It is known as ocean to the sea of immense dimensions that covers most of the earth's surface (according to experts, the 71% ). It is also known as ocean to each of the subdivisions of this sea (Atlantic , peaceful , Indian , etc.). Within these segmentations, the largest ocean is the peaceful .
It is important to underline the existence of what is known as Oceanography. This is the area of Earth Sciences whose clear mission is to study the whole set of processes (chemical, biological, geological ...) that take place both in the oceans and the seas in general.
Starting from the mentioned processes it is necessary to expose that this area, also called Marine Sciences, can be divided into four clearly differentiated branches. Thus, there is the Chemical Oceanography that is responsible for studying and analyzing in depth the chemical composition of what is seawater.
Secondly, we find the Biological Oceanography, which is the one that carries out the study of the whole set of marine beings and organisms. But not only that, because it also does the same about what is the relationship of all of them with the environment in which they are.
The third branch of Oceanography is the so-called Geological. In this case, its mission is to undertake the exhaustive analysis of all the geological processes that affect the oceans. Thus, in this way, it focuses especially on what are the sedimentation or morphology of bodies that are on the coast such as beaches or estuaries.
Finally in fourth place is the Physical Oceanography that is responsible for studying, for example, from the tides to the waves passing through the currents. In turn, it is divided into three areas: meteorological, dynamic and descriptive.
Scholars of geographical and geological issues argue that the ocean emerged around 4 billion years , at a time in history when the surface of the land It cooled to such an extent that it caused the water to go into a liquid state. Its depth depends on each zone analyzed, although it must be said that the average depth revolves around the four kilometers . The deepest part of the ocean is from 11,033 meters , a brand that is in the Mariana Trench .
The surface layer of the ocean has a temperature that oscillates between 12º and the 30º . Underneath, a colder water layer is usually detected, between 5º and -1º . The boundary between both layers is known as thermocline .
The ocean water is salty . Near to 3,5% of the volume of water is formed by materials in solution; when evaporation is high, a large amount of water disappears and only dissolved substances are preserved there, increasing salinity.
In contrast, in the polar regions the salinity is lower, especially during the summer season, since the ice is diluted in the ocean water.
Usually, ocean water never remains in a state of stillness, but instead moves as a result of the formation of waves that are born by the wind that blows on the surface. These waves, which can have different heights, play an important role in shaping the coasts.