And the Japanese islands are the boundaries separating the waters of the Sea of Japan from the Pacific basin. The Sea of Japan predominantly has natural boundaries, only some areas are separated by conventional lines. The Sea of Japan, although it is the smallest of the Far Eastern seas, belongs to the largest. The water surface area is 1062 thousand km2, with a water volume of about 1630 thousand km3. The average depth of the Sea of Japan is 1535 m, the maximum depth is 3699 m. This sea belongs to the marginal oceanic seas.
A small number of rivers carry their waters into the Sea of Japan. The largest rivers are: Rudnaya, Samarga, Partizanskaya and Tumnin. Mostly all of this. During the year it is about 210 km 3 . Throughout the year, fresh water flows evenly into the sea. In July, river flow reaches its maximum. Water exchange between and the Pacific Ocean occurs only in the upper layers.
Japan and the Russian Federation.
Although the reservoir belongs to the ocean basin, it is well isolated from it. This affects both the salinity of the Sea of Japan and its fauna. The overall balance of water is regulated by outflows and inflows through straits. It practically does not participate in water exchange (small contribution: 1%).
It is connected to other bodies of water and the Pacific Ocean by 4 straits (Tsushima, Soyu, Mamaia, Tsugaru). is about 1062 km 2. The average depth of the Sea of Japan is 1753 m, the greatest is 3742 m. It is difficult to freeze, only its northern part is covered with ice in winter.
The hydronym is generally accepted, but is disputed by the Korean powers. They claim that the name was literally imposed by the Japanese side on the whole world. In South Korea it is called the East Sea, while North Korea uses the name Korean East Sea.
The problems of the Sea of Japan are directly related to the environment. They could be called typical, if not for the fact that the reservoir washes several states at once. They have different policies on the sea, so the influence from people also varies. Among the main problems are the following:
- industrial mining;
- release of radioactive substances and oil products;
- oil spills.
Climatic conditions
The Sea of Japan is divided into three parts by glaciation:
- Tatarsky is against;
- Peter the Great Bay;
- area from Cape Povorotny to Belkin.
As already described above, ice is always localized in part of a given strait and bay. In other places it practically does not form (if you do not take into account the bays and northwestern waters).
An interesting fact is that ice initially appears in places where fresh water is present in the Sea of Japan, and only then does it spread to other parts of the reservoir.
Glaciation in the south lasts about 80 days, in the north - 170 days; in the Gulf of Peter the Great - 120 days.
If winter is not characterized by severe frosts, then areas are covered with ice in early to late November; If the temperature drops to critical levels, then freezing occurs earlier.
By February, the formation of the cover stops. At this moment, the Tartary Strait is covered by about 50%, and the Peter the Great Gulf by 55%.
Thaw often begins in March. The depth of the Sea of Japan contributes to the rapid process of getting rid of ice. It may start at the end of April. If the temperature is kept low, then thawing begins in early June. First, parts of the Peter the Great Bay are “opened,” in particular, its open waters, and the coast of the Golden Cape. While the ice in the Tatar Strait begins to retreat, in its eastern part it thaws.
Resources of the Sea of Japan
Biological resources are used by man to the maximum extent. Fishing is developed near the shelf. Valuable fish species are herring, tuna and sardines. In the central regions, squid are caught, in the north and southwest - salmon. The algae of the Sea of Japan also play an important role.
Flora and fauna
The biological resources of the Sea of Japan in different parts have their own characteristic features. Due to the climatic conditions in the north and northwest, nature has moderate characteristics; in the south, the faunal complex predominates. Near the Far East there are plants and animals inhabiting warm-water and temperate climates. Here you can see squid and octopus. In addition to them, there are brown algae, sea urchins, stars, shrimp and crabs. Still, the resources of the Sea of Japan are bursting with diversity. There are few places where you can find red sea squirts. Scallops, ruffs and dogs are common.
Sea problems
The main problem is the consumption of sea resources due to the constant fishing of fish and crabs, algae, scallops, and sea urchins. Along with state fleets, poaching is flourishing. The overuse of fish and shellfish production leads to the constant extinction of some species of marine animals.
In addition, careless fishing can lead to death. Due to fuel and lubricating waste, wastewater and petroleum products, fish die, mutate or become contaminated, which poses a great danger to consumers.
Several years ago, this problem was overcome thanks to coherent actions and agreements between the Russian Federation and Japan.
Ports of companies, enterprises and populated areas are the main source of water pollution containing chlorine, oil, mercury, nitrogen and other hazardous substances. Due to the high concentration of these substances, blue-green algae develop. Because of them, there is a danger of hydrogen sulfide contamination.
tides
Complex tides are characteristic of the Sea of Japan. Their cyclicity differs significantly in different regions. The semi-diurnal one is found near the Korea Strait and near the Tatar Strait. Daytime tides are typical for areas adjacent to the coasts of the Russian Federation, the Republic of Korea and the DPRK, as well as near Hokkaido and Honshu (Japan). Near Peter the Great Bay, the tides are mixed.
Tidal levels are low: from 1 to 3 meters. In some areas the amplitude varies from 2.2 to 2.7 m.
Seasonal variations are also not uncommon. They are observed most often in summer; in winter there are fewer of them. The water level is also affected by the nature of the wind and its strength. Why do the resources of the Sea of Japan depend so much?
Transparency
Throughout the entire length of the sea, the water is of different colors: from blue to blue with a green tint. As a rule, transparency remains at a depth of up to 10 m. The waters of the Sea of Japan have a lot of oxygen, which contributes to the development of resources. Phytoplankton is more common in the north and west of the reservoir. On the surface of the water, the oxygen concentration reaches almost 95%, but this figure gradually decreases with depth, and by 3 thousand meters it is equal to 70%.
Japanese Sea- a marginal sea of the Pacific Ocean, located between the mainland of Eurasia, the Korean Peninsula and the islands of Sakhalin, Hokkaido and Honshu. The countries washed by this sea are Russia, Japan, North Korea and South Korea. The Sea of Japan is one of the largest and deepest seas in the world. Its area is 1062 km 2, volume - 1631 thousand km 3, average depth - 1536 m, greatest depth - 3699 m. This is a marginal oceanic sea. There are no large islands in the Sea of Japan. Of the small ones, the most significant are the islands of Moneron, Rishiri, Okushiri, Ojima, Sado, Okinoshima, Ullyndo, Askold, Russky, and Putyatina. Tsushima Island is located in the Korea Strait. Almost all islands are located near the coast. Most of them are located in the eastern part of the sea. The coastline of the Sea of Japan is comparatively slightly indented. The simplest in outline is the coast of Sakhalin; the coasts of Primorye and the Japanese Islands are more winding.
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Sailing
The study of the Sea of Japan in Russia began (by the detachments of the Great Northern, or Second Kamchatka, expedition of 1733-43) by determining the geographical location of the islands of Japan and Sakhalin and partially photographing their coasts. In 1806, surveys of the eastern coast of the Sea of Japan were carried out by the expedition of I. F. Krusenstern and Yu. F. Lisyansky during their circumnavigation of the world (1803-1806). Of great importance was the discovery in 1849 by G.I. Nevelsky of the strait between the mainland and about. Sakhalin. Since 1880, a permanent Hydrographic Expedition began its work, ensuring the compilation of accurate navigation maps. Simultaneously with hydrographic work, observations of water temperature and surface currents were carried out. Extensive oceanographic work in the Pacific Ocean and Far Eastern seas began in 1888, with the voyage of S. O. Makarov on the corvette Vityaz. Makarov made careful deep-sea observations in the La Perouse Strait for the first time; oceanographers use these data to this day.
During World War II, the study of the sea was sporadic. After the war, especially with the arrival of the special expedition vessel of the Institute of Oceanology of the USSR Academy of Sciences “Vityaz”, research work in the Far Eastern seas reached enormous proportions.
Bottom relief
Based on the nature of the bottom topography, the Sea of Japan is divided into three parts: northern, central and southern. The northern part of the sea is a wide trench, gradually rising and narrowing towards the north. The central part of the sea is a deep closed basin, slightly elongated in the east-northeast direction. The southern part of the sea has a very complex topography with alternating troughs and relatively shallow areas. Here is the vast underwater rise of Yamato.
Climate and hydrological regime
The climate of the Sea of Japan is temperate, monsoonal. The northern and western parts of the sea are much colder than the southern and eastern. In the coldest months (January-February), the average air temperature in the northern part of the sea is about -20 o C, and in the south about +5 o C. The summer monsoon brings with it warm and humid air. The average air temperature of the warmest month (August) in the northern part is approximately +15 o C, in the southern regions about +25 o C. In autumn, the number of typhoons caused by hurricane winds increases. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m.
In winter, the temperature of surface waters from -1 to 0 o C in the north and northwest rises to +10-14 o C in the south and southeast. Spring warming entails a fairly rapid increase in water temperature throughout the sea. In summer, the surface water temperature rises from +18-20 o C in the north to +25-27 o C in the south of the sea. The salinity of the water in the Sea of Japan is 33.7-34.3‰, which is slightly lower than the salinity of the waters of the World Ocean. The tides in the Sea of Japan are distinct, to a greater or lesser extent in different areas. The greatest level fluctuations are observed in the extreme northern and extreme southern regions and reach 3 meters. The appearance of ice in the Sea of Japan is possible as early as October, and the last ice lingers in the north sometimes until mid-June. Every year, only the northern bays of the mainland coast freeze completely. In the western part of the sea, floating, stationary ice appears earlier than in the eastern part, and it is more stable.
Flora and fauna
The Sea of Japan is one of the most productive. Off the coast, algae form powerful thickets; benthos is diverse and large in terms of biomass. The abundance of food and oxygen, the influx of warm waters create favorable conditions for the development of fish fauna. The fish population of the Sea of Japan includes 615 species. Here you can find octopuses and squids - typical representatives of warm seas. At the same time, vertical walls overgrown with sea anemones, gardens of brown algae - kelp - all this is reminiscent of the landscapes of the White and Barents Seas. In the Sea of Japan there is a huge abundance of starfish and sea urchins, of various colors and sizes, brittle stars, shrimps, and small crabs are found (Kamchatka crabs are found here only in May, and then they move further into the sea). Bright red sea squirts live on rocks and stones. Of the mollusks, scallops are the most common. Of the fish, blennies and sea ruffs are often found. In the Sea of Japan you can find fur seals that come here for the winter from more northern regions, representatives of earless seals - seals, dolphins and even whales.
Economic importance
The Sea of Japan is characterized by high development of two industries. Fisheries combine fishing (sardine, mackerel, saury and other species) and the extraction of non-fish objects (sea shellfish - mussels, scallops, squid; algae - kelp, seaweed, ahnfeltia). The leading place in the species composition of fish catches is occupied by pollock, sardine and anchovy. Fishing in most parts of the sea continues all year round. In the Sea of Japan, active work is underway to breed mariculture - the most promising method of using marine biological resources. On the shores of the Sea of Japan, in Vladivostok, the Trans-Siberian Railway ends. The most significant transshipment transport hub is located here, where cargo is exchanged between rail and sea transport. Further along the Sea of Japan, cargo travels on sea vessels to various foreign and Russian ports, just as they arrive from other ports to the ports of the Sea of Japan: Nakhodka, Vanino, Aleksandrovsk-on-Sakhalin, Kholmsk. These ports provide maritime transport not only in the Sea of Japan, but also beyond it. Since the 1990s, the coast of the Sea of Japan off the coast of Primorye has begun to be actively developed by local and visiting tourists. The impetus was factors such as the abolition or simplification of visiting the border zone, the rise in the cost of passenger transportation around the country, which made it too expensive for Far Easterners to vacation on the Black Sea coast, as well as the greatly increased number of personal vehicles, which made the Primorye coast accessible to residents of Khabarovsk and the Amur region.
The resource base of minerals in the Russian part of the Sea of Japan is insignificant. The Izylmetyevskoe gas field was discovered on the West Sakhalin shelf of the sea, but it is unprofitable for exploitation. Promising areas with sand were identified on the continental shores of the sea.
Ecology
The Sea of Japan abounds in flora and fauna suitable for industrial production. Fishing fleets of states are actively fishing and catching crabs, sea cucumbers, algae, sea urchins and scallops. At the same time, there are problems associated with it. The discrepancy between the amount of fish and shellfish caught and the volume of their natural restoration leads to the death and extinction of some of their species. The share of poaching in this is large. In addition, the fleet pollutes sea waters with waste fuels and lubricants, oil products, waste and sewage. This applies not only to fishing vessels, but also to the merchant and military fleets of the four powers. Nuclear fleet bases in the ports of the Sea of Japan, disposal and disposal of used radioactive substances and ships removed from combat duty require close attention and control.
The main source of pollution is the city of Vladivostok. The wastewater from its industrial enterprises, city sewerage, and products from the economic activities of the port and ship repair yards end up in the waters of the Amur and Ussuri Bays, and most of all, in the aquatic environment of the Golden Horn Bay.
The Sea of Japan is characterized by a huge abundance of grasses and algae. In Peter the Great Bay alone, there are more than 200 species of them. These are mainly seaweed and kelp. Sea kale is used for food purposes, which is why it is not only collected in natural areas, but also grown on special plantations. The higher types of herbs include phyllospadix and zoster, which are also numerous in these waters.
The fauna is also very diverse. So, in addition to seals and whales, .
Found in the Sea of Japan and.
The most numerous inhabitants of the Sea of Japan:
Sea anemones
Experienced scuba divers have a wonderful opportunity to admire sea anemones. These are primitive living creatures, close relatives of corals.
Ascidia
While observing the underwater landscape of the bays, you can often find ascidian. Their height is 25 cm.
Shrimps
All kinds of shrimp and crustaceans are found in algae and marine plants at any time of the year. The most famous of them is the grass shrimp. Some of these crustaceans can grow up to 18 cm in length. Juveniles are emerald in color.
Trepangs
Primorsky Krai is famous for its large number of sea cucumbers. There are many of these animals in the Far East and Southeast Asia. They are often called sea ginseng. The habitat of sea cucumbers is rocky placers, boulders and zoster thickets. They feed on microscopic organisms that live on soil particles. Scientists have discovered that the biological active substances secreted by sea cucumbers have antimicrobial and pharmacological effects. Japanese Cucumaria is very similar to sea cucumber. It lives in all Far Eastern seas, but at greater depths than the latter.
Starfish and sea urchins
Species of marine invertebrates include starfish and urchins. Flat urchins are inhabitants of the sandy bottom covered with dark purple hair, while round urchins are the main representatives of the coastal fauna of Primorye. The urchin fishery is extremely developed, as their caviar is a popular delicacy in Asia.
The skeleton of starfish contains calcium carbonate, hence its unusual appearance. In the Sea of Japan there is, for example, the Amur Star, which reaches 32 cm in diameter and moves at a speed of 10 cm per minute. Just like the Patiriya star, which can easily be found in the coastal zone after a storm, the Amur star feeds on sluggish mollusks or mollusks attached to stones.
Oysters, mussels and other shellfish
Adult oysters and mussels lead a sedentary lifestyle. Thanks to special threads, frequent inhabitants of shallow waters - Pacific mussels - are able to stay on the stone even when struck by waves and strong gusts of wind. Only a high level of fertility saves them from complete destruction by mollusks, stars and fish.
Mussels are excellent natural filters and help cleanse coastal waters. But on the other hand, they cause a lot of problems, because... hydraulic structures and ships are overgrown with them. The largest mussels live for about 100 years and grow up to 20 cm in length. Their meat has good taste and contains useful substances. But you should be careful - mussels grown in environmentally unfavorable areas can accumulate microorganisms harmful to humans.
In the desalinated waters of the bays of the Far East of Russia, China, Japan, and Korea, you can find the giant Pacific oyster. It lives at depths up to 7 meters. The size of the shell of this mollusk reaches 70 cm. The giant oyster can withstand both winter under ice and the sun's rays at low tides. At the end of summer in Peter the Great Bay you can see oysters spawning. The female throws out up to 100 million microscopic eggs, which together look like a small cloudy cloud. Then the eggs develop into larvae and float in the water for about a month, being transported over long distances by currents. Then the larvae sink to the bottom in search of a place to live. Having found a suitable underwater object, they firmly attach to it.
Scallop farming in the Sea of Japan is of great industrial importance. This mollusk moves due to the flow of water with a sharp closing of the valves.
Kamchatka crab Kamchatka crab
Another common inhabitant of the local waters is the king crab. It can be found from the Korean Peninsula to the Bering Strait, as well as along the American coast at depths of up to 270m. The span of its claws reaches 150 cm. Kamchatka crab is especially numerous off the coast of Western Kamchatka, where its main fishery is concentrated. The crab feeds mainly on various small mollusks, crustaceans, and worms. In spring, shoals of king crab approach the shores for breeding.
Cephalopods
In the Sea of Japan, there is an active fishery for octopus and squid. One of the largest species of cephalopods, the giant octopus, is also found here. An adult weighs about 50 kg and reaches 3 meters in length (including tentacles). Giant octopuses live mainly in underwater grottoes, under rocks. They can also be found among heaps of stones. Small individuals are caught in the empty shells of large mussels. Octopuses feed on fish, shellfish, and crabs. In case of danger, the octopus releases ink liquid for camouflage and changes its color. They are often found by divers. Octopuses can stick to a suit or to the skin of a scuba diver with their suction cups on their tentacles, but they do not cause much harm to humans.
Fishes of the Sea of Japan
The Primorsky region is famous for its rich variety of fish. About 900 species of fish live in the Sea of Japan. Of these, 179 species are commercial. The permanent inhabitants of these waters are pollock, Far Eastern salmon, cod, flounder, navaga, sea chanterelles, and sculpin gobies. In summer, off the coast of Primorye, you can meet such warm-water fish as mackerel, ivasi herring, saury, anchovy, garfish, half-snouts. Swim in the Sea of Japan and quite exotic species. For example: swordfish, moonfish, pufferfish, saberfish, flying fish, hammerhead shark, red barracuda and hedgehogfish.
Interesting-looking fish are also found among the permanent inhabitants of the seaside waters. In coastal thickets, seahorses, needles, various mollusks, butterfly fish, and cock-bills swim. At the bottom of the sea live bright chanterelles - agonomals, golden ruffs.
12 species of sharks live in the Sea of Japan, the most massive of which is the katran shark. The local sharks are not large and are not dangerous to humans.
Jellyfish
Jellyfish have long been used as food in Thailand, Japan, Korea, Malaysia, Indonesia and the Philippines. Ropilema jellyfish is considered one of the most valuable delicacies. However, to prepare it, you need to spend a lot of time (about a month) and effort. In addition, in China, jellyfish are used in medicine (in the treatment of tracheitis and changes in blood pressure).
Fauna of the Sea of Japan
About 30 species of seals, dolphins and whales live in the Sea of Japan. There is no permanent whaling here. But during the Second World War, minke whales were hunted in Peter the Great Bay. All species of this family are present in the Sea of Japan. Among them: sei whale, blue whale, gray whale, humpback whale, southern right whale, fin whale and minke whale.
In addition, there are many varieties of toothed cetaceans. Among them: sperm whale, white-winged porpoise, northern swimmer, beluga whale, Pacific white-sided dolphin, small killer whale. However, in our time, the number of these animals is less than at the beginning of the twentieth century. The population of minke whales and gray whales has been greatly reduced. At the same time, over the past decades, the number of cetaceans has begun to recover, as intensive whaling has been canceled. Increasingly, one can observe rare species of dolphins and whales off the coast of Primorye and in Peter the Great Bay.
Six species of seals live in the waters of the Sea of Japan. Among them: sea hare, sea lion, northern fur seal, akiba, spotted seal and lionfish.
The southernmost of the Russian Far East lies between the Asian mainland and the Korean peninsula, and the Japanese, separating it from other Pacific seas and the ocean itself.
The Sea of Japan is dominated by natural boundaries, but in some areas it is limited by conventional lines.
In the north, the border between the Sea of Japan and the Sea of Okhotsk runs along the line between Cape Sushchev and Cape Tyk.
In the La Perouse Strait, the border is the line between Cape Crillon and Cape Soya. In the Sangar Strait, the border runs along the line of Cape Syria - Cape Esan, and in the Korea Strait along the line of Cape Nomo (Kyushu Island) - Cape Fukae (Goto Island) - Island. Jeju - Korean Peninsula.
Within these boundaries, the sea is contained between parallels 51°45′ and 34°26′ N. sh. and meridians 127°20′ and 142°15′ E. d.
The configuration is characterized by a large length along the meridian, expansion in the central and southern parts and narrowing in the north.
Second in size to the Bering and Okhotsk Seas, the Sea of Japan is one of the largest and deepest seas in our country. Its area is 1062 thousand km2, volume 1630 thousand km3, average depth 1535 m, greatest depth 3699 m.
The geographical location and predominantly large depths indicate that the Sea of Japan belongs to the marginal oceanic seas.
There are no large islands. Of the small ones, the most significant islands are: Moneron, Rebun, Rishiri, Okushiri, Oshima, Sado, Okioshima, Ullyndo, Askold, Russky, Putyatin. The Tsushima Islands are located in the Korea Strait. All islands, except Ulleungdo, are located near the coast. Most of the islands are located in the eastern part of the sea.
Ezhovaya Bay Sea of Japan 
GENERAL INFORMATION -
The Sea of Japan (Japanese 日本海 nihonkai, cor. 동해 donghae, “eastern sea”) is a sea within the Pacific Ocean, separated from it by the Japanese islands and. By origin, it is a deep-sea pseudo-abyssal intra-shelf depression connected with other seas and the Pacific Ocean through 4 straits: Korean (Tsushima), Sangarsky (Tsugaru), La Perouse (Soya), Nevelsky (Mamiya). It washes the shores of Russia, Japan, the Republic of Korea and the DPRK.
A branch of the warm Kuroshio Current enters in the south.
Cape Bruce Sea of Japan 
CLIMATE
The climate is temperate, monsoon. The northern and western parts of the sea are much colder than the southern and eastern. In the coldest months (January-February), the average air temperature in the northern part of the sea is about −20 °C, and in the south about +5 °C. The summer monsoon brings warm and humid air. The average air temperature of the warmest month (August) in the northern part is approximately +15 °C, in the southern regions about +25 °C. In autumn, the number of typhoons caused by hurricane winds increases. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m.
Currents
Surface currents form a gyre, which consists of the warm Tsushima Current in the east and the cold Primorsky Current in the west. In winter, the temperature of surface waters rises from −1–0 °C in the north and northwest to +10–+14 °C in the south and southeast. Spring warming entails a fairly rapid increase in water temperature throughout the sea. In summer, the surface water temperature rises from 18–20 °C in the north to 25–27 °C in the south of the sea.
The vertical distribution of temperature is not the same in different seasons in different areas of the sea. In summer, in the northern regions of the sea, the temperature is 18–10 °C in a layer of 10–15 m, then it sharply drops to +4 °C at a horizon of 50 m and, starting from a depth of 250 m, the temperature remains constant around +1 °C. In the central and southern parts of the sea, the water temperature decreases quite smoothly with depth and at a horizon of 200 m reaches +6 °C; starting from a depth of 250 m, the temperature remains around 0 °C.
The salinity of the water in the Sea of Japan is 33.7–34.3‰, which is slightly lower than the salinity of the waters of the World Ocean.
Tides in the Sea of Japan are clearly expressed, to a greater or lesser extent in different areas. The greatest level fluctuations are observed in the extreme northern and extreme southern regions. Seasonal fluctuations in sea level occur simultaneously over the entire surface of the sea; the maximum rise in level is observed in summer.
Rudnevo Bay Sea of Japan 
Ice conditions
According to ice conditions, it can be divided into three areas: the Tatar Strait, the area along the coast of Primorye from Cape Povorotny to Cape Belkin and Peter the Great Bay. In winter, ice is constantly observed only in the Tatar Strait and Peter the Great Bay; in the rest of the water area, with the exception of closed bays and bays in the northwestern part of the sea, it does not always form.
The coldest area is the Strait of Tartary, where more than 90% of all ice observed in the sea is formed and localized during the winter season. According to long-term data, the duration of the period with ice in the Peter the Great Gulf is 120 days, and in the Tatar Strait - from 40-80 days in the southern part of the strait, to 140-170 days in its northern part.
The first appearance of ice occurs at the tops of bays and bays, closed from wind and waves and having a desalinated surface layer. In moderate winters in Peter the Great Bay, the first ice forms in the second ten days of November, and in the Tatar Strait, at the tops of Sovetskaya Gavan, Chikhachev Bays and Nevelskoy Strait, primary forms of ice are observed already in early November. Early ice formation in the Peter the Great Gulf (Amur Bay) occurs in early November, in the Tatar Strait - in the second half of October. Later - at the end of November.
In early December, the ice cover develops along the ice faster than near the mainland coast. Accordingly, at this time there is more ice in the eastern part of the Tatar Strait than in the western part. By the end of December, the amount of ice in the eastern and western parts is equalized, and after reaching the parallel of Cape Syurkum, the direction of the edge changes: its displacement along the Sakhalin coast slows down, and along the continental coast it intensifies.
In the Sea of Japan, the ice cover reaches its maximum development in mid-February. On average, ice covers 52% of the area of the Tatar Strait and 56% of the Peter the Great Bay.
Ice melting begins in the first half of March. In mid-March, the open waters of Peter the Great Bay and the entire coastal coast up to Cape Zolotoy are cleared of ice. The ice boundary in the Tatar Strait retreats to the northwest, and in the eastern part of the strait clearing of ice occurs at this time. Early clearing of the sea from ice occurs in the second ten days of April, later - at the end of May - beginning of June.
FLORA AND FAUNA
The underwater world of the northern and southern regions is very different. In the cold northern and northwestern regions, the flora and fauna of temperate latitudes has formed, and in the southern part of the sea, south of Vladivostok, a warm-water faunal complex predominates. Off the coast of the Far East, a mixture of warm-water and temperate fauna occurs.
Here you can find octopuses and squids - typical representatives of warm seas. At the same time, vertical walls overgrown with sea anemones, gardens of brown algae - kelp - all this is reminiscent of the landscapes of the White and Barents Seas. In the Sea of Japan there is a huge abundance of starfish and sea urchins, of various colors and sizes, brittle stars, shrimps, and small crabs are found (Kamchatka crabs are found here only in May, and then they move further into the sea). Bright red sea squirts live on rocks and stones. Of the mollusks, scallops are the most common. Of the fish, blennies and sea ruffs are often found.
Sea transport
Main, Nakhodka, Vostochny, Sovetskaya Gavan, Vanino, Aleksandrovsk-Sakhalinsky, Kholmsk, Niigata, Tsuruga, Maizuru, Wonsan, Hungnam, Chongjin, Busan.
Fishing; production of crabs, sea cucumbers, algae, sea urchin; scallop cultivation.
Recreation and tourism
Since the 1990s, the coast of Primorye has been actively developed by local and visiting tourists.
The impetus was factors such as the abolition or simplification of visiting the border zone, the rise in the cost of passenger transportation around the country, which made it too expensive for Far Easterners to vacation on the Black Sea coast, as well as the greatly increased number of personal vehicles, which made the Primorye coast accessible to residents of Khabarovsk and the Amur region.
Gamow lighthouse Sea of Japan 
The question of naming the sea
In South Korea it is called the “East Sea” (Korean 동해), and in North Korea it is called the Korean East Sea (Korean 조선동해). The Korean side claims that the name “Sea of Japan” was imposed on the world community by the Empire of Japan. The Japanese side, in turn, shows that the name “Sea of Japan” appears on most maps and is generally accepted.
STRAITS
The Korea Strait is a strait between the Korean Peninsula and the islands of the Japanese archipelago of Iki, Kyushu and the southwestern tip of Honshu.
Connects the Sea of Japan and the East China Sea. The length of the strait is 324 km, the smallest width is 180 km, the smallest depth in the fairway is 73 m. Tsushima Island divides the Korea Strait into the Eastern (Tsushima Strait) and Western passages. Japanese Sea 
The Sangar Strait or Tsugaru Strait (Japanese: 津軽海峡 Tsugaru-kaikyo:?) is a strait between the Japanese islands of Honshu and Hokkaido, connecting the Sea of Japan with the Pacific Ocean. The width of the strait is 18-110 km, length - 96 km. The depth of the navigable part varies from 110 to 491 m.
There are many good anchorages in the strait, but there are no places completely sheltered from the wind. The main current is directed from west to east, the current speed in the middle of the strait is about 3 knots. The flow often branches into several separate jets, periodically changing their direction. Tides up to 2 m.
Both banks are mountainous and covered with forest. On the shore of the island of Hokkaido in the Sangar Strait is the city of Hakodate - at the beginning of the twentieth century, the seat of the Russian consulate and the port most visited by Russian Amur ships. The first map of the Sangar Strait was compiled by the Russian admiral I.F. Krusenstern. From the southern side of the strait, Mutsu Bay, on which the port city of Aomori is located, juts deep into the land to the south.
In winter the strait does not freeze. The Seikan Tunnel runs under the strait - before the Gotthard Base Tunnel was put into operation, the longest railway tunnel in the world.
La Perouse Strait is a strait between the northern tip of the island of Hokkaido (Japan) and the southern tip of Cape Crillon (Russian Federation), connecting the Sea of Japan and the Sea of Okhotsk.
Length 94 km, width at the narrowest part 43 km, average depth 20-40 m, maximum depth 118 m. In winter, the strait is covered with ice. Named in honor of the French navigator Jean Francois de La Perouse, who discovered the strait in 1787.
The port of Wakkanai is located on the Japanese shore of the strait. In the strait there is a rocky island called the Stone of Danger.
Unlike the usually declared 12-mile (22 km) zone of territorial waters, Japan claims territorial rights in Sōya Bay only three nautical miles from Hokkaido Island (5.5 km). According to Japanese media reports, this rule has been in effect since the late 1970s to ensure that when US warships and submarines carrying nuclear weapons pass through the straits, there is no violation of Japan’s declared nuclear-free status. Although previously some ministers publicly denied that the width of the zone was changed in order to maintain the nuclear-free status.
The Nevelskoy Strait is a strait between the continent of Eurasia and. Connects the Tatar Strait with the Amur Estuary. The length is about 56 km, the smallest width is 7.3 km, the depth in the fairway is up to 7.2 m.
Named in honor of G.I. Nevelskoy, who discovered the strait in 1849.
During Stalin's reign, it was planned to build a tunnel under the strait.
Petrov Island, Singing Sands Bay 
DETAILED GEOGRAPHY AND
The coastline of the Sea of Japan is relatively weakly indented and does not form bays and bays that protrude deeply into the land, as well as capes that protrude far into the sea. The coasts of Primorye and the Japanese Islands are the simplest in outline. The large bays of the mainland coast include: Sovetskaya Gavan, Vladimir, Olga, Peter the Great, Posyet, East Korean; on o. Hokkaido - Ishikari, on the island. Honshu - Toyama and Wakasa. The most noticeable capes are Lazareva, Peschany, Povorotny, Gromova, Pogibi, Tyk, Korsakova, Krillon, Soya, Nosyappu, Tappi, Nyuda and some others.
The coastline is cut through by straits that connect the Sea of Japan with the Pacific Ocean, the Sea of Okhotsk and the East China Sea. The straits vary in length, width and, most importantly, depth, which determines the nature of water exchange between the Sea of Japan and neighboring basins. Through the Sangar Strait, the Sea of Japan communicates directly with the Pacific Ocean. The depth of the strait in the western part is about 130 m, in the eastern part, where its maximum depths are located, it is about 400 m. The Nevelskoy Strait connects the Sea of Japan and the Sea of Okhotsk. The Korea Strait, divided by the islands of Gojedo, Tsushima and Iki into the western (Broughton Passage with the greatest depth of about 12.6 m) and the eastern (Kruzenshtern Passage with the greatest depth of about 110 m), connects the Sea of Japan and the East China Sea. The Shimonoseki Strait, with depths of about 2-3 m, connects the Sea of Japan and the Inland Sea of Japan. Such shallow depths of the straits with large depths of the sea itself create conditions for its morphometric isolation from the Pacific Ocean and adjacent seas, which is the most important natural feature of the Sea of Japan.
Cape Balyuzek, Vladimir Bay, moonlit night 
The coast of the Sea of Japan, varied in structure and external forms in different areas, belongs to different morphometric types of coasts. From Fig. 42 it is clear that abrasion coasts predominate here, mostly little changed by the sea, although the coasts also have a noticeable extent; modified by sea activity. To a lesser extent, the Sea of Japan is characterized by accumulative shores. This sea is surrounded by predominantly mountainous shores. In some places, single rocks (kekurs), characteristic formations of the coast, rise from the water. Low-lying shores are found only on certain sections of the coast.
The depth distribution in the Sea of Japan is complex and varied. According to the nature of the bottom topography, it is divided into three parts: northern - north of 44 ° N. latitude, central - between 40 and 44° N. sh. and southern - south of 40° N. sh.
The northern part of the sea is like a wide trench, gradually narrowing towards the north. Its bottom in the direction from north to south forms three steps, which are separated from one another by clearly defined ledges. The northern step is located at a depth of 900–1400 m, the middle one at depths of 1700–2000 m, and the southern one at a depth of 2300–2600 m; the surfaces of the steps are slightly inclined to the south. The transition from step to step sharply complicates the bottom topography.
The coastal shoal of Primorye in the northern part of the sea has a width of 10 to 25 miles, the edge of the shoal is located at a depth of about 200 m. The surfaces of the northern and middle stages of the central trench are more or less leveled. The relief of the southern step is significantly complicated by the large number of individual rises located here - up to 500 m above the bottom surface. Here, on the edge of the southern step, at a latitude of 44°, there is a vast Vityaz upland with a minimum depth above it of 1086 m. The southern step of the northern part of the Sea of Japan breaks off with a steep ledge to the bottom of the central basin. The steepness of the ledge is on average 10-12°, in some places 25-30°, and the height is approximately 800-900 m.
The central part of the sea is a deep closed basin, slightly elongated in the east-northeast direction. From the west, north and east, it is limited by steep ledges of the mountain slopes of Primorye, Korea, the islands of Hokkaido and Honshu that go below sea level, and from the south by the slopes of the Yamato underwater rise.
Dubovaya Bay Sea of Japan 
The central part of the sea is characterized by very weak development of coastal shallows. A relatively wide shoal is observed only in the area of southern Primorye. The edge of the shallows in the central part of the sea is very clearly expressed throughout its entire length. The bottom of the basin, located at a depth of about 3500 m, in contrast to the complexly dissected surrounding slopes, is completely leveled. On the surface of this plain there are isolated hills. Approximately in the center of the basin there is an underwater ridge stretching from north to south with a height of up to 2300 m. The southern part of the sea has a very complex topography, since in this area there are the ends of large mountain systems: the Kuril-Kamchatka, the Japanese and the Ryukyu. The central place here is occupied by the vast underwater Yamato Rise, which consists of two ridges elongated in the east-northeast direction with a closed basin located between them. From the south, a wide underwater ridge adjoins the Yamato Rise, stretching in a close meridional direction from the Oki Islands.
In many areas of the southern part of the sea, the structure of the underwater slope is complicated by the presence of underwater ridges. On the underwater slope of Korea, wide underwater valleys can be traced between the ridges. The mainland shelf near Korea is narrow throughout almost its entire length, its width does not exceed 10 miles. In the area of the Korea Strait, the shoals of Korea and Honshu meet and form shallow waters with depths of no more than 150 m.
The Sea of Japan lies entirely in the monsoon climate zone of temperate latitudes. In this sea, the named type of climate manifests itself most clearly. However, under the influence of various physical and geographical factors, for example, the large meridional and small latitudinal extent of the sea, the proximity of the cold Sea of Okhotsk in the north and the warm Pacific Ocean in the south, local features of atmospheric circulation, etc., noticeable climatic differences are formed between different areas of the sea. In particular, the northern and western parts of the sea are colder than the southern and eastern parts; each of them has a certain weather pattern.
Synoptic conditions over the sea and associated meteorological indicators determine the main centers of atmospheric action, the location and interaction of which varies from season to season. In the cold season (from October to March), the sea is influenced by the Siberian anticyclone and the Aleutian low, which creates significant horizontal pressure gradients. In this regard, strong northwest winds with speeds of 12-15 m/s and more dominate over the sea. Local conditions change wind conditions. In some areas, under the influence of coastal topography, there is a high frequency of northern winds, while in others, calms are often observed. On the southeast coast, the regularity of the monsoon is disrupted; western and northwestern winds predominate here.
During the cold season, continental cyclones enter the Sea of Japan. They cause strong storms and sometimes severe hurricanes that last for 2-3 days. At the beginning of autumn (September - October), tropical cyclones - typhoons, accompanied by hurricane winds - sweep over the sea. The winter monsoon brings dry and cold air to the Sea of Japan, the temperature of which increases from south to north and from west to east. In the coldest months (January or February), the average monthly air temperature in the north is about −20°, and in the south about 5°, although significant deviations from these values are often observed. During the cold seasons, the weather is dry and clear in the northwestern part of the sea, wet and cloudy in its southeast.
In warm seasons, the Sea of Japan is affected by the Hawaiian High and, to a lesser extent, by the depression that forms in the summer over Eastern Siberia. In this regard, southern and southwestern winds prevail over the sea. However, pressure gradients between areas of high and low pressure are relatively small, so wind speeds average 2-7 m/s. A significant increase in wind is associated with the entry of oceanic, and less often continental, cyclones into the sea. In summer and early autumn (July - October) the number of typhoons over the sea increases (with a maximum in August - September), which cause hurricane winds. In addition to the summer monsoon, strong and hurricane winds associated with the passage of cyclones and typhoons, winds of local origin are observed in different areas of the sea. They are mainly caused by the peculiarities of coastal orography and are most noticeable in the coastal zone.
The summer monsoon brings warm and humid air. The average monthly temperature of the warmest month (August) in the northern part of the sea is approximately 15°, and in the southern regions about 25°. In the northwestern part of the sea, significant cooling is observed due to the influx of cold air brought by continental cyclones. In spring and summer, cloudy weather with frequent fogs prevails. The monsoon type of climate with all its features (changes in winds, weather patterns, etc.) is an essential natural feature of the Sea of Japan.
Sea of Japan, South Korea 
Another distinctive feature of this sea is the relatively small number of rivers flowing into it. The largest of them are Rudnaya, Samarga, Partizanskaya, Tumnin. Almost all of them have a mountain character. Continental flow into the Sea of Japan is approximately 210 km3/year and is fairly evenly distributed across months. Only in July is there a slight increase in river flow.
The unique geographical location, outline and basin of the sea, separated from the Pacific Ocean and adjacent seas by high thresholds in the straits, pronounced monsoons, water exchange through the straits only in the upper layers are the main factors in the formation of the hydrological conditions of the Sea of Japan.
Located in temperate latitudes, the Sea of Japan receives a large amount of heat from solar radiation. However, the total heat consumption for effective radiation and evaporation exceeds the solar heat input. Consequently, as a result of processes occurring at the water-air interface, the sea loses heat annually. It is replenished by the heat brought by Pacific waters entering the sea through the straits, therefore, on the average long-term value, the sea is in a state of thermal equilibrium. This indicates a very important role of intra-water heat exchange, mainly external heat influx, in the heat balance of the Sea of Japan.
An essential natural factor - the water balance of the sea - consists of the exchange of water through the straits, the flow of atmospheric precipitation onto the sea surface and evaporation from it. The main influx of water into the Sea of Japan occurs through the Korea Strait - about 97% of the total annual amount of incoming water. The largest water flow occurs through the Sangar Strait - 64% of the total flow; 34% flows through the La Perouse, Nevelsky and Korean straits. The share of fresh components of the water balance (continental runoff, precipitation and evaporation) remains only about 1%. Thus, the main role in the water balance of the sea is played by water exchange through the straits. In the cold season (from October to April), water flow exceeds inflow, and from May to September - vice versa. The negative value of the water balance in cold times is caused by a weakening of the flow of Pacific waters through the Korea Strait, as well as an increase in flow through the La Perouse and Sangarsky straits.
Hydrological characteristics.
The impact of the noted factors determines the distribution of temperature, salinity and water density in time and space, the structure and circulation of the waters of the Sea of Japan.
Features of the distribution of water temperature in the sea are formed under the influence of heat exchange with the atmosphere (this factor prevails in the northern and northwestern regions) and water circulation, which prevails in the southern and southeastern parts of the sea. In general, the water temperature at the sea surface rises from the northwest to the southeast, with each season having its own distinctive features.
In winter, the surface water temperature rises from negative values close to 0° in the north and northwest to 10-14° in the south and southeast (Fig. 43). This season is characterized by a well-defined contrast in water temperature between the western and eastern parts of the sea, and in the south it is weaker than in the north and center of the sea. Thus, at the latitude of Peter the Great Bay, the water temperature in the west is close to 0°, and in the east it reaches 5-6°. This is explained, in particular, by the movement of warm waters from south to north along the eastern edge of the sea.
Spring warming entails a fairly rapid increase in surface water temperature throughout the sea. At this time, the temperature differences between the western and eastern parts of the sea begin to smooth out. In summer, the surface water temperature rises from 18-20° in the north to 25-27° in the south of the sea. Temperature changes across latitude are relatively small. On the western shores, the surface water temperature is 1-2° lower than on the eastern shores, where warm waters spread from south to north.
The vertical distribution of temperature is not the same in different seasons in different areas of the Sea of Japan. In winter, in the northern and northwestern regions of the sea, the water temperature changes only slightly from the surface to the bottom. Its values are close to 0.2-0.4°. In the central, especially southern and southeastern parts of the sea, the change in water temperature with depth is more pronounced. In general, the surface temperature, equal to 8-10°, remains up to horizons of 100-150 m, from which it gradually decreases with depth to approximately 2-4° at horizons of 200-250 m, then it decreases very slowly to 1.0-1 .5° at horizons of 400–500 m; deeper, the temperature drops slightly (to a value of less than 1°), remaining approximately the same to the bottom.
Spring warming begins to create vertical temperature differences in the upper layers, which become sharper over time. In summer, in the north and northwest of the sea, high surface temperature (18-20°) is observed in the layer of 0-10-15 m, from here it sharply decreases with depth, reaching 4° at a horizon of 50 m, then its decrease occurs very slowly to the horizon 250 m, where it is approximately 1°, deeper and to the bottom the temperature does not exceed 1°.
In the central and southern parts of the sea, the temperature decreases quite smoothly with depth and at a horizon of 200 m is approximately 6°, from here it decreases somewhat steeper and at horizons of 250–260 m reaches values of 1.5–2.0°, then its decrease occurs slowly and at horizons of 750–1500 m, in some areas at horizons of 1000–1500 m, it reaches a minimum of 0.04–0.14°, from here the temperature rises towards the bottom to values of 0.28–0.26°, and sometimes and up to 0.33°. The formation of an intermediate layer of minimum temperature values is presumably associated with the immersion of the waters of the northwestern part of the sea, cooled during severe winters. This layer is quite stable and is observed all year round.
The average salinity of the Sea of Japan, equal to approximately 34.09‰, is slightly lower than the same value in the World Ocean, which is due to the isolation of the deep waters of the sea from the Pacific Ocean. Under the influence of surface water exchange with adjacent seas and the Pacific Ocean, precipitation, ice formation and melting, influx of continental waters and other factors, certain features of the distribution of salinity by season in different areas of the sea are formed.
In winter, the highest salinity of the surface layer (approximately 34.5‰) is observed in the south, which is explained by the predominance of evaporation over precipitation here (see Fig. 43, b). The lowest salinity on the surface (about 33.8‰) is observed along the southeastern and southwestern coasts of the sea, where some desalination is caused by heavy precipitation. Over most of the sea, salinity varies from 34.08 to 34.10‰. In spring, in the north and northwest, the desalination of surface waters is caused by melting ice, while in other areas it is associated with increased precipitation. Salinity remains relatively high (34.60–34.70‰) in the south, where at this time the influx of saltier waters through the Korea Strait increases.
In summer, the average salinity on the surface varies from 31.5‰ in the north of the Tatar Strait to 34.5‰ off the coast of the island. Honshu, where at this time evaporation prevails over precipitation. In the central and southern regions of the sea, precipitation significantly exceeds evaporation, which causes desalination of surface waters. By autumn, the amount of precipitation decreases, the sea begins to cool, and therefore the salinity on the surface increases. Over time, a winter distribution of salinity occurs.
The vertical course of salinity is generally characterized by relatively small, but different from season to season and from place to place, changes in its values in depth. In winter, over most of the sea, a uniform salinity from surface to bottom is observed, equal to approximately 34.08–34.10‰ (see Fig. 43, b). Only in coastal waters is there a weakly expressed minimum salinity in the surface horizons, below which the salinity increases slightly and then remains almost the same to the bottom. At this time of year, the vertical change in salinity in most of the sea does not exceed 0.6–0.7‰, and in its central part does not reach 0.1‰.
Spring and further desalination of surface waters begins to form the main features of the summer vertical distribution of salinity. In summer, minimal salinity is observed on the surface as a result of noticeable desalination of surface waters. In the subsurface layers, salinity increases with depth, creating noticeable vertical salinity gradients equal to approximately 0.03‰ in the north and south and about 0.01‰ in the central part of the sea. The maximum salinity at this time occurs at horizons of 50–100 m in the northern and southern regions and at horizons of 500–1500 m in the southern regions. Below the mentioned layers, salinity decreases slightly and remains almost unchanged to the bottom, remaining within the range of 33.93–34.13‰. In summer, the salinity of deep waters is 0.1‰ lower than in winter. An increase in surface salinity in autumn begins the transition to the winter vertical distribution of salinity.
The density of water in the Sea of Japan depends mainly on temperature. Density is highest in winter and lowest in summer. In the northwestern part of the sea, the density is always higher than in the southern and southeastern parts. In winter, the surface density is quite uniform throughout the sea, especially in its northwestern part. In the southeastern regions this homogeneity decreases from north to south. In spring, the uniformity of surface density values is disrupted due to different heating of the upper layer of water. In summer, horizontal differences in surface density are greatest. They are especially significant in the area of mixing waters with different characteristics. The vertical distribution of density is characterized in winter by approximately the same values from the surface to the bottom in the northwestern part of the sea. In the southeastern regions, the density increases slightly at horizons of 50-100 m; deeper, its increase occurs very slightly to the bottom. The maximum density is observed in March.
Reineke Island, Peter the Great Bay
In summer, the change in density with depth is quite complex and varies from place to place. In the northwest, the waters are noticeably interlayered in density. It is small on the surface, increases sharply at horizons of 50-100 m, and deeper the density increases more smoothly. In the southwestern part of the sea, the density increases noticeably in the subsurface (up to 50 m) layers; at horizons of 100–150 m it is somewhat more uniform; below, the density is quite smooth and increases slightly to the bottom. This transition occurs at horizons of 150–200 m in the northwest and at horizons of 300–400 m in the southeast of the sea.
In autumn, the density begins to level out, which means a transition to a winter type of density distribution with depth. Spring-summer density stratification determines a fairly stable state of the waters of the Sea of Japan, although it is expressed to varying degrees in different areas. In accordance with this, more or less favorable preconditions are created in the sea for the emergence and development of mixing.
The predominance of winds of relatively low strength and even their significant intensification during the passage of cyclones in conditions of sharp interlayering of waters in the north and northwest of the sea allows wind mixing to penetrate here to horizons of about 20 m. In the less stratified waters of the southern and southwestern regions, the wind mixes the upper layers to horizons of 25-30 m. In autumn, stability decreases and winds increase, but at this time of year the thickness of the upper homogeneous layer increases due to density mixing.
Autumn-winter cooling, and in the north, ice formation, cause intense convection in the Sea of Japan. In the northern and northwestern parts of the sea, the rapid autumn cooling of its surface develops powerful convective mixing, which within a short time covers increasingly deeper layers. With the onset of ice formation, this process intensifies and in December convection penetrates to the bottom. At great depths, it extends to horizons of 2000–3000 m, where it is limited by the deep Sea of Japan water. In the southern and southeastern regions of the sea, cooled in autumn and winter to a lesser extent than the mentioned parts of the sea, convection spreads mainly to horizons of 200 m. In areas of sharp changes in depths, convection is enhanced by the sliding of water along slopes, as a result of which density mixing penetrates up to horizons of 300-400 m. Below it is limited by the density structure of the waters, and ventilation of the bottom layers is ensured by a combination of turbulence, vertical movements and other dynamic processes.
Features of the distribution of oceanological characteristics over the sea area and with depth, well-developed mixing, the influx of surface waters from adjacent basins and the isolation of deep sea waters from them form the main features of the hydrological structure of the Sea of Japan. The entire thickness of its waters is divided into two zones: surface (to an average depth of 200 m) and deep (from 200 m to the bottom). The waters of the deep zone are characterized by relatively uniform physical properties throughout their entire mass throughout the year. Water in the surface zone, under the influence of climatic and hydrological factors, changes its characteristics in time and space much more intensively.
In the Sea of Japan, three water masses are distinguished: two in the surface zone - the surface Pacific, characteristic of the southeastern part of the sea, and the surface Sea of Japan, characteristic of the northwestern part of the sea, and one in the deep zone - the deep Sea of Japan water mass. By their origin, these water masses are the result of the transformation of Pacific waters entering the sea.
The surface Pacific water mass is formed mainly under the influence of the Tsushima Current; it has the largest volume in the south and southeast of the sea. As you move north, its thickness and area of distribution gradually decrease and approximately in the region of 48° N. sh. due to a sharp decrease in depth, it wedges out into shallow water. In winter, when the Tsushima Current weakens, the northern boundary of the Pacific waters is located at approximately 46-47° N. sh.
Surface Pacific water is characterized by high temperatures (about 15-20°) and salinity (34.0-35.5‰). In the water mass under consideration, several layers are distinguished, the hydrological characteristics of which and thickness change throughout the year. The surface layer, where the temperature throughout the year varies from 10 to 25°, and salinity from 33.5 to 34.5‰. The thickness of the surface layer varies from 10 to 100 m. The upper intermediate layer, the thickness of which varies throughout the year from 50 to 150 m. Significant gradients in temperature, salinity and density are noted in it. The lower layer is from 100 to 150 m thick. The depth of occurrence, the boundaries of its distribution, the temperature from 4 to 12°, and the salinity from 34.0 to 34.2‰ change throughout the year. Lower intermediate layer with very slight vertical gradients in temperature, salinity and density. It separates the surface Pacific water mass from the deep Sea of Japan.
winter on the Sea of Japan 
As it moves north, Pacific water gradually changes its characteristics under the influence of climatic factors and due to its mixing with the underlying deep Sea of Japan water. As a result of cooling and desalination of Pacific water at latitudes 46-48° N. sh. The surface water mass of the Sea of Japan is formed. It is characterized by relatively low temperatures (on average about 5-8°) and salinity (32.5-33.5‰). The entire thickness of this water mass is divided into three layers; superficial, intermediate and deep. As in the Pacific Ocean, in the surface water of the Sea of Japan, the greatest changes in hydrological characteristics occur in the surface layer. The temperature here varies throughout the year from 0 to 21°, salinity from 32.0-34.0‰, and the thickness of the layer from 10 to 150 m or more. In the intermediate and deep layers, seasonal changes in hydrological characteristics are insignificant. In winter, the surface water of the Sea of Japan occupies a larger area than in summer, due to the intensive flow of Pacific waters into the sea at this time.
Deep Sea of Japan water is formed as a result of the transformation of surface waters that descend to depths due to the process of winter convection due to the general cyclonic circulation. The vertical changes in the characteristics of the deep Sea of Japan water are extremely small. The bulk of these waters have a temperature of 0.1-0.2° in winter, 0.3-0.5° in summer; salinity throughout the year is 34.10–34.15‰.
The nature of the circulation of sea waters is determined not only by the influence of the winds acting directly above the sea, but also by the circulation of the atmosphere over the northern part of the Pacific Ocean, since the strengthening or weakening of the influx of Pacific waters depends on this circulation. In summer, the southeast monsoon enhances the circulation of sea waters due to the influx of large amounts of water. In winter, the persistent northwest monsoon prevents the flow of water into the sea through the Korea Strait, causing weakening water circulation. The bottom topography also has a great influence on the circulation of sea waters.
Through the Korea Strait, the waters of the western branch of Kuroshio enter the Sea of Japan and spread in a wide stream to the northeast along the Japanese islands. This flow is called the Tsushima Current. As a result of the influence of the bottom topography, in particular the Yamato Rise, in the central part of the sea the flow of Pacific waters is divided into two branches and a divergence zone is formed, which is especially pronounced in the summer. In this zone, deep waters rise. After skirting the hills, both branches join in an area located northwest of the Noto Peninsula.
At a latitude of 38-39°, a small flow separates from the northern branch of the Tsushima Current to the west, in the area of the Korean Bay, and turns into a countercurrent along the berets of Korea. The bulk of Pacific waters are removed from the Sea of Japan through the La Perouse and Sangarsky straits, while some of the waters, having reached the Tatar Strait, give rise to the cold Primorsky Current, moving south. South of Peter the Great Bay, the Primorsky Current turns east and merges with the northern branch of the Tsushima Current. A small part of the water continues to move south to Korea Bay, where it flows into the countercurrent formed by the waters of the Tsushima Current. Thus, moving along the Japanese Islands from south to north, along the coast of Primorye from north to south, the waters of the Sea of Japan form a cyclonic circulation centered in the northwestern part of the sea. In the center of the gyre, rising waters are also possible.
In the Sea of Japan, two areas of frontal sections are distinguished. The main polar front is formed by the warm and salty waters of the Tsushima Current and the cold, less salty waters of the Primorsky Current. The second front is formed by the waters of the Primorsky Current and coastal waters, which in summer have a higher temperature and lower salinity than the waters of the Primorsky Current. In winter, the polar front passes slightly south of the parallel of 40° N. sh., and near the Japanese Islands the front runs almost parallel to them to the northern tip of the island. Hokkaido. In summer, the front is located approximately the same, shifting somewhat to the south, and off the coast of Japan - to the west. The second front is located near the coast of Primorye, passing parallel to them.
The tides in the Sea of Japan are quite distinct. They are created mainly by the Pacific tidal wave. It enters the sea mainly through the Korean and Sangar Straits, spreads to the northern outskirts of the sea and, in combination with its own tide, determines the main features of this phenomenon here. This sea experiences semidiurnal, diurnal and mixed tides. In the Korea Strait and in the north of the Tatar Strait there are semi-diurnal tides, on the eastern coast of Korea, on the coasts of Primorye, the islands of Honshu and Hokkaido - diurnal tides, in the Peter the Great and Korean Gulfs - mixed.
The nature of the tide corresponds to tidal currents and level fluctuations. In open areas of the sea, semidiurnal tidal currents with speeds of 10–25 cm/s are mainly observed. Tidal currents in the straits are more complex, where they have very significant speeds. Thus, in the Sangar Strait, the speed of tidal currents reaches 100-200 cm/s, in the La Perouse Strait - 50-100 cm/s, in the Korean Strait - 40-60 cm/s.
Tidal level fluctuations in different parts of the sea are far from the same. The greatest level fluctuations are observed in the extreme southern and northern regions of the sea. At the southern entrance to the Korea Strait, the tide reaches 3 m. As you move north, it quickly decreases and already at Busan it does not exceed 1.5 m. In the middle part of the sea, the tides are small. Along the eastern coasts of Korea and Soviet Primorye, up to the entrance to the Tatar Strait, they are no more than 0.5 m. The tides are of the same magnitude off the western coasts of Honshu, Hokkaido and. In the Tatar Strait, the magnitude of the tides is 2.3-2.8 m. The increase in the magnitude of the tides in the northern part of the Tatar Strait is determined by its funnel-shaped shape.
In addition to tidal ones, other types of level fluctuations can be traced in the Sea of Japan. In particular, its seasonal fluctuations are well expressed here. They belong to the monsoon type, since the level experiences seasonal changes simultaneously throughout the year throughout the entire sea area. In summer (August–September) the maximum rise in level is observed on all shores of the sea; in winter and early spring (January–April) the minimum level is observed.
In the Sea of Japan, surge level fluctuations are observed. During the winter monsoon off the western coast of Japan, the level can rise by 20-25 cm, and off the mainland coast it can drop by the same amount. In summer, on the contrary, off the coast of North Korea and Primorye the level rises by 20-25 cm, and off the Japanese coast it drops by the same amount.
Strong winds caused by the passage of cyclones and especially typhoons over the sea develop very significant waves, while monsoons cause less strong waves. In the northwestern part of the sea, northwestern waves prevail in autumn and winter, and eastern waves prevail in spring and summer. Most often, disturbances of magnitude 1-3 are observed, the frequency of which varies from 60 to 80% per year. In winter, strong waves prevail (6 points or more), the frequency of which is about 10%. In the southeastern part of the sea, thanks to the stable northwest monsoon, waves from the northwest and north develop in winter. In summer, weak, most often southwesterly waves prevail. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m. Giant tsunami waves have been recorded in the Sea of Japan.
The northern and northwestern parts of the sea, adjacent to the mainland coast, are covered with ice annually for 4-5 months, the area of which occupies about a quarter of the entire sea. The appearance of ice in the Sea of Japan is possible as early as October, and the last ice lingers in the north sometimes until mid-June. Thus, the sea is completely ice-free only during the summer months - July, August and September.
The first ice in the sea forms in closed bays and bays of the mainland coast, for example in Sovetskaya Gavan Bay, De-Kastri and Olga Bays. In October-November, ice cover mainly develops within bays and bays, and from late November to early December, ice begins to form in the open sea. At the end of December, ice formation in coastal and open sea areas extends to Peter the Great Bay. Fast ice is not widespread in the Sea of Japan. It forms first in the bays of De-Kastri, Sovetskaya Gavan and Olga; in the bays of Peter the Great Bay and Posyet, fast ice appears after about a month.
Every year, only the northern bays of the mainland coast freeze completely. South of Sovetskaya Gavan, the fast ice in the bays is unstable and can break up repeatedly during the winter. In the western part of the sea, floating and stationary ice appears earlier than in the eastern part, spreads further to the south and is more stable than at the same latitudes in the eastern part of the sea. This is explained by the fact that the western part of the sea in winter is under the predominant influence of cold and dry air masses spreading from the mainland. In the east of the sea, the influence of these masses weakens significantly, at the same time the role of warm and humid sea masses increases. The ice cover reaches its greatest development around mid-February. From February to May, conditions favorable for ice melting (in situ) are created throughout the sea. In the eastern part of the sea, ice melting begins earlier and occurs more intensely than at the same latitudes in the west. The ice cover in the Sea of Japan experiences significant changes from year to year. There may be cases when the ice cover in one winter is twice or more greater than the ice cover in another.
Hydrochemical conditions. The natural features of the Sea of Japan and, above all, the isolation of the deep part of its basin from the Pacific Ocean form the distinctive features of the hydrochemical conditions in it. They manifest themselves primarily in the distribution of oxygen and nutrients throughout the sea and with depth. In general, the sea is rich in dissolved oxygen. In the western part, its concentration is slightly higher than in the eastern part, which is explained by the lower water temperature and the relative richness of phytoplankton in the western regions of the sea. Oxygen content decreases with depth. However, the Sea of Japan, unlike other seas of the Far East, is characterized by a high oxygen content (up to 69% saturation) in the bottom waters and the absence of an oxygen minimum in the deep layers. This is due to intense vertical water exchange within the sea itself.
Economic use. The Sea of Japan is characterized by the high development of two sectors of the national economy: fishing with a wide variety of fishing objects and maritime transport with a developed transportation network. Fisheries combine fishing (sardine, mackerel, saury and other species) and the extraction of non-fish objects (sea shellfish - mussels, scallops, squid; algae - kelp, seaweed, ahnfeltia). "Soviet Union". Although it fishes in Antarctica, its products go to fisheries enterprises in Vladivostok. In the Sea of Japan, active work has begun on mariculture breeding - the most promising method of using marine biological resources.
On the shores of the Sea of Japan, in Vladivostok, the Trans-Siberian Railway ends. The most significant transshipment transport hub is located here, where cargo is exchanged between rail and sea transport. Further along the Sea of Japan, cargo travels on sea vessels to various foreign and Soviet ports, just as they arrive from other ports to the ports of the Sea of Japan: Sovetskaya Gavan, Nakhodka, Vanino, Aleksandrovsk-on-Sakhalin, Kholmsk. These ports provide maritime transport not only in the Sea of Japan, but also beyond it. Recently, the ports of Vanino and Kholmsk on Sakhalin have been connected by a sea ferry, which has further strengthened the transport role of the Sea of Japan.
Research in the Sea of Japan has been carried out since ancient times, so it is one of the most studied seas not only of the Far East, but of our entire country. Nevertheless, there are still many unresolved problems in all oceanological aspects. With regard to hydrological problems, the most significant are: the study of the quantitative characteristics of water exchange through the straits, the formation of thermohaline conditions in the deep layers of the sea, vertical movements of water, patterns of ice drift; development of forecasts for the passage of typhoons and tsunamis. All these are just examples of the main directions in which research in the Sea of Japan is being and will be carried out with the aim of its further development.
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SOURCE OF INFORMATION AND PHOTO:
Team Nomads
http://tapemark.narod.ru/more/18.html
Melnikov A.V. Geographical names of the Russian Far East: Toponymic Dictionary. — Blagoveshchensk: Interra-Plus (Interra+), 2009. — 55 p.
Sovetov S.A., Sea of Japan // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional). - St. Petersburg, 1890-1907.
Shamraev Yu. I., Shishkina L. A. Oceanology. L.: Gidrometeoizdat, 1980.
The Sea of Japan in the book: A. D. Dobrovolsky, B. S. Zalogin. Seas of the USSR. Publishing house Moscow. University, 1982.
Japanese Sea. Ministry of Foreign Affairs of Japan.
Wikipedia website.
Magidovich I. P., Magidovich V. I. Essays on the history of geographical discoveries. - Enlightenment, 1985. - T. 4.
http://www.photosight.ru/
photo: V. Plotnikov, Oleg Slor, A. Marakhovets, A. Shpatak, E. Efremov.
