A total of five oceans and seven seas are recognized as of now. Still, suppose we add the smaller seas with these, such as the Barents, Beaufort, Chukchi, Kara, etc. In that case, we will have a total area of the ocean of about 361,000,000 km² which is approx 71% of the earth’s surface. In short, our hydrosphere, which comprises the ocean combined with all freshwater (in groundwater, lakes, rivers, snow, ice & atmosphere), makes up about 0.023% of the Earth's total mass.
Oceans play a crucial role in regulating our climate, weather or even world economy as 90% of the trade is done through sea routes. Therefore, it gets important to learn more about the seas and oceans. The Pacific Ocean is the largest ocean, followed by the Atlantic ocean. And the Indian Ocean is the third largest of all the five and the only ocean named after the country “India”. But how so?
This article discusses the reasoning behind it, the details on all five oceans and seven seas, followed by the difference between a sea and an ocean. So, let’s get started.
Why is the Indian Ocean named after India?
The Indian Ocean spans around 70,560,000 km or 19.8% of the water on Earth's surface, the third-largest oceanic division in the world after the Pacific and the Atlantic oceans. It is restricted to the north by Asia, west by Africa, and east by Australia. However, it even has a border to the south by the Southern Ocean or Antarctica. The shape of this ocean is almost triangular. The Indian Ocean comprises seas (the difference between sea & ocean is explained below) along with its heart, like the Arabian Sea, the Laccadive Sea, the Somali Sea, the Bay of Bengal, and the Andaman Sea.
The Indian Ocean is the only ocean to be named after India. But how did it get its name from a country? India is located at the central point between East and West Asia; that is, India falls in South Asia. Thus, no other country has a long coastline on the Indian Ocean as India has. That’s why it is considered that the name is given for its strategic location at the head of the ocean from ancient times./content-assets/9903c0aee4ec44ac96c46e94a1960871.png)
How many oceans are there in the world?
Of course, only one global ocean covers 71% of the Earth, but this ocean is geographically divided into distinct named regions. It’s just that the boundaries between these regions have evolved with time due to several reasons, such as historical, cultural, geographical & scientific.
There are mainly four oceans: the Atlantic, Pacific, Indian & Arctic. However, most countries, along with the US, have recognized the Southern (Antarctic) as the fifth ocean, wherein the Pacific, Atlantic, and Indian are the most renowned ones. The Southern Ocean, which is the 'newest' named ocean, is recognized by the U.S. Board on Geographic Names.
Difference between sea and ocean
Many people use the terms sea and ocean interchangeably, but both are different; the difference can be seen in geography, where seas are smaller than oceans and are generally situated where the land and ocean meet. Seas are partially enclosed by land (coastline). There is a total of 7 seas and 5 oceans. Let’s read the difference in detail.
Basis
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Sea
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Ocean
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Size
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It is made up of salty water but smaller in size as compared to oceans.
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It is made up of salty water & covers approx 70% of the earth’s surface.
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Area
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The largest sea is the Meditteranean Sea, which is approximately 1.14 million square miles.
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The largest Ocean is the Pacific Ocean, which is approximately 60 million square miles & the smallest ocean is the Arctic Ocean, with an area of 5.4 million square miles.
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Position
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They are generally close to land.
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They are not mandatorily close to land.
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Existence of life
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Aquatic life exists in abundance in seas because it is close to land.
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Oceans have reduced aquatic life as it is far away from the land and deeper than the Seas.
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Depth
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The deepest sea is the Caribbean Sea, with an approx depth of 6900 metres. The Mediterranean, Caribbean, South China, and Black are a few major seas.
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The deepest ocean is the Pacific Ocean which is approx 10,000 metres deep.
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Here's a graphical representation of what a coastline means.
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How many seas are there in the world?
The seven seas recognized by the sailors in Ancient and Medieval Europe are:
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The Mediterranean Sea - This sea is attached to the Atlantic Ocean & several early civilizations developed around it such as Rome, Egypt etc.
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The Adriatic Sea - This is a part of the Mediterranean sea that separates the Italian peninsula from the Balkan peninsula.
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The Black Sea - It is an inland sea between Europe and Asia. It is also connected to the Mediterranean Sea.
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The Red Sea is a narrow strip of water extending south from Northeast Egypt, which connects to the Gulf of Aden and the Arabian Sea. Today, it is connected to the Mediterranean sea via the Suez Canal. Also, it is one of the most travelled waterways in the world.
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The Arabian Sea is located in the northwestern part of the Indian Ocean between India and the Arabian Peninsula (Saudi Arabia). It is a trade route between India and the West.
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The Persian Gulf is a part of the Indian Ocean, located between Iran and the Arabian Peninsula. Its name is not constant and so it is also called the Arabian Gulf, The Gulf, or The Gulf of Iran, but these names are not yet recognized internationally.
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The Caspian Sea - It is situated on the Western edge of Asia and the Eastern edge of Europe. It is basically the largest lake on the planet but as it constitutes saltwater, it is referred to as the sea.
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Note: Apart from these, there are other small seas as well.
However, presently the seven seas recognized today is technically an ocean or section of the ocean by its definition, but still, many geographers accept this list as the actual ” Seven seas":
1) North Atlantic Ocean
2) South Atlantic Ocean
3) North Pacific Ocean
4) South Pacific Ocean
5) Arctic Ocean
6) Southern Ocean
7) Indian Ocean
Interesting Fact
Any water body which ends with the suffix ‘sea’ is not mandatorily a sea like the Caspian Sea & Black sea that are large saltwater lakes. Also, why seven seas & not any other number? The number seven has a different significance. There are seven colours in the rainbow, seven wonders of the world, seven days a week, seven dwarves in Snow White fairy tale movies etc.