oceans vs seas

Hej Mai!

What is the difference between a Sea and Ocean? When I lived in Stockholm I lived near the Baltic Sea, and it was only a bit Salty. And the smell was not like the smell in Vancouver. Some people say they are going to the sea, and some people say the ocean. Is there a difference? and If so what makes an ocean different from a sea. How many seas and oceans are there in the world?

TACK!

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Dear Riel,

The main difference between a sea and ocean is size. An ocean is a large body of salt water. Seas are smaller bodies of salt water that are usually situated close to oceans. They can sometimes be considered an ocean as well, such as the Caribbean sea which is also apart of the Atlantic ocean. Seas are partly or fully surrounded by land, like the Caspian or Aral seas.

Ocean beds are also much deeper and only support very basic life forms like bacteria and shrimp mainly because no sunlight reaches the bottom of the ocean . Since seas are close to land and are much shallower it is possible for plant and animal life to thrive.

In the ancient days you often heard about the seven seas. They were the bodies of water that were known about at the time. When they said "seven" they were actually referring to "many" seas. They were the Adriatic, Aegean, Arabian, Black, Caspian, Mediterranean and Red seas.

There are 4 oceans in the world; the Atlantic, Indian, Pacific and Arctic.

There are 108 seas in the world. Some of the main ones are The Bay of Bengal, The Arabian Sea, Red Sea, The Mediterranean Sea, The Baltic Sea, The Black Sea, The Adriatic Sea, The Caspian Sea and the Caribbean Sea.

Most of the salt in the ocean is derived from gradual processes such as the breaking up of the cooled igneous rocks of the Earth's crust by weathering and erosion, the wearing down of mountains, and the dissolving action of rains and streams which transported their mineral washings to the sea. All oceans and seas have different levels of salt and this is called it's "salinity" levels. Different salinity levels can be affected by melting of ice, inflow of river water, evaporation, rain, wind, wave motion and ocean currents.

The saltiest bodies of water in the world are the Dead Sea and the Persian Gulf because of their high evaporation levels. The Dead Sea is so salty that it is hard for marine life to live here hence being called the "Dead" sea.

*Levels of salinity in the worlds oceans and seas. Red is the highest levels.