Thermohaline circulation Oceanography (compound of the Greek words ωκεανός meaning "ocean" and γράφω meaning "to write"), also called oceanology or marine science, is the branch of Earth science that studies the ocean. It covers a wide range of topics, including marine organisms and ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and physical properties within the ocean and across its boundaries. These diverse topics reflect multiple disciplines that oceanographers blend to further knowledge of the world ocean and understanding of processes within it: biology, chemistry, geology,meteorology, and physics as well as geography.

Map of the Gulf Stream by Benjamin Franklin, 1769-1770. Courtesy of the NOAA Photo Library. Humans first acquired knowledge of the waves and currents of the seas and oceans in pre-historic times. Observations on tides were recorded by Aristotle and Strabo. Early modern exploration of the oceans was primarily for cartography and mainly limited to its surfaces and of the creatures that fishermen brought up in nets, though depth soundings by lead line were taken. Although Juan Ponce de León in 1513 first identified the Gulf Stream, and the current was wellknown to mariners, Benjamin Franklin made the first scientific study of it and gave it its name. Franklin measured water temperatures during several Atlantic crossings and correctly explained the Gulf Stream's cause. Franklin and Timothy Folger printed the first map of the Gulf Stream in 17691770.[1][2] When Louis Antoine de Bougainville, who voyaged between 1766 and 1769, and James Cook, who voyaged from 1768 to 1779, carried out their explorations in the South Pacific, information on the oceans themselves formed part of the reports. James Rennell wrote the first scientific textbooks about currents in the Atlantic and Indian oceans during the late 18th and at the beginning of 19th century. Sir James Clark Ross took the first modern sounding in deep sea in 1840, and Charles Darwin published a paper on reefs and the formation of atolls as a result of the second voyage of HMS Beagle in 1831-6. Robert FitzRoy published a report in four volumes of the three voyages of the Beagle. In 1841–1842 Edward Forbes undertook dredging in the Aegean Sea that founded marine ecology. As first superintendent of the United States Naval Observatory (1842–1861) Matthew Fontaine Maury devoted his time to the study of marine meteorology, navigation, and charting prevailing winds and currents. His Physical Geography of the Sea, 1855 was the first textbook of oceanography. Many nations sent oceanographic observations to Maury at the Naval Observatory, where he and his colleagues evaluated the information and gave the results worldwide distribution.[3] The steep slope beyond the continental shelves was discovered in 1849. The first successful laying of transatlantic telegraph cable in August 1858 confirmed the presence of an underwater "telegraphic plateau" mid-ocean ridge[dubious – discuss]. After the middle of the 19th century, scientific societies were processing a flood of new terrestrial botanical and zoological information. In 1871, under the recommendations of the Royal Society of London, the British government sponsored an expedition to explore world's oceans and conduct scientific investigations. Under that sponsorship, the Scots Charles Wyville Thompson and Sir John Murray launched the Challenger

there is a major research institution: National Oceanography Centre. Oceanographic institutes dedicated to the study of oceanography were founded. surveying the Mid atlantic ridge. is a leading center. Southampton which is the successor to the Institute of Oceanography. 4417 new species were discovered. The Great Global Rift. The Ocean Drilling Project started in 1966. [4] In the 1950s. An oceanographic buoy array was established in the Pacific to allow prediction of El Niño events. For this deep water mission the Western Union Cable vessel the Lord Kelvin was converted to the ability to lower a cable down several miles. The results of this were published in 50 volumes covering biological. Between 1925 and 1927 the "Meteor" expedition gathered 70. these included the Scripps Institution of Oceanography in 1892. Ocean currents (1911) In 1893. running along the Mid Atlantic Ridge. Virginia Institute of Marine Science in 1938. In Britain. Lamont-Doherty Earth Observatory at Columbia University. In 1939 the Carnegie Institution assigned Dr. Piggot the mission of exploring the sea bed for Radium deposits. 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. Charles S.S.[5] From the 1970s. which had a unit attached that fired a hollow dart into the sea bed floor which was then raised with the seabed sample for analysis. Fridtjof Nansen allowed his ship "Fram" to be frozen in the Arctic ice. In the United States. known as CMAR. . In 1962 there was the first deployment of FLIP (Floating Instrument Platform). The nuclear submarine Nautilus made the first journey under the ice to the North Pole in 1958. Other European and American nations also sent out scientific expeditions (as did private individuals and institutions). The theory of seafloor spreading was developed in 1960 by Harry Hammond Hess. The first purpose built oceanographic ship. the "Albatros" was built in 1882. physical and geological aspects. in 1966. the U. NOAA was put in charge of exploring and studying all aspects of Oceanography in the USA. CSIRO Marine and Atmospheric Research. It also enabled theNational Science Foundation to award Sea Grant College funding to multi-disciplinary researchers in the field of oceanography. The first acoustic measurement of sea depth was made in 1914.000 ocean depth measurements using an echo sounder. Congress created a National Council for Marine Resources and Engineering Development. The four-month 1910 North Atlantic expedition headed by Sir John Murray and Johan Hjort was at that time the most ambitious research oceanographic and marine zoological project ever. In 1921 the International Hydrographic Bureau (IHB) was formed in Monaco. Then. As a result he was able to obtain oceanographic data as well as meteorological and astronomical data. and led to the classic 1912 book The Depths of the Ocean. Auguste Piccard invented the bathyscaphe and used the "Trieste" to investigate the ocean's depths. The first international organization of oceanography was created in 1902 as the International Council for the Exploration of the Sea. In Australia.expedition (1872–1876). 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. a 355 foot spar buoy. Deep sea vents were discovered in 1977 by John Corlis and Robert Ballard in the submersible "Alvin". Woods Hole Oceanographic Institution in 1930. and the School of Oceanography at University of Washington.

The Physical Geography of the Seas and Its Meteorology (1855) Branches Oceanographic frontal systems on the Southern Hemisphere The study of oceanography is divided into branches:     Biological oceanography investigates the ecology of marine organisms in the context of the physical. . The atmosphere and ocean are linked because of evaporation and precipitation as well as thermal flux(and solar insolation). one visible. Physical oceanography. Our planet is invested with two great oceans.N. the other covers about two thirds of its surface. though the latter has more emphasis on the biology of individual marine organisms. in the design and building of oil platforms.[7] Oceanographic data management is the discipline ensuring that oceanographic data both past and present are available to researchers. studies the ocean's physical attributes including temperature-salinity structure. In 1942. These branches reflect the fact that many oceanographers are first trained in the exact sciences or mathematics and then focus on applying their interdisciplinary knowledge. waves. It is closely aligned with marine biology. Chemical oceanography. ships. is the study of the geology of the ocean floor including plate tectonics and paleoceanography. and geological characteristics of their ocean environment. seawater and geology) edited by M. internal tides. mixing. Hill was published in 1962 while the "Encyclopedia of Oceanography" by Rhodes Fairbridge was published in 1966. or marine chemistry. Geological oceanography. potential global warming and related biosphere concerns. Sverdrup and Fleming published "The Ocean" which was a major landmark. Geosat seafloor mapping data became available in 1995. the other invisible. skills and abilities to oceanography. internal waves. one underfoot. surface tides. "The Sea" (in three volumes covering physical oceanography. harbours. or marine physics. or marine geology. one entirely envelopes it. is the study of the chemistry of the ocean and its chemical interaction with the atmosphere. Maury.[6] Data derived from the work of Oceanographers is used in marine engineering. and other structures that allow us to use the ocean safely.1990 saw the start of the World Ocean Circulation Experiment (WOCE) which continued until 2002. the other overhead. —Matthew F. and currents. chemical. Connection to the atmosphere The study of the oceans is linked to understanding global climate changes. Wind stress is a major driver of ocean currents while the ocean is a sink for atmospheric carbon dioxide.