The term of sea recovers several realities.
If the sea is in contact with an ocean it distinguishes from this last by its geographical position generally wedged between terrestrial masses or simply limited by the continental shelf. Ex: The Manche communicates with the Atlantic Ocean by the Celtic Mer, but it is characterized some by its median position between the southern parts from the England and the coasts north from the France. A sea in contact with an ocean can be characterized by particular physical conditions. Ex: the the Mediterranean communicates with the Atlantic Ocean by the Straits of Gibraltar. It is distinguished from the ocean by its position wedged between the Europe, the Asia (the Middle East) and the Africa and by different maritime conditions (differential of temperature between the ocean and the sea, fauna and distinct Flore, Marée of lower amplitude for the the Mediterranean…). Another example: the Sargasso Sea with its accumulation of brown algas to broad of the Florida is distinguished in a completely arbitrary way of the Atlantic Ocean.
The term of sea is also used to indicate certain large Lac S, in particular when they do not have a River in which they flow. It is the case for example of the Caspian Sea or of the Mer of Aral. One speaks then often about closed sea.
The sea includes/understands:
The marine salt is a compound whose complete name in chemistry is Sodium chloride. It tightens to dissolve in water until a concentration of saturation of 359 g/l. If one tries to increase the concentration with beyond this value, by evaporation of water, part of salt returns in a solid state (Solidification or Cristallisation) and settles. The value of the salinity of the seas being largely lower, salt does not settle at the bottom of the seas. As it does not evaporate not either, it is trapped in the sea.
Certain grounds and continental rocks contain salt. When these rocks are exposed to the rain or the flows of subsoil water, part of salt will be dissolved and will join the rivers then the sea. Being given that this salt does not remain but is constantly evacuated, the salinity of the rivers will remain most of the time very low.
The salt deposits can be done naturally when the salt concentration of a sea or a Lac salted increased with by saturation. That can occur in continental zones where there does not exist any flow towards the oceans, like the Dead Sea.
Another case is that of the Mediterranean, which at certain geological times functioned like a saline Marais: its connection with the oceans Straits of Gibraltar being closer, it did not allow the exchanges of water in the two directions like that currently occurs. In addition, evaporation being stronger than precipitations and contributions of fresh water (what is always the case), it is thus a oceanic contribution which made up the deficit. There was thus a salt entry which was compensated by no export. That involved very important salt deposits at the bottom of the Mediterranean and has seems it have also an influence on the salinity of the oceans. Indeed the estimate of the salt contribution to the total ocean by the whole of the rivers during geological times is higher of at least an order of magnitude than the dissolved salt mass in the oceans.
The movements of the sea are complex; for better analyzing them, they are broken up moving elementary, whose causes and laws can be studied separately.
One distinguishes from the undulatory movements , in the form of vertical oscillations:
The movements of the current are horizontal displacements.
Isolated movements can be caused by catastrophic phenomena (seisms, volcanic eruptions, landslides) in the form of Tsunami S, of solitary waves or Soliton S.
The remainder of the Atlantic Ocean is finally divided between the Northern Atlantic Ocean and the Southern Atlantic Ocean, according to the situation compared to the equator.
In addition to these seas, the following denominations are common:
In addition to these seas, one can also quote:
Sea of Andaman (or Burma)
The remainder of the Pacific Ocean is finally divided between the Northern Pacific Ocean and the Southern Pacific Ocean, according to the situation compared to the equator.
In addition to these seas, one can also quote:
The most obvious example is of course the Mediterranean.
the Baltic (communicates with the North Sea)
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