What is the World Ocean?

The World Ocean, also known as the Global Ocean, refers to the system that forms all the oceans of planet Earth interconnected with each other. It encompasses most of the hydrosphere, covers an area of ​​three hundred and sixty million square kilometers (361,132,000 kmtwo), equivalent to 70.8% of the earth's surfaceand has a total volume of one thousand three hundred million cubic kilometers (1,332,000,000 km3).

It should not be confused with "planetary ocean", a term used in planetology to refer to the global oceanic mass of a planet with any oceans. That is, the World Ocean would be the planetary ocean of the Earth.

the number of oceans

Oceanography or marine sciences is the science that studies the structure, composition and dynamics of the oceans, including physical, chemical, geological and biological processes. In this context, the connection between the different oceans is very important, since the exchange between all of them influences how they behave and global atmospheric phenomena.

The World Ocean is easily visualized on the Fuller projection or Dymaxion map. The display of this icosahedral projection of the globe can be done by looking for the continents or looking for the oceans, and thus a map is obtained that shows a planet dominated by an emerged land mass with a clear continuous connection, or a planet dominated by the oceans. with all connected forming one large body of water surrounding Antarctica: the World Ocean:

The World Ocean is usually divided into smaller parts, the oceans, which are usually defined as large bodies of seawater that separate the continents. Generally 5 oceans are contemplated:

  • major or major oceans: Atlantic, Indian and Pacific (the latter is the largest ocean of all).
  • Secondary or minor oceans: Arctic and Antarctic.

As with the number of continents, the total number of oceans is different in different models. Some models only consider 3 oceans, the three main ones, and include the Arctic Ocean as part of the Atlantic and the Antarctic as part of the Pacific, Indian and Atlantic. Thus, it is possible to go from a model with a single ocean to models with 3, 4 and 5 oceans.

Global ocean currents

Regardless of the number of oceans considered, they are all connected by currents on a global scale. There is a constant movement of water as a result of the deep thermohaline currents (generated by gradients of temperature and saline concentration in seawater) and surface currents generated mainly by the wind.

Cold, saline water is dense and tends to accumulate at the bottom of ocean masses, while warm water is less dense and tends to settle in upper layers. One of the most notable global currents could begin in the Norwegian Sea, where warm water arrives from the Gulf of Mexico displaced by the so-called Gulf Stream, a surface current that crosses the Atlantic Ocean.

The warm water cools on contact with the atmosphere of northern Europe and sinks to deep layers of the ocean. As more warm water reaches northern Europe, it cools and sinks, creating an undercurrent to the south. The deep cold current reaches Antarctica, and from there it moves to other areas where it is heated and reaches the surface again in different regions of the Indian and Pacific Oceans, thus creating a system of global ocean currents known Great Ocean Conveyor Beltone of the main interactions between different parts of the World Ocean.

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