Speaking of the seas, it is necessary to cover the entire hydrosphere as a whole, because water is something without which life on Earth is not just impossible, it would not even have arisen on our planet.
Where did the water come from?
Scientists still have not reached an unequivocal opinion as to where the water came from on Earth. But the most popular and realistic hypothesis today is, according to which an asteroid, which consisted entirely of ice, once fell to Earth. This version looks quite scientific, since in the distant past, our planet was repeatedly subjected to impacts of meteorites and asteroids. It is likely that some of them contained water in the form of ice or a snow-like substance.
Another group of scientists believes that at first the Earth itself looked like a cold meteorite. In the process of ice melting as a result of increased solar activity and changes in the inclination of the earth's axis, seas and oceans began to appear. And since the Sun heats the planet unevenly, the water cycle in nature has begun.
But there are also those who believe that the Earth, on the contrary, was at first like a red-hot ball. Then, when the surface of the planet began to cool, water stood out from under the mantle, like sweat. But all these theories still do not answer the question of how many seas on Earth.
Our planet is unique. It has the largest mass of all such, in addition, the only planet known to man on which there is life. It formed more than 5 billion years ago, attracting the moon, which became the first and only satellite. The seas and oceans of the Earth depend on the lunar cycle. This dependence is visible on the example of ebbs and flows.
When asked how many seas on Earth, in the textbooks they write a number from 76 to 83. There is even evidence that there are only 49, or even 100. If you think about it, this is a lot. But in comparison with the total amount of water on Earth, even with the amount of land - and 76, and 83 of the sea - is negligible. The spread in numbers is obtained because everyone interprets this concept in different ways. Someone considers the seas only the coastal part of the ocean. But in this case, what to do with the inland seas? And with inter-island everything in general becomes incomprehensible. In addition, many seas are now called bays. So the reservoir is not called by hydrogeographic demarcation, but by tradition. For example, everyone knows about the Caspian Sea, although the sea is a huge lake with bitter salty water.
What types of seas are divided into?
- Inter-island . They are often not included in the total number of seas, because they are located between the islands, and not in the coastal zone of the ocean. These include the Fiji, Yavan and Novogvineysk seas .
- Inland seas . As the name implies, they go deep into the land and are connected with the ocean by straits. In this regard, the Sea of Azov near the Crimean Peninsula is unique. It is connected to the ocean not just by straits, but also by other seas - Black and Mediterranean, which also belong to the category of inland seas. The Mediterranean Sea connects to the Atlantic Ocean through the Strait of Gibraltar, Black and Azov - through the Kerch Strait.
- Semi-enclosed . These are seas separated from the ocean by the mainland. These include: the Yellow, Arabian, Aegean, East China, Coral, Andaman, Okhotsk, Caribbean, Japanese, Adriatic, South China Sea and the Baffin Sea.
- Outskirts . They communicate well with the ocean, as they are located just in the coastal continental zone. These include the seas of Ross, Weddell, Laptev, Arafur, Bellingshausen, Timor, Peipsi, Norwegian, Northern, Chukchi, Labrador, Greenland, Kara, East Siberian.
How many seas on the planet are called open? Not so much. These include Sargassovo, Ionian, Tyrrhenian.
Is everything taken into account?
Such a classification, of course, helps to systematize the expanses of water, but complicates the answer to the question of how many seas on planet Earth. Scientists do not always agree with this separation. As a result, outside the attention of researchers are either marginal or open seas, which, in fact, have no coasts. The most famous is the Sargasso Sea, which consists entirely of algae.
Garbage seas
At the moment, in connection with the general deterioration of the ecology of the planet, the question: "How many seas on Earth?" requires a decisive review. For example, scientists distinguish three more, however, they do not consist of water, but of garbage. So, in the Indian and Pacific oceans roam whole floating continents made of plastic and polyethylene. Decaying under the influence of the sun and water, all this floating garbage releases plastic chemical products into the waters of the oceans.
They are disappearing!
But another problem is the disappearance of water resources. For example, the once huge Aral Lake almost disappeared due to human activities. Due to the large water intake from the donor rivers, fresh water ceased to flow into the Aral Lake . As a result, the fauna that inhabited this sea-lake almost completely disappeared.
All of the above shows that the answer to the question of how many seas on Earth has yet to be given.