Oceanography

Oceanography is a field of science that studies the seas, oceans and everything related to them, that is, the structure, composition and dynamics of said bodies of water, including from physical processes, such as currents and tides, to geological ones, such as sedimentation or the expansion of the ocean floor, or biological ones. The same science is also known in Spanish as sea sciences, oceanology and marine sciences.

Oceanography is divided into many branches, in relation to their specific contents, such as: physical oceanography, chemical oceanography, geological oceanography, or biological oceanography.

Oceanography as a field of science, is heir to the hydrographic services responsible for the elaboration of nautical charts, created in various countries in the XVIII to collect and systematize the different charters drawn up by the captains of the ships since the time of the discoveries; For example, in Spain, the Hydrography Directorate created in 1797; in France in 1720 or in the United Kingdom in 1795.

Origin of name

The word oceanography (from the Greek ωκεανός, "ocean" and γραφειν, "describe" or "represent graphically") was coined for the first time in the year 1584, from the French océanosophie, but it was short-lived. In 1880 it returned to German as Oceanographie. At the same time, oceanography, in English, appeared correlatively in other languages; oceanography, in Spanish. In the Portuguese language, the word oceanography appears at the end of the XIX century.

The formation of the word is based on the word geography and responds to the scientific origin from which the discipline comes. Modeled on the word geology is oceanologia, first recorded in the English language —oceanology— in 1864. Although some define it as more complete for oceanology, the form that has gained the most popularity is oceanography.

Background of Oceanography as a science

The study of the behavior of the seas goes back to the first adventures of the human being, beyond the coast. For navigational purposes, it was important to know the direction of the prevailing winds and currents, which would facilitate and shorten the duration of the trips; as well as the depth of the waters near the coast or anchoring places, for security reasons.

It is almost certain that phenomena such as tides were early observed, recorded and even predicted; even if we have no written record of it. Aristotle and Strabo were the first to write about this, in the Western world. The first record of the relationship between the tides and the phases of the moon is attributed to Pytheas, in the IV century a. c.; This same philosopher also made a research expedition to the Baltic Sea and the Arctic Circle.

All this information was transmitted orally to the apprentices and kept secret for security and trade reasons; it is possible that some of this information was also transmitted by means such as the tidal rods used by the Polynesian nations to traverse the Pacific Ocean.

The basic notions of life in the sea, would come from the knowledge of the location of the placers or fishing grounds, molluscs, crustaceans, algae and marine mammals, of nutritional value. Aristotle differentiated between marine fish, mammals, molluscs, crustaceans, reptiles and annelids; he formulated that mammals were not true fish because they breathed air. There is a possible myth that Alexander the Great, a student of Aristotle, submerged himself in a barrel with a hose to observe the bottom of the sea.

A basic knowledge of the chemical composition of the sea would allow the use of common salt and the creation of the first salt flats.

In the various maps of ancient civilizations and the Middle Ages, a basic knowledge of marine meteorology can already be observed.

At the beginning of the 15th century, the first school of navigation is believed to have been established in Sagrés, Portugal; where indisputably they were taught in addition to reading and making nautical charts; concepts that today we associate with oceanography, such as the measurement of currents, depths, characterization of bottoms in coastal waters, observation and recording of tides, tidal currents. For this, the Infante Enrique, The Navigator; it had brought together the most illustrious cartographers and experts in matters of the sea and navigation. The so-called Age of Discoveries would mean a formidable advance in the study and knowledge of the oceans; embodied in directions, portulans and navigation charts.

The 18th century, in the Age of Enlightenment, would be key to the consolidation of this knowledge; through the creation of hydrographic organizations in the various Navies that, among other activities, sponsored scientific expeditions such as that of the Spanish Admiral Malespina; Admiral James Cook; the French La Perouse, the British ship Beagle, with Charles Darwin on board, among others.

The expedition of HMS Challenger, substantially modified to be the first oceanographic research vessel, and the subsequent publication of its results in 50 volumes, are considered to mark the formal beginning of oceanography as an independent empirical scientific discipline, within the natural sciences.

Branches of Oceanography

There are four main branches of oceanography: biological oceanography, physical oceanography, geological oceanography, and chemical oceanography.

Biological Oceanography

Biological oceanography, which is not the same as marine biology, studies all marine organisms and their relationship with the environment.

• Oceanography pelagic: Study the biological processes of the piélagos, the open waters of the ocean, far from the coast and off the continental shelf.
• Oceanography neritic: Study the biological processes of the sea near the coast that is covering the continental shelf.
• Oceanography bentónica: Study the biological processes that occur on the surface of the seabed.
• Oceanography demersal: Study the biological processes that occur on the seabed. Term used especially in fishery.

Physical Oceanography

Studys the physical processes that occur in the sea, such as mixing (molecular and turbulent diffusion of the properties of seawater), currents, tides, and waves; as well as the interactions that occur in the border areas with the continental masses, the atmosphere and the seabed. In addition to this, the process of elaboration of nautical charts is considered within this field, since it uses "sui generis" different from cartography.

• Oceanography descriptive: Describes the distribution and characteristics of the water masses in the oceans. It is the marine counterpart of the continental hydrography. It includes the process of developing nautical letters for the hydrographic services of each nation.
• Oceanography dynamic: Study the water movement of the oceans, its causes and the effects on the border with the land masses on coasts and seabeds.
• Oceanography Weather: It is the branch of the physical oceanography that studies the interactions between the atmosphere and the oceans.

Geological Oceanography

Studys the geological processes that affect the oceans.

• Coastal processes: Study the geomorphology and dynamics of coastal bodies such as deltas, estuaries, estuaries, beaches and coastal lagoons.
• Marine sedimentology: Study the transport and deposit of sediments, mainly the erosion and acretion of the beaches and coastal bodies.

Chemical Oceanography

Studys the chemical composition of seawater and organisms. Of the dissolved and particulate components, of their interactions and effects on the hydrosphere, biosphere and atmosphere.

Chemical oceanography can be divided into specific areas of study. For example, marine chemistry deals with the composition of seawater. Marine geochemistry is also concerned with the chemistry of precipitated rocks and sediments found on the ocean floor. Additionally, marine biogeochemistry is concerned with the role of organisms (particularly microorganisms) in altering or forming geological features in the oceans.