "commission for history of geophysics and cosmical physics" (Bremen) under the direction of Wilfried Schröder, which published the journal " Berichte der Geschichte der Geophysik und Kosmische Physik".

References

External links

* [http://history.agu.org/ History of Geophysics Committee of AGU]