20 surprising facts about the seas that you may not have known

What are the “most-amazing” seas in Russia? Are there seas on other planets? At what temperature does seawater freeze? Find the answers to these questions and many other nautical questions below.
Which sea has the most states along its coast? Can you drink seawater? What are the “most-most” seas in Russia? Are there seas on other planets? At what temperature does seawater freeze? Look for the answers to these and many other maritime questions below. At the same time you will find out if it is possible to count all the seas, how much gold is in the water of the oceans and why it is still there.

1. Scientists can’t decide how many seas they have: their number varies from 54 to 90. The good thing is that there are only four oceans. There were. Now there are five: the Pacific, the Atlantic, the Indian, the Arctic and the Southern.
2. The boundaries of the seas are a changeable concept. Thus, the Black Sea conquers the land at a rate of about 1 m in 5 years. But the Caspian Sea, which is more often called a lake, is quickly becoming shallower.
3. On the territory of Russia there are several “most-small” seas: the coldest is the East Siberian Sea (-1.8…+5 °C), the smallest are the White Sea (90 000 sq. km) and the Sea of Azov (37 800 sq. km). The latter is also recognized as the shallowest: its depth does not exceed 13.5 m.
4. The Weddell Sea (West Antarctica) is considered the cleanest, and the Mediterranean is the dirtiest, probably because most of the states are located near its shores. According to Greenpeace and the Spanish World Ocean Research Institute, 33 types of waste can be found in every cubic meter of water of the Mediterranean Sea.
5. The Mediterranean Sea is also considered the most “inhabited” – there are about 9 thousand species of living creatures. But the Black Sea, on the contrary, is “inhabited” little and only in the upper layers. At a depth of over 200 meters no one lives there, except bacteria: too much hydrogen sulfide.
6. The Mediterranean Sea and the Sea of Azov used to be land. The first arose as a result of the rising level of the Atlantic Ocean, the second – because of the Black Sea Flood in 5600 BC.
7. The most salty sea – no, not the Dead Sea, because it is a lake, but the Red Sea. One liter of its water has 41 grams of salts.
8. The Red Sea is the only one in which no river flows into it. Because of this, its water is very clear (and very salty, too, largely because of this). It is also the warmest sea.
9. The largest seas are the Sargasso Sea and the Philippine Sea. Sargasso Sea is the largest in terms of area, in addition, it is the only one located right in the middle of the ocean. Philippine Sea – the deepest, it is in its territory is the Mariana Trench depth of more than 10 000 m.
10. If you are going to dive, remember: the shallower the dive depth, the brighter the colors. Red color disappears already at 6 m from the surface, and at a depth of a few tens of meters remain only blue and purple.
11. On the seafloor there are mountains and geysers. There, in the depths, even rivers flow – the water in them has a different density, so it does not mix with the sea.
12. At the bottom of the seas and oceans lies about three million ships! The most dangerous ones are in the Baltic Sea, these are vessels with chemical weapons sunk during the Second World War.
13. Most chemical elements can be found in seawater. Some of them do not go to waste. For example, seawater gives out almost half of all magnesium in the world and quite a lot of bromine. As for gold, there are about 20 million tons of it in the world’s oceans, and most of all – in the waters of the already mentioned Baltic Sea. But it’s not profitable to extract gold from sea water – it’s not worth the effort. But it is possible to dive for treasures.
14. Seawater is used for drinking. However, to do this, it is desalinized beforehand. The procedure is not easy and expensive, but the same Saudi Arabia does not have much choice – they have to drink the Red Sea.
15. In Hong Kong they use seawater in toilet flush systems to save fresh water.
16. Seawater freezes at an average temperature of -1.9°C because of the salts. Zero is enough for fresh water.
17. Sometimes wandering waves, or killer waves, are born in the seas and oceans. This is the name given to waves that arise suddenly and for no apparent reason, they are usually twice as high as the highest waves typical for this part of the water surface. On the peaceful Black Sea, the title of “killer wave” may be a wave with a height of 5 m, in the North Sea, the height of such waves is about 25 m, and in the open ocean – can be off the scale of 100 m! Such waves cause the death of boats and even supertankers.
18. There are seas not only on Earth, but also on other planets. True, they are not really seas. That is, they are not made of water. On Saturn’s moon Titan, the seas of Ligeia and Kraken are made of liquid hydrocarbons. And lunar seas are called basaltic plains of solidified lava.
19. Man is constantly creating new seas – so the people call the reservoirs, emerging usually after the construction of hydroelectric power plants. However, these reservoirs cannot be considered real seas, as they have no connection with the World Ocean, they have completely different characteristics of the bottom and the water is not salty.
20. However, salinity is not such a prerequisite. For example, in 2019, scientists from Columbia University discovered and even mapped a quite fresh sea. Interestingly, it is located under the Atlantic Ocean at a depth of about 183 meters. Perhaps similar seas will be found in other parts of the planet and become the most important reserve of fresh water, which a number of countries greatly lack.