The Sea of ​​Japan is warm or cold. Water circulation and currents. Water temperature and salinity

Japan - Island state and, therefore, maritime transport plays a huge and important role in the life of the country and its international relations. In total, there are 1020 ports on the territory of the state, differing in the scale of their activities and their direct purpose. Among them are about 100 so-called main ports, 22 main special-purpose ports and 892 local ports. Japan's economy is export-oriented (before the devastating earthquakes, it ranked 3rd in the world in terms of exports) and most of this trade is carried out by sea.

Designation of the largest ports

• Kitakyushu is one of the key ports of the Asian sea routes. The main trade turnover falls on routes to Shanghai, Seoul, Tokyo, Qingdao, Dalian.
• Kobe is one of the largest and key ports in the country, with connections to 500 ports in 120 countries. The largest container terminals are concentrated here. Every year, 83,000 ships from other Japanese ports and 11,000 foreign ships visit here. Kobe is capable of simultaneously receiving 250 large ships.
• Nagoya is a maritime hub focused on international shipping. The annual cargo turnover is 110 million tons.
• Osaka. Main specializations: passenger transport, ferries, container transportation.
• Shimonoseki. The main specialization is trade.
• Tokyo. Passenger and commercial port.

Port of Nagoya

From point of view tourist attraction, we can advise visiting Nagoya Port. One of its parts has been redesigned and converted into an entertainment area, which houses a shopping mall, an amusement park, an aquarium, and the moored icebreaker Fuji used to explore the North Arctic Ocean from the 60s to the 80s of the last century. The Port of Nagoya Public Aquarium, which occupies two buildings, deserves special mention. Here is the largest collection of Japanese marine life, including killer whales, dolphins, beluga and many other inhabitants from the seas surrounding the country.

If we talk directly about the port itself, then it is located in Ise Bay, on the southeast coast of the island of Honshu and is able to simultaneously provide parking for 290 ships with a carrying capacity of up to 65 thousand tons. Nagoya occupies more than 22 square kilometers of water area and is protected by a breakwater 7.6 kilometers long. Ships with industrial equipment, cars and metal products leave from here and ships with iron scrap, oil, timber, grain, wool and cotton arrive. The annual cargo turnover is 119 million tons.

Yokkaichi Port

Iokkaichi is an oil port located on the island of Honshu on the northwestern coast of Ise Bay, 35 kilometers from the port of Nagoya. Crude oil, petrochemical products, automobiles, cotton and wool make up the main cargo turnover. The port has 60 berths from 6.6 - 12 meters, stretching for 6.5 kilometers along the coastline. Yokkaichi is capable of handling tankers with a carrying capacity of up to 300,000 tons.

Port of Tokyo

Located on the western coast of Tokyo Bay. The annual cargo turnover is 72 million tons. The main cargoes are oil, liquefied gas, coal, coal, metals, cement, gravel, paper, cellulose, marine products, salt, flour. There are also several ship repair and shipbuilding enterprises located here, with 4 dry docks and 5 slipways.

Port of Yokohama

The largest port in Japan through which 1/5 of all foreign trade cargo of the country passes. Located on the western coast of Tokyo Bay, 30 kilometers from Tokyo. The dimensions of Yokohama are amazing: the port water area is almost 100 square kilometers and consists of a roadstead, an outer and inner harbor with 166 berths. The length of the mooring front is 40 kilometers, with depths up to 17 meters. The volume of maritime cargo transportation exceeds 130 million tons, which consists of imports of coal, oil products, timber, cement, cotton, seafood and grain, and exports of chemical products, automobiles, metal products and machinery.

In addition to normal activities, the headquarters of the sea transportation of the American military command in the Far East is based in Yokohama. The US military maintains 8 designated berths.

The Sea of ​​Japan is a marginal sea of ​​the Pacific Ocean and is limited by the shores of Japan, Russia and Korea. The Sea of ​​Japan communicates through the Korea Strait in the south with the East China and Yellow Seas, through the Tsugaru (Sangara) Strait in the East with the Pacific Ocean, and through the La Perouse and Tatar Straits in the north with the Sea of ​​Okhotsk. The area of ​​the Sea of ​​Japan is 980,000 km2, average depth 1361 m. The northern boundary of the Sea of ​​Japan runs along 51 ° 45 "N (from Cape Tyk on Sakhalin to Cape Yuzhny on the mainland). The southern boundary goes from Kyushu to the Goto Islands and from there to Korea [Cape Kolcholkap (Izgunov)]

The Sea of ​​Japan has an almost elliptical shape with a major axis in the southwest to northeast direction. Along the coast there are a number of islands or island groups - these are the islands of Iki and Tsushima in the middle part of the Korean Strait. (between Korea and the island of Kyushu), Ulleungdo and Takashima off the east coast of Korea, Oki and Sado off the west coast of the island of Honshu (Hondo) and Tobi Island off the northwestern coast of Honshu (Hondo).

Bottom relief

The straits connecting the Sea of ​​Japan with the marginal seas of the Pacific Ocean are characterized by shallow depths; only the Korea Strait has depths of more than 100 m. Bathymetrically, the Sea of ​​Japan can be divided by 40°N. sh. into two parts: north and south.

The northern part has a relatively flat bottom relief and is characterized by a general smooth slope. The maximum depth (4224 m) is observed in the region of 43°00" N, 137°39" E. d.
The bottom relief of the southern part of the Sea of ​​Japan is quite complex. In addition to the shallow waters around the islands of Iki, Tsushima, Oki, Takashima and Ulleungdo, there are two large isolated
banks separated by deep grooves. This is the Yamato Bank, opened in 1924, in the region of 39°N, 135°E. and the Shunpu Bank (also called the Yamato North Bank), discovered in 1930 and located at about 40 ° N. sh., 134 ° in. e. The smallest depths of the first and second banks are 285 and 435 m, respectively. A depression more than 3000 m deep was found between the Yamato Bank and the island of Honshu.

Hydrological regime

water masses

Sea of ​​Japan can be divided into surface, intermediate and deep. The surface water mass occupies a layer up to approximately 25 m and is separated from the underlying waters in summer by a clearly defined thermocline layer. The surface water mass in the warm sector of the Sea of ​​Japan is formed by mixing surface water high temperature and low salinity, coming from the East China Sea, and coastal waters of the Japan Islands region, in the cold sector - a mixture of waters formed during the melting of ice from early summer to autumn, and the waters of Siberian rivers.

For the surface water mass, the most big fluctuations temperature and salinity depending on the season of the year and area. Thus, in the Korea Strait, the salinity of surface waters in April and May exceeds 35.0 ppm. which is higher than the salinity in the deeper layers, but in August and September the salinity of surface waters drops to 32.5 ppm. At the same time, in the area of ​​the island of Hokkaido, salinity varies only from 33.7 to 34.1 ppm. In summer surface water temperature 25°C, but in winter it varies from 15°C in the Korea Strait to 5°C near the sea. Hokkaido. IN coastal areas in Korea and Primorye, changes in salinity are small (33.7-34 ppm). The intermediate water mass below the surface water in the warm sector of the Sea of ​​Japan has a high temperature and salinity. It is formed in the intermediate layers of Kuroshio west of Kyushu and flows from there into the Sea of ​​Japan from early winter to early summer.

However, according to the distribution of dissolved oxygen, intermediate water can also be observed in the cold sector. In the warm sector, the core of the intermediate water mass is located approximately in the 50 m layer; salinity is about 34.5 ppm. The intermediate water mass is characterized by a rather strong decrease in temperature along the vertical - from 17 ° C at a depth of 25 m to 2 ° C at a depth of 200 m. The thickness of the layer of intermediate water decreases from the warm sector to the cold; in this case, the vertical temperature gradient for the latter becomes much more pronounced. The salinity of intermediate waters is 34.5–34.8 ppm. in the warm sector and about 34.1 prom. in the cold. The highest salinity values ​​are noted here at all depths - from the surface to the bottom.

The deep water mass, commonly referred to as the water of the Sea of ​​Japan itself, has extremely uniform temperature (about 0-0.5 ° C) and salinity (34.0-34.1 ppm). More detailed studies by K. Nishida, however, showed that the temperature of deep waters below 1500 m rises slightly due to adiabatic heating. At the same horizon, a decrease in the oxygen content to a minimum is observed, in connection with which it is more logical to consider waters above 1500 m as deep, and below 1500 m as near-bottom. Compared with the waters of other seas, the oxygen content in the Sea of ​​Japan at the same depths is exceptionally high (5.8–6.0 cm3/l), which indicates an active renewal of water in the deep layers of the Sea of ​​Japan. The deep waters of the Sea of ​​Japan are formed mainly in February and March as a result of the subsidence of surface waters in the northern part of the Sea of ​​Japan due to horizontal diffusion, cooling in winter and subsequent convection, after which their salinity rises to approximately 34.0 ppm.

Sometimes surface waters of low salinity in the cold sector (1-4°C, 33.9 p.m.) wedged into the polar front and deepened to the south, leaving under the intermediate waters of the warm sector. This phenomenon is analogous to the intrusion of subarctic intermediate water below the warm Kuroshio layer in the Pacific Ocean in the region north of Japan.

In spring and summer, the salinity of warm waters from the East China Sea and cold waters east of Korea decreases due to precipitation and ice melt. These less saline waters mix with the surrounding waters and the overall salinity of the surface waters of the Sea of ​​Japan decreases. In addition, these surface waters gradually warm up during the warmer months. As a result, the density of surface waters decreases, which leads to the formation of a well-defined upper thermocline layer separating surface waters from underlying intermediate waters. The layer of the upper thermocline is located in the summer season at a depth of 25 m. In autumn, heat is transferred from the sea surface to the atmosphere. As a result of mixing with the underlying water masses, the temperature of surface waters decreases, and their salinity increases. The emerging intense convection leads to the deepening of the upper thermocline layer to 25–50 m in September and 50–100 m in November. In autumn, the intermediate waters of the warm sector are characterized by a decrease in salinity due to the inflow of waters from the Tsushima Current with lower salinity. At the same time, convection in the surface water layer intensifies during this period. As a result, the thickness of the intermediate water layer decreases. In November, the layer of the upper thermocline disappears completely due to the mixing of the overlying and underlying waters. Therefore, in autumn and spring, only the upper homogeneous layer of water and the underlying cold layer are observed, separated by a layer of the lower thermocline. The latter for most of the warm sector is located at a depth of 200–250, but to the north it rises and near the coast of Hokkaido is located at a depth of about 100 m. In the warm sector of the surface layer, temperatures reach a maximum in mid-August, although in the northern part of the Sea of ​​Japan they spread to the depths. The minimum temperature is observed in February-March. On the other hand, the maximum temperature of the surface layer near the coast of Korea is observed in August. However, due to the strong development of the upper thermocline layer, only a very thin surface layer is heated. Thus, temperature changes in the 50–100 m layer are almost entirely due to advection. Because of low temperatures, characteristic of most of the Sea of ​​Japan at fairly great depths, the waters of the Tsushima Current cool down as they move to the North.

The waters of the Sea of ​​Japan are characterized by exceptionally high levels of dissolved oxygen, partly due to abundant phytoplankton. The oxygen content at almost all horizons is about 6 cm3/l and more. Particularly high oxygen content is observed in surface and intermediate waters, with maximum value at the horizon of 200 m (8 cm3/l). These values ​​are much higher than at the same and lower levels in the Pacific Ocean and the Sea of ​​Okhotsk (1-2 cm3/l).

Surface and intermediate waters are most saturated with oxygen. The saturation percentage in the warm sector is 100% or slightly lower, and the waters near Primorsky Krai and Korea are supersaturated with oxygen due to low temperatures. north coast In Korea, it is 110% and even higher. In deep waters, there is a very high oxygen content to the very bottom.

Color and transparency

The color of the water of the Sea of ​​Japan (according to the color scale) in the warm sector is more blue than in the cold one, corresponding to the region of 36-38 ° N. latitude, 133–136° E e. index III and even II. In the cold sector, this is mainly the color of indices IV-VI, and in the Vladivostok region it is above III. In the northern part of the Sea of ​​Japan, a greenish color of sea water is noted. Transparency (according to the white disk) in the region of the Tsushima current is more than 25 m. In the cold sector, it sometimes drops to 10 m.

Currents of the Sea of ​​Japan

The Tsushima Current, about 200 km wide, washes the coast of Japan and moves further to the NE at a speed of 0.5 to 1.0 knots. Then it is divided into two branches - the warm Sangara current and the warm La Perouse current, which exit respectively into the Pacific Ocean through the Tsugaru (Sangarsky) Strait and into the Sea of ​​Okhotsk through the La Perouse Strait. Both of these currents, after passing through the straits, turn to the east and run respectively near the eastern coast of the island of Honshu and the northern coast of the island of Hokkaido.

Three cold currents are observed in the Sea of ​​Japan: the Liman current, which moves at low speed to the southwest in the area north of Primorsky Krai, the North Korean current, which goes south in the Vladivostok region to eastern Korea, and the Primorskoye, or cold current in the middle part of the Sea of ​​Japan, which originates in the area Tatar Strait and goes to the central part of the Sea of ​​Japan, mainly to the entrance to the Tsugaru (Sangara) Strait. These cold currents form a counterclockwise circulation and in the cold sector of the Sea of ​​Japan contains clearly defined layers of surface and intermediate water masses. Between the warm and cold currents there is a clear boundary of the "polar" front.

Since the Tsushima current contains surface and intermediate water masses, which are about 200 m thick, and is separated from the underlying deep water, the thickness of this current is basically of the same order.

The current velocity to a depth of 25 m is almost constant, and then decreases with depth to 1/6 of the surface value at a depth of 75 m. The flow rate of the Tsushima Current is less than 1/20 of the Kuroshio Current flow rate.

The speed of cold currents is about 0.3 knots for the Liman Current and less than 0.3 knots for the Primorsky Current. The cold North Korea Current, which is the strongest, has a speed of 0.5 knots. This current is 100 km wide and 50 m thick. In general, cold currents in the Sea of ​​Japan are much weaker than warm ones. average speed The Tsushima Current passing through the Korean Strait is smaller in winter, and increases to 1.5 knots in summer (in August). For the Tsushima current, interannual changes are also noted, with a clear period of 7 years being distinguished. The inflow of water into the Sea of ​​Japan mainly occurs through the Korea Strait, since the inflow through the Tatar Strait is very insignificant. The flow of water from the Sea of ​​Japan occurs through the Tsugaru (Sangara) Strait and La Perouse.

Tides and tidal currents

Tidal waves propagate at right angles to these cotidal lines. To the west of Sakhalin and in the area of ​​the Korean Strait. two points of amphidromy are observed. A similar cotidal map can be constructed for the lunisolar diurnal tide. In this case, the point of amphidromy is in the Korea Strait. Since total area Since the cross section of the La Perouse and Tsugaru straits is only 1/8 of the cross section of the Korea Strait, and the cross section of the Tatar Strait is generally insignificant, the tidal wave comes here from the East China Sea mainly through the Eastern Passage (Tsushima Strait). The magnitude of forced fluctuations in the mass of water in the entire Sea of ​​Japan is practically negligible. The resulting component of tidal currents and the Tsushima Current going to the east sometimes reaches 2.8 knots. In the Tsugaru (Soigaru) Strait, a diurnal tidal current prevails, but the magnitude of the semidiurnal tide is greater here.

In tidal currents, diurnal inequality is clearly expressed. The tidal current in the La Perouse Strait is less pronounced due to the difference in levels between the Sea of ​​Okhotsk and the Sea of ​​Japan. There is also a daily disparity here. In the La Perouse Strait, the current is directed mainly to the east; its speed sometimes exceeds 3.5 knots.

Ice Conditions

The melting of ice begins in the areas most distant from the coast. In the second half of March, the Sea of ​​Japan, with the exception of areas close to the coast, is already free of ice. In the northern part of the Sea of ​​Japan, ice off the coast usually melts in mid-April, at which time navigation resumes in Vladivostok. The last ice in the Tatar Strait is observed in early-mid May. The period of ice cover along the coast of Primorsky Krai is 120 days, and at the De-Kastri harbor in the Tatar Strait - 201 days. Along the northern coast of North Korea a large number ice is not observed. Near the western coast of Sakhalin, only the city of Kholmsk is free of ice, since a branch of the Tsushima Current enters this area. The remaining areas of this coast freeze for almost 3 months, during which navigation stops.

Geology

The continental slopes of the Japanese Sea basin are characterized by many submarine canyons. From the side of the mainland, these canyons stretch to depths of more than 2000 m, and from the side of the Japanese islands, only up to 800 m. The Sea of ​​Japan is composed of bedrocks consisting of Precambrian granites and other Paleozoic rocks and overlying igneous and sedimentary rocks of the Neogene. According to paleogeographic studies, the southern part of the modern Sea of ​​Japan, probably in the Paleozoic and Mesozoic and during most of the Paleogene, was dry land. From this it follows that the Sea of ​​Japan was formed during the Neogene and early Quaternary period. The absence of a granite layer in the earth's crust in the northern part of the Sea of ​​Japan indicates the transformation of the granite layer into a basalt layer due to basification, accompanied by the subsidence of the earth's crust. The presence of a "new" oceanic crust here can be explained by the stretching of the continents that accompanies the general expansion of the Earth (Agayed's theory).

Thus, we can conclude that the northern part of the Sea of ​​Japan was once dry land. The present presence of such a large amount of continental material at the bottom of the Sea of ​​Japan at depths of more than 3000 m should indicate that the land was lowered to a depth of 2000–3000 m in the Pleistocene.

The Sea of ​​Japan is currently connected to the Pacific Ocean and the marginal seas surrounding it through the Korean, Tsugaru (Saigarsky), La Perouse and Tatar Straits. However, the formation of these four straits took place in very recent geological periods. The oldest strait is the Tsugaru (Sangara) strait; it already existed during the Wisconsin glaciation, although after that it may have been repeatedly clogged with ice and used in the migration of land animals. The Korea Strait was also dry land at the end of the Tertiary period, and through it the migration of elephants of the southern breed to the Japanese islands was carried out. This strait opened only at the beginning of the Wisconsin glaciation. The La Perouse Strait is the youngest. Fossilized remains of mammoths found on the island of Hokkaido indicate the existence of an isthmus. land on the site of this strait until the end of the Wisconsin glaciation

The extreme south 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 imaginary lines.
In the north, the border between the Sea of ​​Japan and the Sea of ​​Okhotsk runs along the line of Cape Sushcheva - Cape Tyk.
In the Laperouse Strait, the boundary is the line Cape Crillon - 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) - about. Jeju-do is the Korean peninsula.

Within these boundaries, the sea is enclosed between the 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.

Yielding 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, the volume is 1630 thousand km3, the average depth is 1535 m, the greatest depth is 3699 m.
The geographical position and predominantly great depths indicate that the Sea of ​​Japan belongs to the marginal oceanic seas.

There are no major islands. Of the smaller islands, the most significant are: Moneron, Rebun, Rishiri, Okushiri, Oshima, Sado, Okioshima, Ullyndo, Askold, Russian, 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 (Jap. 日本海 nihonkai, Kor. 동해 donghae, "eastern sea") is a sea in the Pacific Ocean, separated from it by the Japanese islands and. By origin, it is a deep-water pseudo-abyssal intrashelf depression connected with other seas and the Pacific Ocean through 4 straits: Korean (Tsushima), Sangar (Tsugaru), La Perouse (Soya), Nevelskoy (Mamiya). It washes the shores of Russia, Japan, the Republic of Korea and the DPRK.
In the south, a branch of the warm current Kuroshio enters.

Cape Bruce Sea of ​​Japan

CLIMATE
The climate is temperate, monsoonal. The northern and western parts of the sea are much colder than the southern and eastern parts. 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 with it warm and humid air. The average air temperature of the warmest month (August) in the northern part is about +15 °C, in the southern regions it is about +25 °C. In autumn, the number of typhoons caused by hurricane-force winds increases. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m.

The salinity of the waters of the Sea of ​​Japan is 33.7–34.3‰, which is somewhat 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 regions. 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 regions: the Tatar Strait, the region 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 is not always formed.
The coldest region is the Tatar Strait, where more than 90% of all ice observed in the sea is formed and localized in the winter season. According to long-term data, the duration of the period with ice in Peter the Great Bay 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 gulfs, closed from the wind, 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, in the tops of Sovetskaya Gavan, Chikhachev and Nevelskoy Straits, primary ice forms are observed already in early November. Early ice formation in Peter the Great Bay (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 development of the ice cover along the coast is faster than near the mainland coast. Accordingly, in the eastern part of the Tatar Strait at this time there is more ice than in the western part. By the end of December, the amount of ice in the eastern and western parts levels off, and after reaching the parallel of Cape Surkum, the direction of the edge changes: its displacement along the Sakhalin coast slows down, and along the mainland it becomes more active.
In the Sea of ​​Japan, the ice cover reaches its maximum development in mid-February. On average, 52% of the area of ​​the Tatar Strait and 56% of the Peter the Great Bay are covered with ice.

The melting of ice begins in the first half of March. In mid-March, the open waters of Peter the Great Bay are cleared of ice and all seaside to Cape Zolotoy. The boundary of the ice cover in the Tatar Strait recedes to the northwest, and in the eastern part of the strait, ice is clearing at this time. Early clearing of the sea from ice occurs in the second decade 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, flora and fauna of temperate latitudes have formed, and in the southern part of the sea, south of Vladivostok, a warm-water faunistic complex prevails. Off the coast of the Far East, a mixture of warm-water and temperate fauna occurs.
Here you can meet octopuses and squids - typical representatives of warm seas. At the same time, vertical walls covered with sea anemones, gardens of brown algae - kelp - all this resembles the landscapes of the White and Barents Seas. Great abundance in the Sea of ​​Japan starfish And sea ​​urchins, of different colors and different sizes, there are brittle stars, shrimps, small crabs (King crabs are found here only in May, and then they go 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, Hyungnam, Chongjin, Busan.

Fishing; extraction of crabs, trepangs, algae, sea urchins; scallop cultivation.

Recreation and tourism
Since the 1990s, off the coast of Primorye, it has been actively developed by local and visiting tourists.
The impetus was such factors as the cancellation or simplification of visiting the border zone, the rise in the cost of passenger transportation around the country, which made the rest of the Far East on the Black Sea coast too expensive, as well as the greatly increased number of personal vehicles, which made the coast of Primorye accessible to residents of Khabarovsk and the Amur region.

Gamow Lighthouse Sea of ​​Japan

Sea naming question
In South Korea it is called the "East Sea" (Korean 동해), and in North Korea it is called the East Sea of ​​Korea (Korean 조선동해). The Korean side claims that the name "Sea of ​​Japan" was imposed on the world community by the Japanese Empire. Japanese side, in turn, shows that the name "Sea of ​​Japan" is found on most maps and is generally accepted.

STRAITS
Korea Strait - the strait between the Korean Peninsula and the islands Japanese archipelago 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 the Tsugaru Strait (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 strait is 18–110 km wide and 96 km long. The depth of the navigable part varies from 110 to 491 m.
There are many good anchorages in the channel, but there are no places completely closed from the wind. The main current is directed from west to east, the speed of the current in the middle of the strait is about 3 knots. The current 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 shores of the island of Hokkaido in the Sangar Strait, the city of Hakodate is located - at the beginning of the 20th 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. Kruzenshtern. From the south side of the strait, Mutsu Bay juts out deep into the land to the south, on which the port city of Aomori is located.
In winter, the strait does not freeze. The Seikan Tunnel passes under the strait - before the commissioning of the Gotthard Base Tunnel, the longest railway tunnel in the world.

The 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.
The length is 94 km, the width in the narrowest part is 43 km, the average depth is 20-40 m, the maximum depth is 118 m. In winter, the strait is covered with ice. It is named after the French navigator Jean Francois de La Perouse, who discovered the strait in 1787.
Wakkanai port is located on the Japanese shore of the strait. In the strait is a rocky island called Danger Stone.
Unlike the normally declared 12-mile (22 km) zone of territorial waters, Japan claims territorial rights in Soya Bay (Sōya) only three nautical miles from the island of Hokkaido (5.5 km). According to Japanese media, 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, Japan's declared nuclear-free status does not violate. Although earlier some ministers have publicly denied that the width of the zone was changed in order to maintain a nuclear-free status.

The Nevelsky Strait is a strait between the mainland of Eurasia and. It 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 after G. I. Nevelsky, who discovered the strait in 1849.
Under the strait during the reign of Stalin it was supposed to build a tunnel.

Petrov Island, Singing Sands Bay

DETAILED GEOGRAPHY AND
Coastline 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 shores of Primorye and the Japanese Islands are most simply in outline, more sinuous. TO major bays mainland coast include: Sovetskaya Gavan, Vladimir, Olga, Peter the Great, Posyet, East Korean; on about. Hokkaido - Ishikari, on about. Honshu - Toyama and Wakasa. The most notable capes are Lazareva, Sandy, Rotary, Gromova, Perish, Tyk, Korsakov, Crillon, Soya, Nosyappu, Tappi, Nyuda and some others.

The coastline is cut by the straits that connect the Sea of ​​Japan with the Pacific Ocean, the Sea of ​​Okhotsk and the East China Sea. The straits are different in length, width and, most importantly, depth, which determines the nature of the water exchange of the Sea of ​​Japan with 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 Korean Strait, divided by the Kojedo, Tsushima and Iki islands 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 at great depths of the sea itself create the 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, Gulf of Vladimir, moonlit night

Diverse in structure and external forms, the coast of the Sea of ​​Japan in different areas belongs to different morphometric types of coasts. From fig. 42 shows that abrasion coasts, mostly slightly altered by the sea, prevail here, although the coasts also have a noticeable length; changed by the activity of the sea. To a lesser extent, the Sea of ​​Japan is characterized by accumulative shores. This sea is surrounded by mostly mountainous shores. In some places, single rocks (kekurs) rise out of the water, characteristic formations of the coast. Low-lying shores are found only in certain parts of the coast.

The distribution of depths 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 trough, gradually narrowing to 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 step is at a depth of 1700–2000 m, and the southern step is 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 approximately at a depth of about 200 m. The surfaces of the northern and middle steps of the central trough are more or less level. The relief of the southern step is significantly complicated big amount separate elevations 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 the vast Vityaz Upland with a minimum depth of 1086 m above it. The steepness of the ledge is on average 10–12°, in some places 25–30°, and the height is about 800–900 m.
The central part of the sea is a deep closed basin, slightly elongated in an east-northeast direction. From the west, north, and east, it is bounded by steep ledges of the slopes of the mountain structures of Primorye, Korea, the islands of Hokkaido and Honshu that go under sea level, and from the south, by the slopes of the Yamato underwater hill.

Dubovaya Bay Sea of ​​Japan

The central part of the sea is characterized by a very weak development of coastal shallows. A relatively wide shoal is observed only in the region of southern Primorye. The edge of the shoal in the central part of the sea is very clearly expressed throughout its 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, separate hills are noted. Approximately in the center of the basin there is an underwater ridge stretched from north to south up to 2300 m high. mountain systems: Kuril-Kamchatka, Japanese and Ryukyu. The central place here is occupied by the vast Yamato Upland, which consists of two ridges elongated in the east-north-east direction with a closed basin located between them. From the south, the Yamato Rise is adjoined by a wide underwater ridge, stretching in a direction close to the 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 continental shelf near Korea is narrow for almost its entire length, its width does not exceed 10 miles. In the area of ​​the Korea Strait, the shallows of Korea and Honshu merge and form shallow water 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 is most pronounced. However, under the influence of various physical and geographical factors, such as the large meridional and small latitudinal strike 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 related meteorological indicators determine the main centers of action of the atmosphere, the location and interaction of which change from season to season. In the cold season (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 northwestern winds with speeds of 12-15 m/s and more dominate the sea. Local conditions change the wind conditions. In some areas, under the influence of the relief of the coasts, a large frequency of northern winds is noted, in others, calms are often observed. On the southeast coast, the regularity of the monsoon is violated, west and northwest winds prevail here.

During the cold season, continental cyclones enter the Sea of ​​Japan. They cause severe 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 over Eastern Siberia in summer. In this regard, south and south-west winds prevail over the sea. However, pressure gradients between areas of high and low pressure are relatively small, so the average wind speed is 2–7 m/s. A significant increase in wind is associated with the release of oceanic, less often continental cyclones to the sea. In summer and early autumn (July-October), the number of typhoons increases over the sea (with a maximum in August-September), which cause hurricane winds. In addition to the summer monsoon, strong and gale-force winds associated with the passage of cyclones and typhoons, winds of local origin are observed in different parts of the sea. They are mainly due to the peculiarities of the orography of the coasts and are most noticeable in the coastal zone.

The summer monsoon brings with it warm and humid air. The average monthly temperature of the warmest month (August) in the northern part of the sea is about 15°, and in the southern regions about 25°. Significant cooling is observed in the northwestern part of the sea with cold air inflows brought by continental cyclones. In spring- summer time cloudy weather prevails with frequent fogs. The monsoonal type of climate, with all its peculiarities (change of winds, weather patterns, etc.), is an essential natural feature of the Sea of ​​Japan.

Sea of ​​Japan, South Korea

Other distinguishing feature of this sea is a relatively small number of rivers flowing into it. The largest of them are Rudnaya, Samarga, Partizanskaya, Tumnin. Almost all of them are mountainous. The continental runoff into the Sea of ​​Japan is approximately 210 km3/year and is fairly evenly distributed over the months. Only in July there is a slight increase in river flow.
The peculiarity of the geographical position, outlines 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 the processes occurring at the water-air interface, the sea annually loses heat. It is replenished due to the heat brought by the 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 heat inflow from outside, in the heat balance of the Sea of ​​Japan.

An important natural factor - the water balance of the sea - consists of the exchange of waters through the straits, the influx of atmospheric precipitation on the sea surface and evaporation from it. The main inflow of water into the Sea of ​​Japan occurs through the Korea Strait - about 97% of the total annual amount of incoming water. The largest flow of water is carried out through the Sangar Strait - 64% of the total flow; 34% flows out through the La Perouse, Nevelskoy and Korean straits. Only about 1% remains for the share of fresh components of the water balance (mainland runoff, precipitation and evaporation). Thus, the main role in the water balance of the sea is played by water exchange through the straits. In the cold season (October to April), the water flow exceeds the income, and from May to September - vice versa. The negative value of the water balance in cold weather is caused by a weakening of the inflow of Pacific waters through the Korea Strait, as well as an increase in runoff through the Laperouse and Sangarsky straits.

Hydrological characteristic.
The impact of the noted factors determines the distribution of temperature, salinity and density of water 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 temperature of the water on 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-pronounced water temperature contrast between the western and eastern parts sea, and in the south it manifests itself weaker than in the north and in the center of the sea. Thus, at the latitude of the Peter the Great Gulf, the water temperature in the west is close to 0°, while in the east it reaches 5–6°. This is explained, in particular, by the advancement of warm waters from south to north along the eastern margin 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. Changes in temperature along latitude are relatively small. Near the western shores, the surface water temperature is 1-2° lower than near the eastern shores, where warm waters spread from south to north.

The vertical temperature distribution 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 the 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°, persists 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 the horizons of 400-500 m, deeper the temperature, decreasing somewhat (to a value of less than 1°), remains approximately the same to the bottom.

Spring warming begins to create vertical temperature differences in the upper layers, which become sharper with time. In summer, in the north and northwest of the sea, a high surface temperature (18–20°) is observed in the 0–10–15 m layer, from here it sharply decreases with depth, reaching 4° at a 50 m horizon, then it decreases 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 rather smoothly with depth, and at a horizon of 200 m it is approximately 6°, from here it decreases somewhat steeper and reaches 1.5–2.0° at horizons of 250–260 m, then it decreases slowly. and at horizons of 750-1500 m, in some areas at horizons of 1000-1500 m, it reaches a minimum equal to 0.04-0.14°, from here the temperature rises to the bottom to values ​​of 0.28-0.26°, and sometimes and up to 0.33°. The formation of an intermediate layer of minimum temperatures is presumably associated with the immersion of chilled harsh winters waters of the northwestern part of the sea. This layer is quite stable and is observed all year round.

The average salinity of the Sea of ​​Japan, which is approximately 34.09‰, is somewhat lower than that in the World Ocean, which is associated with 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 of ice, inflow of continental waters, and other factors, certain features of the distribution of salinity over the seasons 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 freshening is caused by heavy precipitation. In most of the sea, salinity varies from 34.08 to 34.10‰. In the springtime, in the north and northwest, surface water desalination is caused by ice melting, while in other areas it is associated with increased precipitation. Relatively high (34.60–34.70‰) salinity remains in the south, where at this time the inflow of more saline 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 about. 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 here. By autumn, the amount of precipitation decreases, the sea begins to cool, in connection with this, the salinity on the surface increases. Over time, the winter distribution of salinity sets in.
The vertical course of salinity is characterized in general by relatively small, but different from season to season and from place to place, changes in its values ​​in depth. In winter, in most of the sea, a uniform salinity is observed from the surface to the bottom, equal to approximately 34.08–34.10‰ (see Fig. 43, b). Only in coastal waters is a weakly pronounced minimum of salinity in the surface horizons, below which the salinity slightly increases and then remains almost the same to the bottom. At this time of the year, the change in salinity along the vertical in most of the sea does not exceed 0.6–0.7‰, and in its central part it 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, the minimum salinity is observed on the surface as a result of a noticeable desalination of surface waters. In the subsurface layers, salinity increases with depth, and noticeable vertical salinity gradients are created, equal to about 0.03‰ in the north and south and about 0.01‰ in the central part of the sea. The salinity maximum at this time occurs at the 50-100 m horizons in the northern and southern regions and at the 500-1500 m horizons in the south. Below the mentioned layers, salinity decreases somewhat and almost does not change 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 the water in the Sea of ​​Japan depends mainly on temperature. The 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 density on the surface 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 disturbed due to different heating of the upper water layer. In summer, the horizontal differences in the magnitude of surface density are greatest. They are especially significant in the area of ​​mixing of 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 slightly increases at the 50-100 m horizons; deeper, its increase occurs very slightly down to the bottom. The maximum density is observed in March.

Reinecke Island, Peter the Great Bay

In summer, the change in density with depth is rather complex and varies from place to place. In the northwest, the waters are noticeably interlayered in density. It is low 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 noticeably increases in the subsurface (up to 50 m) layers; at horizons of 100–150 m, it is somewhat more uniform; below, the density is quite gradual and slightly increases to the bottom. This transition occurs at the 150–200 m horizons in the northwest and at the 300–400 m horizons in the southeast of the sea.

In autumn, the density begins to level off, which means a transition to a winter type of density distribution with depth. The spring-summer density stratification determines a fairly stable state of the waters of the Sea of ​​Japan, although in different areas it is expressed in varying degrees. In accordance with this, more or less favorable conditions 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 water stratification in the north and northwest of the sea allows wind mixing to penetrate here to horizons of the order of 20 m. In less stratified waters of the southern and south- western regions the wind mixes the upper layers up to horizons of 25-30 m. In autumn, the stability decreases, and the winds intensify, but at this time of the year the thickness of the upper homogeneous layer increases due to density mixing.

Autumn-winter cooling and ice formation in the north 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 covers deeper and deeper layers within a short time. With the onset of ice formation, this process intensifies, and in December the convection penetrates to the bottom. At great depths, it extends to horizons of 2000-3000 m, where it is limited by the deep water of the Sea of ​​Japan. 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 mainly extends to horizons of 200 m. horizons 300-400 m. Below it is limited by the density structure of the waters, and the ventilation of the bottom layers is provided by a combination of turbulence, vertical movements and other dynamic processes.

Peculiarities of the distribution of oceanological characteristics over the area of ​​the sea and with depth, well-developed mixing, inflow of surface waters from adjacent basins and isolation of deep waters from them sea ​​waters 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 (up 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 mass throughout the year. The water of the surface zone, under the influence of climatic and hydrological factors, changes its characteristics in time and space much more intensively.
Three water masses are distinguished in the Sea of ​​Japan: two in the surface zone - the surface Pacific Ocean, 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 the 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 distribution area gradually decrease, and approximately in the region of 48 ° N. sh. due to a sharp decrease in depth, it wedges out in shallow water. In winter, when the Tsushima current weakens, northern border Pacific waters is located approximately at 46-47 ° N. sh.

The surface Pacific water is characterized by high temperatures (about 15–20°) and salinity (34.0–35.5‰). In the considered water mass, several layers are distinguished, the hydrological characteristics of which and the thickness change during the year. The surface layer, where the temperature during 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, whose thickness varies from 50 to 150 m throughout the year, shows significant temperature, salinity and density gradients. The lower layer is 100 to 150 m thick. During the year, the depth of occurrence, the boundaries of its distribution, temperature from 4 to 12 °, salinity from 34.0 to 34.2‰ change. 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 one moves northward, the Pacific Ocean 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 the cooling and freshening of the 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 (about 5–8° on average) 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, 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°C, salinity from 32.0–34.0‰, and the layer thickness 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 inflow of Pacific waters into the sea at this time.

Deep water of the Sea of ​​Japan is formed as a result of the transformation of surface waters sinking to depths due to the process of winter convection due to the general cyclonic circulation. Changes in the characteristics of the deep water of the Sea of ​​Japan along the vertical are extremely small. The bulk of these waters has a temperature of 0.1-0.2° in winter and 0.3-0.5° in summer; salinity during the year is 34.10–34.15‰.
The nature of the circulation of the waters of the sea is determined not only by the influence of the winds acting directly over 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 inflow of Pacific waters depends on this circulation. In summer, the southeast monsoon increases the circulation of the sea waters due to the influx of a large amount of water. In winter, the persistent northwest monsoon prevents water from entering the sea through the Korea Strait, causing a weakening of water circulation. Big influence The bottom topography also influences the circulation of sea waters.

The waters of the western branch of the Kuroshio enter the Sea of ​​Japan through the Korea Strait and spread in a wide stream to the northeast along the Japanese Islands. This stream 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 zone of divergence is formed, which is especially pronounced in summer. Deep water rises in this zone. Having rounded the hills, both branches are connected in the area located to the north-west 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, into the region of the Korean Bay, and passes into a countercurrent along the Korean berets. The removal of the bulk of the Pacific waters from the Sea of ​​Japan occurs through the La Perouse and Sangarsky straits, while part of the waters, reaching the Tatar Strait, give rise to the cold Primorsky Current, moving south. South of the Peter the Great Bay, the Primorskoye Current turns east and merges with the northern branch of the Tsushima Current. An insignificant part of the waters continues to move south to the Korean 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 cycle, the rise of waters is also possible.

In the Sea of ​​Japan, two areas of frontal sections are distinguished. The main polar front is formed by the warm and saline waters of the Tsushima Current and the cold, less saline 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 time the polar front passes somewhat to the south of the 40°N parallel. sh., and near the Japanese Islands the front runs almost parallel to them to the northern tip of about. Hokkaido. In summer, the front is 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, running 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 Korea and Sangara straits, spreads to the northern margins of the sea, and, in combination with its own tide, determines the main features of this phenomenon here. Semidiurnal, diurnal and mixed tides are observed in this sea. In the Korea Strait and in the north of the Tatar Strait - semidiurnal tides, on the eastern coast of Korea, on the coasts of Primorye, the islands of Honshu and Hokkaido - diurnal, in the Peter the Great and Korean bays - mixed.

The nature of the tide corresponds to tidal currents and level fluctuations. In open areas of the sea, semidiurnal tidal currents with velocities of 10–25 cm/s are mainly manifested. The tidal currents in the straits are more complex, where they also have very significant velocities. Thus, in the Sangar Strait, tidal current velocities reach 100–200 cm/s, in the La Perouse Strait, 50–100 cm/s, and 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 does not exceed 1.5 m near Pusan. In the middle part of the sea, the tides are small. Along the eastern coasts of Korea and the Soviet Primorye, 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 due to its funnel-shaped shape.

In addition to tidal waves, 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 sea. In summer (August-September) there is a maximum level rise on all seashores, in winter and early spring (January-April) a minimum level position is observed.

In the Sea of ​​Japan, surge fluctuations in the level are observed. During the winter monsoon, off the western coast of Japan, the level can rise by 20-25 cm, while near the mainland coast, it can drop by the same amount. In summer, on the contrary, off the coast North Korea and Primorye, the level rises by 20-25 cm, while near 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 easterly waves prevail in spring and summer. Most often, there is a wave with a force of 1-3 points, the frequency of which varies from 60 to 80% per year. In winter, strong excitement prevails (6 points or more), the frequency of which is about 10%. In the southeastern part of the sea, due to the stable northwestern monsoon, waves develop from the northwest and north in winter. In summer, weak, most often southwestern 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 waves tsunami.

The northern and northwestern parts of the sea, adjacent to the mainland coast, are annually covered with ice for 4-5 months, the area of ​​\u200b\u200bwhich occupies about a quarter of the space 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 is formed in closed bays and gulfs of the continental coast, for example, in Sovetskaya Gavan Bay, De-Kastri and Olga bays. In October-November, the ice cover mainly develops within the bays and inlets, and from the end of November - the beginning of December, ice begins to form in the open sea. At the end of December, ice formation in the coastal and open areas of the sea extends to Peter the Great Bay. Fast ice in the Sea of ​​Japan is not widespread. First of all, it is formed 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.

Only the northern bays of the mainland coast freeze completely every year. To the 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 immobile 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 West Side 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 significantly weakens, while the role of warm and humid sea masses increases. The ice cover reaches its maximum development around mid-February. From February to May, conditions favorable for the melting of ice (on the spot) are created throughout the sea. In the eastern part of the sea, ice melting begins earlier and is more intense than at the same latitudes in the west. The ice cover of the Sea of ​​Japan experiences significant changes from year to year. There are cases when the ice cover of one winter is twice or more than the ice cover of another.

hydrochemical conditions. The natural features of the Sea of ​​Japan and, above all, the separation 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 biogenic substances over the space of the sea and with depth. In general, the sea is rich in dissolved oxygen. In the western part, its concentration is somewhat higher than in the eastern part, which is explained by the lower water temperature and the relative abundance of phytoplankton in the western regions of the sea. The 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 the intensive vertical water exchange within the sea itself.

Economic use. The Sea of ​​Japan is characterized by the high development of two branches of the national economy: fishery with a wide variety of fishing objects and maritime transport with a developed transportation network. The fishery combines fishing (sardine, mackerel, saury and other species) and the extraction of non-fish objects (sea mollusks - mussels, scallops, squid; algae - kelp, seaweed, anfeltia). " Soviet Union". Although she fishes in the Antarctic, the products are supplied to the fisheries enterprises of Vladivostok. In the Sea of ​​Japan, active work has begun on the cultivation of mariculture - the most promising method of using marine biological resources.

On the coast of the Sea of ​​Japan, in Vladivostok, the Trans-Siberian Railway ends. Here is the most significant transshipment transport hub, where goods are exchanged between rail and sea transport. Further along the Sea of ​​Japan, cargoes go on ships to various foreign and Soviet ports, just as they come from other ports to the ports of the Sea of ​​Japan: Sovetskaya Gavan, Nakhodka, Vanino, Aleksandrovsk-on-Sakhalin, Kholmsk. These ports provide maritime transportation not only in the Sea of ​​Japan, but also beyond. Recently, the ports of Vanino and Kholmsk on Sakhalin have been connected by sea ferry crossing, which 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 in the Far East, but throughout our 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 studies of the Sea of ​​Japan are being carried out and will be carried out with a view to 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. Moscow publishing house. un-ta, 1982.
Japanese Sea. Ministry of Foreign Affairs of Japan.
Wikipedia site.
Magidovich I. P., Magidovich V. I. Essays on history geographical discoveries. - Enlightenment, 1985. - T. 4.
http://www.photosight.ru/
photo: V. Plotnikov, Oleg Slor, A. Marahovets, A. Shpatak, E. Efremov.

The Sea of ​​Japan is considered one of the deepest bodies of water in the world. Its waters spread between Eurasia, Sakhalin and the Japanese Islands. WITH geographic point of view, this area is considered to be a marginal oceanic sea. In Korea, it is customary to call this body of water the East or East Korea Sea.

Shores of the Sea of ​​Japan

The scale of the Sea of ​​Japan is confirmed by its indicators. The total size of the reservoir exceeds 1000 km 2, and the greatest depth reaches almost 4000 meters. The border between the Sea of ​​Japan and the Pacific Ocean is the Japanese Islands, and from the Sea of ​​Okhotsk, the reservoir is fenced off by Sakhalin Island. The Korean Peninsula lies between the Yellow Sea and the Sea of ​​Japan.

The waters of this sea wash the borders of Japan, Korea, North Korea and Russia.

The northern half of the water area freezes during the winter season, but this does not happen in the south due to the heat brought by the Kuroshio Current. The coastline is quite simple and even, especially near Sakhalin. On the territory of the sea there are several small islands, for example, Okushiri, Rebun, Sado. Several mountain rivers also flow into the water area.

Sea of ​​Japan cities

As already mentioned, on the territory of the sea itself there are no major islands, which would have important settlements or ports. The main part of small land areas is located in the eastern waters near the coast. The Russian borders of the Sea of ​​Japan concern Primorsky Krai, the southeastern part Khabarovsk Territory and southwestern regions of Sakhalin. The main ports of the Sea of ​​Japan are:

• Nakhodka;
• Vladivostok;
• Oriental;
• Aleksandrovsk-Sakhalinsky;
• Niigata;
• Tsuruga;
• Wonsan;
• Hyungnam;
• Chongjin;
• Busan.

Fisheries of the Sea of ​​Japan

The waters of this area are considered one of the most saturated in terms of the diversity of fish species. A huge number of fish are caught here throughout the year. Sardines, flounder, mussels, mackerel, tuna, saury, horse mackerel are found here. As for minerals, there are not too many of them. In particular, a gas field was discovered, but no one is developing it. On the coast of the Sea of ​​​​Japan there is a wide transport network, a fishing fleet and quite a few industrial enterprises, because of which the waters are constantly polluted.

Recently, the extraction of kelp, crabs, sea urchins and scallops has been gaining momentum in the Sea of ​​Japan. The tourism industry is also growing.

For centuries, Japan was isolated from the Asian continent. The first to try to cross the Sea of ​​Japan were the ubiquitous Mongols. At the end of the XIII century. Genghis Khan's grandson Khubilai twice tried to take possession of the islands - in 1274 and 1281. Both attempts were unsuccessful. The Mongols were stopped not only by the courage of the Japanese. The first time the attack on the island of Kyushu, the invaders were prevented by a typhoon, and they retreated.

The second time, having thoroughly prepared, the Mongols gathered an army of 100,000 and brought down a fleet of 4,000 ships against the Japanese. But the Sea of ​​Japan hit them with an even more powerful typhoon than the first time. After seven weeks of fighting, a storm swept away and destroyed the entire Mongol fleet.

Otherwise, it could not be interpreted as God's providence. The Japanese called this wind "kamikaze", which means "divine wind".

This is one of the few historical dangers that threatened Japan from outside. Another arose during the Russo-Japanese War. In the waters of the Sea of ​​Japan, not far from the island of Tsushima, in May 1905 a great battle took place, as a result of which the Russian fleet was destroyed.

At the time of " cold war» Both branches of the Korea Strait in the south of the Sea of ​​Japan were under US control. The United States fleet, which wanted to maintain control of the Pacific Ocean, watched the actions of the Soviet fleet in Vladivostok.

Today, only passenger and fishing vessels sail in the peaceful waters of the Sea of ​​Japan.

The surface area of ​​this sea is more than a million square kilometers.

It washes the shores of the Russian Far East, both Korean powers and the island of Japan.

The Sea of ​​Japan is part of the Pacific Ocean, but is separated from it by Sakhalin Island and the Japanese Islands. Through the La Perouse Strait (the Japanese call it Soya) between the islands of Sakhalin and Hokkaido, the Sea of ​​​​Japan is connected with the Sea of ​​Okhotsk, through the Korea Strait - with the East China Sea, and the Sangar Strait between Hokkaido and Honshu connects it with the Pacific Ocean. On Russian coast On the Sea of ​​Japan, Vladivostok is the last point of the Trans-Siberian Railway and an important commercial and military port of Russia.

The greatest depth of the Sea of ​​Japan is 3742 m. In the middle of the basin, the bottom rises and forms the ridges of the Yamato Sea Rise. The minimum depth in this place is 285 m. On the islands of Hokkaido, Honshu and Kyushu there are craters of 36 still active volcanoes, most of them about 3000 m high. This is one of the areas of the highest seismic activity in the world. Earthquakes often occur here, including underwater ones.

Due to strong geological activity, this area is called the Pacific "hot ring".

On the southwestern coast of the Sea of ​​Japan are two Korean states - communist North Korea, isolated from the outside world, and South Korea, which is currently experiencing an economic boom.

The Korea Strait, which separates South Korea from Kyushu, is 180 km wide at its narrowest point, and two currents collide here. Powerful typhoons from the south often besiege Kyushu.

The whole world is in your hands 14-2010

Characteristics of the Sea of ​​Japan

The Sea of ​​Japan lies between the mainland Asia, the peninsula of Korea, about. Sakhalin and the Japanese Islands, separating it from the ocean and two neighboring seas. In the north, the border between the Sea of ​​Japan and the Sea of ​​Okhotsk runs along the line of Cape Sushcheva - Cape Tyk on Sakhalin. In the La Perouse Strait, the line of Cape Soya-m serves as the boundary. Crillon. In the Sangar Strait, the border runs along the line m Syria - m. Estan, and in the Korea Strait - along the line m. Nomo (about Kyushu) - m. Fukae (about Goto) - about. Jeju - Korean Peninsula.

The Sea of ​​Japan is one of the largest and deepest seas in the world. Its area is 1062 km², volume - 1631 thousand km³, average depth -1536 m, maximum depth - 3699 m. This is a marginal oceanic sea.

There are no large islands in the Sea of ​​Japan. Of the smaller ones, the most significant are the islands of Moneron, Risirn, Okushiri, Ojima, Sado, Okinosima, Ullyndo, Askold, Russian, Putyatina. Tsushima Island is located in the Korea Strait. All islands (except Ulleungdo) 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 most simple in outline is the coast of Sakhalin, the coasts of Primorye and the Japanese Islands are more sinuous. Large bays of the mainland coast include De-Kastri, Sovetskaya Gavan, Vladimir, Olyi, Peter the Great Posyet, Korean, on about. Hokkaido - Ishikari, on about. Honshu - Toyama and Wakasa.

Coastal boundaries cut through the straits that connect the Sea of ​​Japan with the Pacific Ocean, the Sea of ​​Okhotsk and the East China Sea. The straits are different in length, width and, most importantly, in depth, which determines the nature of the water exchange in the Sea of ​​Japan. 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, about 400 m. The Nevelskoy and Laperouse straits connect the Sea of ​​Japan and the Sea of ​​Okhotsk. The Korea Strait, divided by the islands of Jejudo, Tsushima and Ikizuki into the western (Broughton Passage with the greatest depth of about 12.5 m) and the eastern (Krusenstern Passage with the greatest depth of about 110 m) parts, connects the Sea of ​​Japan and the East China Sea. Shimonoseki Strait with depths of 2-3 m connects the Sea of ​​Japan with the Inland Sea of ​​Japan. Due to the shallow depths of the straits, at the great depths of the sea itself, conditions are created for isolating its deep waters from the Pacific Ocean and adjacent seas, which is the most important natural feature of the Sea of ​​Japan.

Diverse in structure and external forms, the coast of the Sea of ​​Japan in different areas belongs to different morphometric types of coasts. Mostly these are abrasion, mostly little-changed, coasts. To a lesser extent, the Sea of ​​Japan is characterized by accumulative shores. This sea is surrounded by mostly mountainous shores. In places, single rocks rise out of the water - kekurs - characteristic formations of the Sea of ​​Japan coast. Low-lying shores are found only in certain parts of the coast.

Climate of the Sea of ​​Japan

The Sea of ​​Japan lies entirely in the monsoon climate zone of temperate latitudes. In the cold season (from October to March) it is influenced by the Siberian anticyclone and the Aleutian low, which is associated with significant horizontal atmospheric pressure gradients. In this regard, strong north-western winds with speeds of 12-15 m/s and more dominate the sea. Local conditions change the wind conditions. In some areas, under the influence of the relief of the coasts, a large frequency of northern winds is noted, in others, calms are often observed. On the southeast coast, the regularity of the monsoon is violated, west and northwest winds prevail 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. In early autumn (September), tropical typhoon cyclones sweep over the sea, accompanied by hurricane-force winds.

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 and 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 the southeast.

In warm seasons, the Sea of ​​Japan is subject to the effects of the Hawaiian High and, to a lesser extent, the depression that forms over Eastern Siberia in summer. In this regard, south and south-west winds prevail over the sea. However, pressure gradients between high and low pressure areas are relatively small, so the average wind speed is 2-7 m/s. A significant increase in wind is associated with the release of oceanic, less often continental cyclones to the sea. In summer and early autumn (July-October), the number (with a maximum in September) of typhoons increases over the sea, which cause hurricane-force winds. In addition to the summer monsoon, strong and hurricane winds associated with the passage of cyclones and typhoons, local winds are observed in different parts of the sea. They are mainly due to the peculiarities of the orography of the coasts and are most noticeable in the coastal zone.

The summer monsoon brings with it warm and humid air. The average monthly temperature of the warmest month - August - in the northern part of the sea is about 15 °, and in the southern regions about 25 °. Significant cooling is observed in the northwestern part of the sea with cold air inflows brought by continental cyclones. Cloudy weather with frequent fogs prevails in spring and summer.

A distinctive feature of the Sea of ​​Japan is the relatively small number of rivers flowing into it. The largest of them is Suchan. Almost all rivers are mountainous. The mainland runoff into the Sea of ​​Japan is approximately 210 km³/year and is fairly evenly distributed throughout the year. Only in July the river flow increases slightly

Geographical position, the outlines of the sea basin, 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

The Sea of ​​Japan receives a lot of heat from the sun. However, the total heat consumption for effective radiation and evaporation exceeds the solar heat input, therefore, as a result of the processes occurring at the water-air interface, the sea annually loses heat. It is replenished due to the heat brought by the Pacific waters entering the sea through the straits, therefore, on an average long-term value, the sea is in a state of thermal equilibrium. This indicates the important role of water heat exchange, mainly heat inflow from outside.

Significant natural factors are the exchange of waters through the straits, the flow of precipitation to the sea surface and evaporation. The main inflow of water into the Sea of ​​Japan occurs through the Korea Strait - about 97% of the total annual amount of incoming water. The largest flow of water goes through the Sangar Strait - 64% of the total flow, 34% flows through the La Perouse and Korean Straits. Only about 1% remains for the share of fresh components of the water balance (mainland runoff, precipitation). Thus, the main role in the water balance of the sea is played by water exchange through the straits.

Features of the bottom topography, water exchange through the straits, and climatic conditions form the main features of the hydrological structure of the Sea of ​​Japan. It is similar to the subarctic type of structure of the adjacent regions of the Pacific Ocean, but has its own characteristics, which have developed under the influence of local conditions.

Temperature and salinity of the Sea of ​​Japan

The entire thickness of its waters is divided into two zones, the surface one - up to an average depth of 200 m and the deep one - from 200 m to the bottom. The waters of the deep zone are relatively uniform in physical properties throughout the year. Characteristics of surface water under the influence of climatic and hydrological factors change in time and space much more intensively.

Three water masses are distinguished in the Sea of ​​Japan: two in the surface zone are the surface Pacific Ocean, characteristic of the southeastern part of the sea, and the surface Sea of ​​Japan - for the northwestern part of the sea, and one in the deep part is the deep Sea of ​​Japan water mass.

The surface Pacific water mass is formed by the water of the Tsushima current; it has the largest volume in the south and southeast of the sea. As one moves northward, its thickness and area of ​​distribution gradually decrease, and at about 48° N, 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 about 46-47 ° from latitude.

The surface Pacific water is characterized by high temperatures (about 15-20°) and salinity (34-34.5° / ͚ ). Several layers are distinguished in this water mass, the hydrological characteristics of which and the thickness change throughout the year: during the year it 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 has a thickness varying from 50 to 150 m. Significant gradients of temperature, salinity and density are noted in it, the lower layer has a thickness of 100 to 150 m. Its depth changes throughout the year. occurrence and boundaries of distribution, temperature varies from 4 to 12°, salinity - from 34 to 34.2°/͚ . The lower intermediate layer has very small vertical gradients in temperature, salinity and density. It separates the surface Pacific water mass from the deep Sea of ​​Japan.

As we move north, the characteristics of the Pacific Ocean water gradually change under the influence of climatic factors as a result of its mixing with the underlying deep water of the Sea of ​​Japan. During the cooling and freshening of the Pacific water at latitudes 46-48°N, the surface water mass of the Sea of ​​Japan is formed. It is characterized by relatively low temperature (about 5-8° on average) and salinity (32.5-33.5°/͚ ). The entire thickness of this water mass is divided into three layers, surface, intermediate and deep. As in the Pacific, in the surface Japanese-sea water, the greatest changes in hydrological characteristics occur in the surface layer with a thickness of 10 to 150 m or more. The temperature here during the year varies from 0 to 21°, salinity - from 32 to 34°/͚ . In the intermediate and deep layers, seasonal changes in hydrological characteristics are insignificant

Deep Sea of ​​Japan water is formed as a result of the transformation of surface waters that sink to depths due to the process of winter convection. Changes in the characteristics of the deep water of the Sea of ​​Japan along the vertical are extremely small. The bulk of these waters has a temperature of 0.1-0.2° in winter, 0.3-0.5° in summer, salinity during the year 34.1-34.15°/͚.

The features of the structure of the waters of the Sea of ​​Japan are well illustrated by the distribution of oceanological characteristics in it. Surface water temperature generally increases from northwest to southeast

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. This season is characterized by a well-pronounced water temperature contrast between the western and eastern parts of the sea, and in the south it is less pronounced than in the north and in the central part of the sea. So, 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 influence of warm waters moving from south to north in the eastern part of the sea.

As a result of spring warming, the surface water temperature throughout the sea rises quite rapidly. 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 differences across latitude are relatively small

Near the western shores, the surface water temperature is 1-2° lower than near the eastern shores, where warm waters spread from south to north.

In winter, in the northern and northwestern regions of the sea, the vertical water temperature changes slightly, and its values ​​are close to 0.2-0.4°. In the central, 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 until the horizons of 100-150 m, from which it gradually decreases with depth to about 2-4° at the horizons of 200-250 m, then it decreases very slowly - to 1-1, 5° at the horizons of 400-500 m, deeper the temperature decreases somewhat (to values ​​less than 1°) and remains approximately the same to the bottom.

In summer, in the north and north-west of the sea, high surface temperature (18-20°) is observed in the 0-15 m layer, from here it sharply decreases with a depth of up to 4° at a 50 m horizon, then it decreases very slowly to a horizon of 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 rather smoothly with depth and at a horizon of 200 m it is approximately 6 °, from here it decreases somewhat faster and at the horizons of 250-260 m it is 1.5-2 °, then it decreases very slowly and at horizons 750-1500 m (in some areas at 1000-1500 m horizons) reaches a minimum equal to 0.04-0.14°, from here the temperature rises to the bottom up to 0.3°. The formation of an intermediate layer of minimum temperatures is presumably associated with the subsidence of waters in the northern part of the sea, which are cooled in severe winters. This layer is quite stable and is observed all year round.

The average salinity of the Sea of ​​Japan, which is approximately 34.1°/͚, is somewhat lower than the average salinity of the waters of the World Ocean.

In winter, the highest salinity of the surface layer (about 34.5°/͚ ) is observed in the south. The lowest salinity on the surface (about 33.8°/͚ ) is observed along the southeastern and southwestern coasts, where heavy precipitation causes some freshening. In most of the sea, salinity is 34.1°/͚ . In springtime, in the north and northwest, surface water desalination occurs due to ice melting, while in other areas it is associated with increased precipitation. Relatively high (34.6-34.7°/͚ ) salinity remains in the south, where at this time the inflow of more saline waters flowing through the Korea Strait increases. In summer, the average salinity on the surface varies from 32.5°/͚ in the north of the Tatar Strait to 34.5°/͚ off the coast of the island. Honshu.

In the central and southern regions of the sea, precipitation significantly exceeds evaporation, which leads to desalination of surface waters. By autumn, the amount of precipitation decreases, the sea begins to cool, and therefore the salinity on the surface increases. The vertical course of salinity is generally characterized by small changes in its values ​​with depth. In winter, most of the sea has a uniform salinity from the surface to the bottom, equal to approximately 34.1°/͚ . Only in coastal waters is there a weakly pronounced minimum of salinity in the surface horizons, below which the salinity slightly increases and remains almost the same to the bottom. At this time of the year, vertical salinity changes do not exceed 0.6-0.7°/͚ in most of the sea, and do not reach 0.1°/͚ in its central part.

Spring-summer desalination of surface waters forms the main features of the summer vertical distribution of salinity.

In summer, the minimum salinity is observed on the surface as a result of a noticeable desalination of surface waters. In the subsurface layers, salinity increases with depth, and noticeable vertical salinity gradients are created. The maximum salinity at this time is observed at the horizons of 50-100 m in the northern regions and at the horizons of 500-1500 m in the south. Below these layers, salinity decreases somewhat and almost does not change to the bottom, remaining within 33.9-34.1°/͚. In summer, the salinity of deep waters is 0.1°/͚ less than in winter.

The density of the water in the Sea of ​​Japan depends mainly on temperature. The highest density is observed in winter, and the lowest - in summer. In the northwestern part of the sea, the density is higher than in the southern and southeastern

In winter, the density on the surface is quite uniform throughout the sea, especially in its northwestern part.

In spring, the uniformity of surface density values ​​is disturbed due to different heating of the upper water layer.

In summer, the horizontal differences in surface density values ​​are greatest. They are especially significant in the area of ​​mixing of waters with different characteristics. In winter, the density is approximately the same from the surface to the bottom in the northwestern part of the sea. In the southeastern regions, the density slightly increases at the horizons of 50-100 m, deeper and to the bottom, it increases very slightly. The maximum density is observed in March

In summer, in the northwest, the waters are noticeably stratified in density. It is small on the surface, rises sharply at the horizons of 50-100 m, and deeper to the bottom increases more smoothly. In the southwestern part of the sea, the density noticeably increases in the subsurface (up to 50 m) layers; at the 100-150 m horizons, it is quite uniform; below, the density slightly increases to the bottom. This transition occurs at the 150-200 m horizons in the northwest and at the 300-400 m horizons in the southeast of the sea.

In autumn, the density begins to level off, which means a transition to a winter type of density distribution with depth. The spring-summer density stratification determines a rather stable state of the waters of the Sea of ​​Japan, although it is expressed to different degrees in different regions. In accordance with this, more or less favorable conditions are created in the sea for the emergence and development of mixing.

Due to the predominance of winds of relatively low strength and their significant intensification during the passage of cyclones under conditions of water stratification in the north and northwest of the sea, wind mixing penetrates here to horizons of the order of 20 m. In less stratified waters of the southern and southwestern regions, the wind mixes the upper layers to the horizons 25-30 m. In autumn, the stratification decreases, and the winds intensify, but at this time of the year, the thickness of the upper homogeneous layer increases due to density mixing.

Autumn-winter cooling and ice formation in the north cause intense convection in the Sea of ​​Japan. In its northern and northwestern parts, as a result of rapid autumn cooling of the surface, convective mixing develops, which covers deep layers for a short time. With the onset of ice formation, this process intensifies, and in December the convection penetrates to the bottom. At great depths, it extends to horizons of 2000-3000 m. In the southern and southeastern regions of the sea, which are cooled to a lesser extent in autumn and winter, convection mainly extends to horizons of 200 m. as a result of which density mixing penetrates to horizons of 300-400 m. Below, mixing is limited by the density structure of waters, and ventilation of the bottom layers occurs due to turbulence, vertical movements and other dynamic processes.

The nature of the circulation of the waters of the sea is determined not only by the influence of the winds acting directly over 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 inflow of Pacific waters depends on it. In the summer, the southeast monsoon increases the circulation of water due to the influx of large amounts of water. In winter, the steady northwest monsoon prevents water from entering the sea through the Korea Strait, causing a weakening of water circulation.

The waters of the western branch of the Kuroshio, which passed through the Yellow Sea, enter the Sea of ​​Japan through the Korea Strait and spread to the northeast along the Japanese Islands in a wide stream. This stream is called the Tsushima current. In the central part of the sea, the Yamato Rise divides the flow of Pacific waters into two branches, forming a zone of divergence, which is especially pronounced in summer. In this zone, deep water rises. Having rounded the upland, both branches join in the area located to the 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, into the region of the Korea Strait, and passes into a countercurrent along the coasts of the Korean Peninsula. The bulk of the Pacific waters are carried out of the Sea of ​​Japan through the Sangarsky and La Perouse straits, while part of the waters, having reached the Tatar Strait, give rise to the cold Primorsky current, moving south. South of the Peter the Great Bay, the Primorskoye Current turns east and merges with the northern branch of the Tsushima Current. An insignificant part of the waters continues to move south to the Korean 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, and 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 cycle, the rise of waters is also possible.

Two frontal zones are distinguished in the Sea of ​​Japan - the main polar front formed by the warm and saline waters of the Tsushima Current and the cold, less saline waters of the Primorsky Current, and the secondary front formed by the waters of the Primorsky Current and coastal waters, which have a higher temperature and lower salinity in summer. than the waters of the Primorsky Current. In winter, the polar front passes somewhat south of the 40°N parallel. sh, and near the Japanese Islands it runs approximately parallel to them almost to the northern tip of about. Hokkaido. In summer, the location of the front is approximately the same, it only slightly shifts to the south, and off the coast of Japan - to the west. The secondary front passes near the coast. Primorye, approximately parallel to them.

The tides in the Sea of ​​Japan are quite distinct. They are created mainly by the Pacific tidal wave entering the sea through the Korea and Sangara Straits.

Semidiurnal, diurnal and mixed tides are observed in the sea. In the Korean Strait and in the north of the Tatar Strait - semi-diurnal tides, on the eastern coast of Korea, on the coast of Primorye, near the islands of Honshu and Hokkaido - diurnal, in the Peter the Great and Korean bays - mixed.

Tidal currents correspond to the nature of the tide. In the open areas of the sea, semidiurnal tidal currents with velocities of 10-25 cm/s are mainly manifested. The tidal currents in the straits are more complex, where they also have very significant velocities. So, in the Sangar Strait, tidal currents reach 100-200 cm/s, in the La Perouse Strait - 50-100, in the Korea Strait - 40-60 cm/s.

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 does not exceed 1.5 m.

In the middle part of the sea, the tides are small. Along the eastern shores of the Korean Peninsula and Soviet Primorye, to the entrance to the Tatar Strait, they are no more than 0.5 m. The tides are of the same magnitude near the western shores of Honshu, Hokkaido and Southwestern Sakhalin. In the Tatar Strait, the magnitude of the tides is 2.3-2.8 m. In the northern part of the Tatar Strait, the heights of the tides increase, which is due to its funnel-shaped shape.

In addition to tidal fluctuations in the Sea of ​​Japan, seasonal level fluctuations are well expressed. In summer (August - September) there is a maximum rise in the level on all seashores, in winter and early spring (January - April) there is a minimum level position.

In the Sea of ​​Japan, surge fluctuations in the level are observed. During the winter monsoon, the level can rise by 20-25 cm off the western coast of Japan, and decrease by the same amount near the mainland coast. In summer, on the contrary, off the coast of North Korea and Primorye, the level rises by 20-25 cm, and off the coast of Japan 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 predominate in autumn and winter, while eastern waves prevail in spring and summer. Most often, there is a wave with a force of 1-3 points, the frequency of which varies from 60 to 80% per year. In winter, strong excitement prevails - 6 points or more, the frequency of which is about 10%.

In the southeastern part of the sea, due to the stable northwestern monsoon, waves develop from the northwest and north in winter. In summer, weak, most often southwestern, waves prevail. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m. Tsunami waves are noted in the Sea of ​​Japan.

The northern and northwestern parts of the sea, adjacent to the mainland coast, are annually covered with ice for 4-5 months, the area of ​​\u200b\u200bwhich occupies about 1/4 of the space 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 is formed in closed bays and gulfs of the continental coast, for example, in Sovetskaya Gavan Bay, De-Kastri and Olga bays. In October - November, the ice cover mainly develops within the bays and gulfs, and from the end of November - the beginning of December, ice begins to form in the open sea.

At the end of December, ice formation in the coastal and open areas of the sea extends to Peter the Great Bay.

Fast ice in the Sea of ​​Japan is not widespread. First of all, it forms in the bays of De-Kastri, Sovetskaya Gavan and Olga, in the bays of Peter the Great Bay and Posyet it appears after about a month.

Only the northern bays of the mainland coast freeze completely every year. To the 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 immobile ice appears earlier than in the eastern part, it is more stable. 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 propagating from the mainland. In the east of the sea, the influence of these masses significantly weakens, and at the same time, the role of warm and humid marine air masses increases. The ice cover reaches its maximum development around mid-February. From February to May, conditions are created throughout the sea that favor the melting of ice (on the spot). In the eastern part of the sea, ice melting begins earlier and is more intense than at the same latitudes in the west

The ice cover of the Sea of ​​Japan varies considerably from year to year. There are cases when the ice cover of one winter is 2 times or more higher than the ice cover of another.

The fish population of the Sea of ​​Japan includes 615 species. The main commercial species of the southern part of the sea are sardine, anchovy, mackerel, horse mackerel. In the northern regions, mainly mussels, flounder, herring, greenlings and salmon are mined. Summer in northern part seas penetrate tuna, hammer-fish, saury. Leading place pollack, sardine and anchovy occupy the species composition of fish catches

B.S. Zalogin, A.N. Kosarev "Sea" 1999