Is the difference between sea and ocean just a matter of surface? That’s the question we’re going to answer for you.
Planet Earth, also called the blue planet, has 70% of its surface covered by oceans. And on our planet Earth, there are four significant oceans that every schoolchild learns about: the Atlantic Ocean, the Pacific Ocean, the Indian Ocean, and the Arctic Ocean. The latter ocean is primarily occupied by ice.
But what exactly defines an ocean, and what is the difference between a sea and an ocean? We’ll explain.
Oceans, open seas and enclosed seas – There are five oceans on our planet Earth:
the Pacific Ocean
the Atlantic Ocean
the Indian Ocean
the Arctic Ocean
the Southern Ocean
There are three main categories of seas. The first concerns the open seas, that is, the seas that are directly connected to the oceans. They are also called “marginal seas”:
the Mediterranean Sea
the Red Sea
the Baltic Sea
the Black Sea
the Caribbean Sea
The second type of sea concerns the closed or enclosed seas :
the Caspian Sea
the Aral Sea
the Dead Sea
And finally, the third type of sea concerns the seas that are an integral part of the oceans. These are open seas with a larger surface area of water: the Yellow Sea in the Pacific Ocean and the North Sea in the Atlantic Ocean.
The most crucial criterion for differentiation: size.
If you open the Petit Robert (the French equivalent of the Duden), the definition of the sea of the ocean is the same: “large expanse of salt water covering a large part of the earth’s surface.” Nevertheless, there are differences between these bodies of water.
Geographers think that this is only a question of the surface. The oceans are large areas of salt water, while the seas are smaller. According to Futura Sciences, the sea is smaller but not closed.
Take, for example, the Mediterranean Sea, which is open to the Atlantic Ocean at the Strait of Gibraltar. This is not the only example, of course. The Baltic Sea, the Black Sea, and the Red Sea are seas that are connected to the oceans. Some waters are closed and, therefore, not connected to the oceans. This is the case with three seas: the Caspian, Aral, and Dead Sea.
The oceans and seas are defined by conventions that people have decided. It is necessary to know that the term “ocean” became official only at the end of the 19th century. Magellan sailed across the Pacific Ocean and called it that when the weather was calm.
The word sea comes from Latin: mare and maris. The term ocean comes from the Greek Ôkeanos, a sea deity symbolizing the water surrounding the Earth’s disk. So, according to people’s definition, an ocean refers to a large area of saltwater bounded by continents.
Continents bound oceans
It is not only a history of size that distinguishes a sea from an ocean. The type of coasts, the depth of the ocean floor, and the salinity (salt water) are also essential factors.