Difference between Sea and Ocean

Sea and ocean are two different water bodies of saline water but people often use these two terms interchangeably while referring to a large body of saline water. We do agree that sea and ocean share a number of features but still, they are different from each other in terms of their area, depth and marine flora and fauna. Let us see how they differ from each other so that next time we do not confuse these giant water bodies with each other!

Sea:

A sea is a water body of saline water. It is a part of the ocean and is partially enclosed by the land, i.e. it is located at the margins of an ocean, where it connects the ocean with the land. For example, the Bering Sea is the part of the Pacific Ocean and connects it with the land.

As seas are parts of the oceans they are smaller in size than the oceans. The top five largest seas in terms of their area are as follows:

  • Philippine Sea: It is a part of the North Pacific Ocean and covers an area of around 5, 177,000 sq. km.
  • Arabian Sea: It is a part of the Indian Ocean and covers an area of around 3,862,000 sq. km.
  • South China Sea: It is a part of the Pacific Ocean with an area of 3,600,000 sq. km.
  • Caribbean Sea: It is a part of the Atlantic Ocean with an area of 2,754,000 sq. km.
  • Mediterranean Sea: It is a part of the Atlantic Ocean and covers an area of around 2,515,000 sq. km.

Ocean:

Oceans are vast and continuous water bodies of salt water that cover more than 70 % of the total Earth's surface. All the oceans on the surface of Earth are interconnected and are considered as one World Ocean. This "World Ocean" is divided into five different oceans which are listed below in terms of their area, starting from the largest ocean to the smallest ocean.

  • Pacific Ocean: 166,266,877 sq. km.
  • Atlantic Ocean: 76,762,000 sq. km.
  • Indian Ocean: 68,566,000 sq. km.
  • Southern Ocean: 52,646, 688 sq. km.
  • Arctic Ocean: 13,208, 939 sq. km.

Based on the above information, some of the key differences between sea and ocean are as follows:

SeaOcean
It is a large body of saline water that is smaller in size than ocean.It is a massive water body of saline water that is much larger in size than the sea.
It is less deep than the ocean.It is much deeper than the sea.
Seas are close to the land so they have more diverse marine life than oceans.Oceans are far away from the land so they have less diverse marine flora and fauna than seas.
Seas support the marine life at sea beds as the sunlight can easily penetrate deeper into the sea and reach sea beds to allow photosynthesis to support the marine life.Oceans are much deeper so sunlight cannot reach the ocean beds and thus photosynthesis does not take place to support the marine life.
All seas are not interconnected with one another.All oceans are interconnected with one another.
It is partially surrounded by land as it connects the ocean with the land.It is not surrounded by land.




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