What is the difference between an ocean and a sea?

We have all learned at school what are the seas and oceans that border our country: North Sea, English Channel, Atlantic Ocean, Mediterranean Sea. Yet, is the distinction between sea and ocean so clear for all of us? Because, sea or ocean, are only large expanses of salt water! And why do not the North Sea, the Channel and the Atlantic make a single ocean? Come, let’s go and see the blind man!

A question of size!

The first and most obvious distinction is that of size. The five oceans of the globe (Arctic, Atlantic, Austral, Indian and Pacific), have an area much greater than that of the seas. For example, the smallest ocean, the Indian, has an area of ​​about 73 million square kilometers, while the largest sea, that of Arabia, covers “only” 3.6 million square kilometers.

You have to touch the bottom!

The second distinction is based on the seabed. Modern geology is based on the theory of tectonic plates that move relative to each other. Some are underwater and some are continental. Thus the oceans cover oceanic crusts while the seas cover continental crusts.

A third distinction exists, coming from the limits of these stretches of salt water. The oceans are open and communicate widely with each other while the seas are delimited by continents or islands. We can then classify the seas into three groups:

  • Totally enclosed seas such as the Dead Sea or the Caspian Sea;
  • Seas partially open by a strait such as the Mediterranean Sea or the Baltic Sea;

Finally, open seas, delimited in part by continental coasts on one or more sides (the Arabian Sea for example), sometimes by islands or groups of islands (the Caribbean Sea or the Sea of ​​Flores) . There are exceptions, will you say to me? There are always exceptions, but now we are more clear with our geography lessons and leave the exceptions to geographers! You may also visit DifferenceBetweenz to learn the differencebetween more about the such similar terms and objects, which confuses us a lot.