History of geophysics
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.
Lucretius claimed Mount Etna was completely hollow and the fires of the underground driven by a fierce wind circulating near sea level.
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.
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.
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.
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.
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.
Beno Gutenberg and Harold Jeffreys worked at explaining the difference in Earth's density due to compression and the shear velocity of waves.
[6] Scientists who have contributed to advances in knowledge about the Earth's interior and seismology include Emil Wiechert, Beno Gutenberg, Andrija Mohorovičić, Harold Jeffreys, Inge Lehmann, Edward Bullard, Charles Francis Richter, Francis Birch, Frank Press, Hiroo Kanamori and Walter Elsasser.
[8] In the second half of the 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.
Alexander von Humboldt observed in the early 19th century the geometry and geology of the shores of continents of the Atlantic Ocean.
[9] James Hutton and Charles Lyell brought about the idea of gradual change, uniformitarianism, which helped people cope with the slow drift of the continents.
The German "Meteor" expedition gathered 70,000 ocean depth measurements using an echo sounder, surveying the Mid-Atlantic Ridge between 1925 and 1927.
[13] Distortions to the Earth's magnetic field cause the phenomenon Aurora Borealis, commonly called the Northern Lights.
[14] The Earth's climate changes over time due to the planet's atmospheric composition, the sun's luminosity, and the occurrence of catastrophic events.
[16] The ocean is capable of absorbing carbon dioxide from the atmosphere, but this varies based on the levels of nitrogen and phosphorus present in the water.
[21] Impacts from large celestial bodies, commonly asteroids, create shock waves that push air and distribute dust into the atmosphere, blocking sunlight.
Geological features, called traps, that commonly indicate the presence of oil, can be identified from the model and used to determine suitable sites to drill.
