History of geophysics
Encyclopedia
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 one is economical usage of Earth resources (ore deposits, petroleum, water resources, etc.) and Earth-related hazards such as earthquakes, volcanoes, tsunamis, tides, and floods.
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 divided into four elemental forces: Earth, Air, Fire and Water. Empedocles
maintained 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. 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
.
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 the tides and the precession of the equinox.
Then 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 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 the 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.
Physics of Earth’s interior and seismology
were developed by Emil Wiechert
, Beno Gutenberg
, Andrija Mohorovičić
, Harold Jeffreys
, Inge Lehmann
, Edward Bullard
, Charles Francis Richter
, Francis Birch
, Frank Press
, Hiroo Kanamori
and Walter Elsasser.
In the second half of 20th century, plate tectonics
theory was developed by several contributors including Alfred Wegener
, Maurice Ewing
, Robert S. Dietz
, Harry Hammond Hess
, Hugo Benioff
, Walter C. Pitman, III
, Frederick Vine, Drummond Matthews
, Keith Runcorn
, Bryan L. Isacks, Edward Bullard
, Xavier Le Pichon
, Dan McKenzie, W. Jason Morgan
and John Tuzo Wilson.
Advances in physical oceanography
occurred in the 20th century. Sea depth by acoustic measurements of was first made in 1914. The German "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 Program
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 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.
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.
He discussed geophysics in letters to his former teacher, Christian Friedrich Schönbein
.
The word geophysics appeared in print only a few times between 1834 and
the 1880s. An 1848 edition of the encyclopedia Meyers Großes Conversationslexikon
included the article "Geophysik", perhaps written by Fröbel.
Carl Friedrich Naumann 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 restricted meaning.
The term geophysics appeared sporadically through the 1860s and 1870s in Germany. Adolph Muhry used it in association with meteorology and climatology in 1863. In the 1870s, Georg von Neumayer
applied it to the oceans and Ferdinand von Richthofen
to the solid Earth. Related terms were used in English, Italian, and probably in other languages. In 1840, John Herschel
wrote of terrestrial physics and physical geography. Angelo Secchi
, Ernesto Sergent, and Francesco Denza
, among other Italians, preferred the term fisica terrestre. Secchi (1879) and Sergent (1868)) presented physical terrestrial topics for students. Denza (1882) discussed meteorology specifically as a part of terrestrial physics. In Turkish, the word Arzi Fiziki that means geophysics appeared in 1920s in the name of Kandilli Observatory as "Arzi Fiziki Kandilli Rasathanesi".
The problem of foundation of geophysics as an independent scientific discipline has been discussed by Wilfried Schröder. General research into the 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.
Geophysics
Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...
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 one is economical usage of Earth 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, Erastothenes of Cyrene measured the circumference of the Earth, using trigonometry and the angle of the Sun at more than one latitude in Egypt.There is some information about earthquakes in Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
's Meteorology, in Naturalis Historia
Naturalis Historia
The Natural History is an encyclopedia published circa AD 77–79 by Pliny the Elder. It is one of the largest single works to have survived from the Roman Empire to the modern day and purports to cover the entire field of ancient knowledge, based on the best authorities available to Pliny...
by Pliny the Elder
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
, and in Strabo
Strabo
Strabo, also written Strabon was a Greek historian, geographer and philosopher.-Life:Strabo was born to an affluent family from Amaseia in Pontus , a city which he said was situated the approximate equivalent of 75 km from the Black Sea...
's Geographica
Géographica
Géographica is the French-language magazine of the Royal Canadian Geographical Society , published under the Society's French name, the Société géographique royale du Canada . Introduced in 1997, Géographica is not a stand-alone publication, but is published as an irregular supplement to La...
. Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
and Strabo
Strabo
Strabo, also written Strabon was a Greek historian, geographer and philosopher.-Life:Strabo was born to an affluent family from Amaseia in Pontus , a city which he said was situated the approximate equivalent of 75 km from the Black Sea...
recorded observations on tides.
A natural explanation of volcanoes was first undertaken by the Greek philosopher Empedocles
Empedocles
Empedocles was a Greek pre-Socratic philosopher and a citizen of Agrigentum, a Greek city in Sicily. Empedocles' philosophy is best known for being the originator of the cosmogenic theory of the four Classical elements...
(c. 490-430 B.C.), who considered the world divided into four elemental forces: Earth, Air, Fire and Water. Empedocles
Empedocles
Empedocles was a Greek pre-Socratic philosopher and a citizen of Agrigentum, a Greek city in Sicily. Empedocles' philosophy is best known for being the originator of the cosmogenic theory of the four Classical elements...
maintained volcanoes were manifestation of Elemental Fire. Winds and earthquakes would play a key role in explanations of volcanoes. Lucretius
Lucretius
Titus Lucretius Carus was a Roman poet and philosopher. His only known work is an epic philosophical poem laying out the beliefs of Epicureanism, De rerum natura, translated into English as On the Nature of Things or "On the Nature of the Universe".Virtually no details have come down concerning...
, claimed Mount Etna
Mount Etna
Mount Etna is an active stratovolcano on the east coast of Sicily, close to Messina and Catania. It is the tallest active volcano in Europe, currently standing high, though this varies with summit eruptions; the mountain is 21 m higher than it was in 1981.. It is the highest mountain in...
was completely hollow and the fires of the underground driven by a fierce wind circulating near sea level. Observations by Pliny the Elder
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
noted the presence of earthquakes preceded an eruption. Athanasius Kircher
Athanasius Kircher
Athanasius Kircher was a 17th century German Jesuit scholar who published around 40 works, most notably in the fields of oriental studies, geology, and medicine...
(1602–1680) witnessed eruptions of Mount Etna
Mount Etna
Mount Etna is an active stratovolcano on the east coast of Sicily, close to Messina and Catania. It is the tallest active volcano in Europe, currently standing high, though this varies with summit eruptions; the mountain is 21 m higher than it was in 1981.. It is the highest mountain in...
and Stromboli
Stromboli
Stromboli is a small island in the Tyrrhenian Sea, off the north coast of Sicily, containing one of the three active volcanoes in Italy. It is one of the eight Aeolian Islands, a volcanic arc north of Sicily. This name is a corruption of the Ancient Greek name Strongulē which was given to it...
, 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
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
, bitumen and coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
.
Instrumental and analytical period
De Magnete
De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure is a scientific work published in 1600 by the English physician and scientist William Gilbert and his partner Aaron Dowling...
(1600), in which he deduced that compasses point north because the Earth itself is magnetic. In 1687 Isaac Newton
Isaac Newton
Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...
published his Principia, which not only laid the foundations for classical mechanics
Classical mechanics
In physics, classical mechanics is one of the two major sub-fields of mechanics, which is concerned with the set of physical laws describing the motion of bodies under the action of a system of forces...
and gravitation
Gravitation
Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...
but also explained a variety of geophysical phenomena such as the tides and the precession of the equinox.
Then these experimental and mathematical analyses were applied to several areas of geophysics: Earth’s shape, density, and gravity field (Pierre Bouguer
Pierre Bouguer
Pierre Bouguer was a French mathematician, geophysicist, geodesist, and astronomer. He is also known as "the father of naval architecture"....
; Alexis Clairaut and Henry Cavendish
Henry Cavendish
Henry Cavendish FRS was a British scientist noted for his discovery of hydrogen or what he called "inflammable air". He described the density of inflammable air, which formed water on combustion, in a 1766 paper "On Factitious Airs". Antoine Lavoisier later reproduced Cavendish's experiment and...
), Earth’s magnetic field (Alexander von Humboldt
Alexander von Humboldt
Friedrich Wilhelm Heinrich Alexander Freiherr von Humboldt was a German naturalist and explorer, and the younger brother of the Prussian minister, philosopher and linguist Wilhelm von Humboldt...
, Edmund Halley and Carl Friedrich Gauss
Carl Friedrich Gauss
Johann Carl Friedrich Gauss was a German mathematician and scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics.Sometimes referred to as the Princeps mathematicorum...
), seismology (John Milne
John Milne
For other uses, see John Milne .John Milne was the British geologist and mining engineer who worked on a horizontal seismograph.-Biography:...
and Robert Mallet
Robert Mallet
Robert Mallet FRS , Irish geophysicist, civil engineer, and inventor who distinguished himself in research on earthquakes and is sometimes called the father of seismology.-Early life:...
), and Earth's age
Age of the Earth
The age of the Earth is 4.54 billion years This age is based on evidence from radiometric age dating of meteorite material and is consistent with the ages of the oldest-known terrestrial and lunar samples...
, heat and radioactivity (Arthur Holmes
Arthur Holmes
Arthur Holmes was a British geologist. As a child he lived in Low Fell, Gateshead and attended the Gateshead Higher Grade School .-Age of the earth:...
and William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin OM, GCVO, PC, PRS, PRSE, was a mathematical physicist and engineer. At the University of Glasgow he did important work in the mathematical analysis of electricity and formulation of the first and second laws of thermodynamics, and did much to unify the emerging...
).
There are several descriptions and discussions about a philosophical theory of the water cycle
Water cycle
The water cycle, also known as the hydrologic cycle or H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth. Water can change states among liquid, vapor, and solid at various places in the water cycle...
by Marcus Vitruvius
Vitruvius
Marcus Vitruvius Pollio was a Roman writer, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work De Architectura ....
, Leonardo da Vinci
Leonardo da Vinci
Leonardo di ser Piero da Vinci was an Italian Renaissance polymath: painter, sculptor, architect, musician, scientist, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist and writer whose genius, perhaps more than that of any other figure, epitomized the Renaissance...
and Bernard Palissy
Bernard Palissy
Bernard Palissy was a French Huguenot potter, hydraulics engineer and craftsman, famous for having struggled for sixteen years to imitate Chinese porcelain...
. Pioneers in hydrology
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
include Pierre Perrault
Pierre Perrault (1608–1680)
Pierre Perrault was a Receiver General of Finances for Paris and later a scientist who developed the concept of the hydrological cycle. He and Edme Mariotte were primarily responsible for making hydrology an experimental science.-Life:Perrault grew up in a bourgeois family, had at least seven...
, Edme Mariotte
Edme Mariotte
Edme Mariotte was a French physicist and priest.- Biography :Edme Mariotte was the youngest son of Simon Mariotte, administrator at the district Til-Châtel , and Catherine Denisot . His parents lived in Til-Châtel and had 4 other children: Jean, Denise, Claude, and Catharine...
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 the Daniel Bernoulli
Daniel Bernoulli
Daniel Bernoulli was a Dutch-Swiss mathematician and was one of the many prominent mathematicians in the Bernoulli family. He is particularly remembered for his applications of mathematics to mechanics, especially fluid mechanics, and for his pioneering work in probability and statistics...
's piezometer
Piezometer
A piezometer is either a device used to measure static liquid pressure in a system by measuring the height to which a column of the liquid rises against gravity, or a device which measures the pressure of groundwater at a specific point...
and Bernoulli's equation as well as the Pitot tube
Pitot tube
A pitot tube is a pressure measurement instrument used to measure fluid flow velocity. The pitot tube was invented by the French engineer Henri Pitot Ulo in the early 18th century and was modified to its modern form in the mid-19th century by French scientist Henry Darcy...
by Henri Pitot. In the 19th century, groundwater hydrology was furthered by Darcy's law
Darcy's law
Darcy's law is a phenomenologically derived constitutive equation that describes the flow of a fluid through a porous medium. The law was formulated by Henry Darcy based on the results of experiments on the flow of water through beds of sand...
, the Dupuit-Thiem well formula, and the Hagen-Poiseuille equation
Hagen-Poiseuille equation
In fluid dynamics, the Hagen–Poiseuille equation is a physical law that gives the pressure drop in a fluid flowing through a long cylindrical pipe. The assumptions of the equation are that the flow is laminar viscous and incompressible and the flow is through a constant circular cross-section that...
for flows through pipes. Physical Geography of the Sea, the first textbook of oceanography, was written by Matthew Fontaine Maury
Matthew Fontaine Maury
Matthew Fontaine Maury , United States Navy was an American astronomer, historian, oceanographer, meteorologist, cartographer, author, geologist, and educator....
in 1855.
The thermoscope, or Galileo thermometer
Galileo thermometer
A Galileo thermometer , named after Italian physicist Galileo Galilei, is a thermometer made of a sealed glass cylinder containing a clear liquid and a series of objects whose densities are such that they rise or fall as the temperature changes...
was constructed by Galileo Galilei
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...
in 1607. In 1643, Evangelista Torricelli
Evangelista Torricelli
Evangelista Torricelli was an Italian physicist and mathematician, best known for his invention of the barometer.-Biography:Evangelista Torricelli was born in Faenza, part of the Papal States...
invented the mercury barometer. Blaise Pascal
Blaise Pascal
Blaise Pascal , was a French mathematician, physicist, inventor, writer and Catholic philosopher. He was a child prodigy who was educated by his father, a tax collector in Rouen...
(in 1648) rediscovered that atmospheric pressure decreases with height, and deduced that there is a vacuum above the atmosphere.
20th century
The 20th century was a revolutionary age for geophysics.Physics of Earth’s interior and seismology
Seismology
Seismology is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. The field also includes studies of earthquake effects, such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic,...
were developed by Emil Wiechert
Emil Wiechert
Emil Johann Wiechert was a German geophysicist who presented the first verifiable model of a layered structure of the Earth.-Life:...
, Beno Gutenberg
Beno Gutenberg
Beno Gutenberg was a German-American seismologist who made several important contributions to the science...
, Andrija Mohorovičić
Andrija Mohorovicic
Andrija Mohorovičić was a Croatian meteorologist and seismologist. He is best known for the eponymous Mohorovičić discontinuity and is considered a founder of modern seismology.-Early years:...
, Harold Jeffreys
Harold Jeffreys
Sir Harold Jeffreys, FRS was a mathematician, statistician, geophysicist, and astronomer. His seminal book Theory of Probability, which first appeared in 1939, played an important role in the revival of the Bayesian view of probability.-Biography:Jeffreys was born in Fatfield, Washington, County...
, Inge Lehmann
Inge Lehmann
Inge Lehmann FRS , was a Danish seismologist who, in 1936, argued that the Earth's core is not one single molten sphere, but that an inner core exists which has physical properties that are different from those of the outer core.-Life:Inge Lehmann was born and grew up in Østerbro, a part of...
, Edward Bullard
Edward Bullard
Sir Edward "Teddy" Crisp Bullard FRS was a geophysicist who is considered, along with Maurice Ewing, to have founded the discipline of marine geophysics...
, Charles Francis Richter
Charles Francis Richter
Charles Francis Richter , was an American seismologist and physicist. Richter is most famous as the creator of the Richter magnitude scale which, until the development of the moment magnitude scale in 1979, quantified the size of earthquakes...
, Francis Birch
Francis Birch (geophysicist)
Albert Francis Birch was an American geophysicist best known for his experimental work on the properties of Earth-forming minerals at high pressure and temperature, in 1952 he published a well-known paper in the Journal of Geophysical Research ,where he demonstrated that the mantle is chiefly...
, Frank Press
Frank Press
Frank Press is an American geophysicist.Born in Brooklyn, New York, Press was science advisor to President Jimmy Carter from1976 to 1980,and president of the U.S. NationalAcademy of Sciences from 1981 to 1993...
, Hiroo Kanamori
Hiroo Kanamori
is a Japanese American seismologist who has made fundamental contributions to understanding the physics of earthquakes and the tectonic processes that cause them....
and Walter Elsasser.
In the second half of 20th century, plate tectonics
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
theory was developed by several contributors including Alfred Wegener
Alfred Wegener
Alfred Lothar Wegener was a German scientist, geophysicist, and meteorologist.He is most notable for his theory of continental drift , proposed in 1912, which hypothesized that the continents were slowly drifting around the Earth...
, Maurice Ewing
Maurice Ewing
William Maurice "Doc" Ewing was an American geophysicist and oceanographer.Ewing has been described as a pioneering geophysicist who worked on the research of seismic reflection and refraction in ocean basins, ocean bottom photography, submarine sound transmission , deep sea coring of the ocean...
, Robert S. Dietz
Robert S. Dietz
Robert Sinclair Dietz was Professor of Geology at Arizona State University. Dietz was a marine geologist, geophysicist and oceanographer who conducted pioneering research along with Harry Hammond Hess concerning seafloor spreading, published as early as 1960–1961...
, Harry Hammond Hess
Harry Hammond Hess
Harry Hammond Hess was a geologist and United States Navy officer in World War II.Considered one of the "founding fathers" of the unifying theory of plate tectonics, Rear Admiral Harry Hammond Hess was born on May 24, 1906 in New York City...
, Hugo Benioff
Hugo Benioff
Victor Hugo Benioff was an American seismologist and a professor at the California Institute of Technology. He is best remembered for his work in charting the location of deep earthquakes in the Pacific Ocean....
, Walter C. Pitman, III
Walter C. Pitman, III
Walter Clarkson Pitman, III is a geophysicist and a professor emeritus at Columbia University. His measurements of magnetic anomalies on the ocean floor supported the Morley–Vine–Matthews hypothesis explaining seafloor spreading. With William Ryan, he developed the Black Sea deluge theory...
, Frederick Vine, Drummond Matthews
Drummond Matthews
Drummond Hoyle Matthews FRS was a British marine geologist and geophysicist and a key contributor to the theory of plate tectonics...
, Keith Runcorn
Keith Runcorn
Stanley Keith Runcorn FRS was a British physicist whose paleomagnetic reconstruction of the relative motions of Europe and America revived the theory of continental drift and was a major contribution to plate tectonics.-Biography:He was born in Southport, Lancashire and graduated in engineering...
, Bryan L. Isacks, Edward Bullard
Edward Bullard
Sir Edward "Teddy" Crisp Bullard FRS was a geophysicist who is considered, along with Maurice Ewing, to have founded the discipline of marine geophysics...
, Xavier Le Pichon
Xavier Le Pichon
Xavier Le Pichon is a French geophysicist. Among many other contributions, he is known for his comprehensive model of plate tectonics .He is professor at the Collège de France.-Biography:Le Pichon holds a doctorate in physics....
, Dan McKenzie, W. Jason Morgan
W. Jason Morgan
William Jason Morgan is an American geophysicist who has made seminal contributions to the theory of plate tectonics and geodynamics...
and John Tuzo Wilson.
Advances in physical oceanography
Physical oceanography
Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters.Physical oceanography is one of several sub-domains into which oceanography is divided...
occurred in the 20th century. Sea depth by acoustic measurements of was first made in 1914. The German "Meteor" expedition gathered 70,000 ocean depth measurements using an echo sounder
Echo sounding
Echo sounding is the technique of using sound pulses directed from the surface or from a submarine vertically down to measure the distance to the bottom by means of sound waves. This information is then typically used for navigation purposes or in order to obtain depths for charting purposes...
, surveying the Mid-Atlantic Ridge
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. It separates the Eurasian Plate and North American Plate in the North Atlantic, and the African Plate from the South...
between 1925 and 1927. The Great Global Rift
Mid-ocean ridge
A mid-ocean ridge is a general term for an underwater mountain system that consists of various mountain ranges , typically having a valley known as a rift running along its spine, formed by plate tectonics. This type of oceanic ridge is characteristic of what is known as an oceanic spreading...
was discovered by Maurice Ewing
Maurice Ewing
William Maurice "Doc" Ewing was an American geophysicist and oceanographer.Ewing has been described as a pioneering geophysicist who worked on the research of seismic reflection and refraction in ocean basins, ocean bottom photography, submarine sound transmission , deep sea coring of the ocean...
and Bruce Heezen in 1953 while the mountain range under the Arctic was found in 1954 by the Arctic Institute of the USSR
Arctic and Antarctic Research Institute
The Arctic and Antarctic Research Institute, or AARI is the oldest and largest Russian research institute in the field of comprehensive studies of Arctic and Antarctica...
. The theory of seafloor spreading was developed in 1960 by Harry Hammond Hess
Harry Hammond Hess
Harry Hammond Hess was a geologist and United States Navy officer in World War II.Considered one of the "founding fathers" of the unifying theory of plate tectonics, Rear Admiral Harry Hammond Hess was born on May 24, 1906 in New York City...
. The Ocean Drilling Program
Ocean Drilling Program
The Ocean Drilling Program was an international cooperative effort to explore and study the composition and structure of the Earth's ocean basins. ODP, which began in 1985, was the direct successor to the highly successful Deep Sea Drilling Project initiated in 1968 by the United States...
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
International Geophysical Year
The International Geophysical Year was an international scientific project that lasted from July 1, 1957, to December 31, 1958. It marked the end of a long period during the Cold War when scientific interchange between East and West was seriously interrupted...
or IGY was one of the most important for scientific activity of all disciplines of geophysics: aurora
Aurora (astronomy)
An aurora is a natural light display in the sky particularly in the high latitude regions, caused by the collision of energetic charged particles with atoms in the high altitude atmosphere...
and airglow
Airglow
Airglow is the very weak emission of light by a planetary atmosphere. In the case of Earth's atmosphere, this optical phenomenon causes the night sky to never be completely dark .-Development:The airglow phenomenon was first identified in 1868 by Swedish scientist...
, 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
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
exploration and recovery in the 1920s. Later, petroleum, mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
and groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
geophysics were improved. Earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
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 FröbelJulius Fröbel
Julius Fröbel was a journalist, diplomat and author. He was active in Western Europe, the United States and South America at different times in his life.-Biography:...
He discussed geophysics in letters to his former teacher, Christian Friedrich Schönbein
Christian Friedrich Schönbein
Christian Friedrich Schönbein was a German-Swiss chemist who is best known for inventing the fuel cell and his discoveries of guncotton and ozone.- Life :...
.
The word geophysics appeared in print only a few times between 1834 and
the 1880s. An 1848 edition of the encyclopedia Meyers Großes Conversationslexikon
Meyers Konversations-Lexikon
Meyers Konversations-Lexikon or Meyers Lexikon was a major German encyclopedia that existed in various editions, and several titles, from 1839 until 1984, when it merged with the Brockhaus encyclopedia....
included the article "Geophysik", perhaps written by Fröbel.
Carl Friedrich Naumann 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 restricted meaning.
The term geophysics appeared sporadically through the 1860s and 1870s in Germany. Adolph Muhry used it in association with meteorology and climatology in 1863. In the 1870s, Georg von Neumayer
Georg von Neumayer
Georg Balthazar von Neumayer , was a German polar explorer and scientist who conceived the idea of international cooperation for meteorology and scientific observation....
applied it to the oceans and Ferdinand von Richthofen
Ferdinand von Richthofen
Ferdinand Freiherr von Richthofen was a German traveller, geographer, and scientist.-Biography:He was born in Carlsruhe, Prussian Silesia, and was educated in Breslau and Berlin. He traveled or studied in the Alps of Tyrol and the Carpathians in Transylvania...
to the solid Earth. Related terms were used in English, Italian, and probably in other languages. In 1840, John Herschel
John Herschel
Sir John Frederick William Herschel, 1st Baronet KH, FRS ,was an English mathematician, astronomer, chemist, and experimental photographer/inventor, who in some years also did valuable botanical work...
wrote of terrestrial physics and physical geography. Angelo Secchi
Angelo Secchi
-External links:...
, Ernesto Sergent, and Francesco Denza
Francesco Denza
Francesco Denza was an Italian meteorologist and astronomer.He joined the Barnabites at the age of sixteen, and during his theological course at Rome studied at the same time meteorology and astronomy under Father Angelo Secchi...
, among other Italians, preferred the term fisica terrestre. Secchi (1879) and Sergent (1868)) presented physical terrestrial topics for students. Denza (1882) discussed meteorology specifically as a part of terrestrial physics. In Turkish, the word Arzi Fiziki that means geophysics appeared in 1920s in the name of Kandilli Observatory as "Arzi Fiziki Kandilli Rasathanesi".
The problem of foundation of geophysics as an independent scientific discipline has been discussed by Wilfried Schröder. General research into the 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.