Sea of ​​Japan characteristic. areas of Primorsky Krai. Which islands are located in the Sea of ​​Japan

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 extent 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, volume is 1630 thousand km3, average depth 1535 m, maximum depth 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 associated with other seas and Pacific Ocean through 4 straits: Korean (Tsushima), Sangarsky (Tsugaru), La Perouse (Soya), Nevelsky (Mamiya). It washes the shores of Russia, Japan, the Republic of Korea and the DPRK.
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. average temperature air of the warmest month (August) in the northern part is approximately +15 ° C, in southern regions 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 period ice is constantly observed only in the Tatar Strait and the Gulf of Peter the Great, in the rest of the water area, with the exception of closed bays and gulfs 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 Far East there is a mixture of warm-water and temperate fauna.
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 passenger traffic across the country, which made the rest of the Far East on Black Sea coast, as well as a 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" (Kor. 동해), and in the North - the East Sea of ​​Korea (Kor. 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
The Korea Strait is a strait between the Korean Peninsula and the islands of the 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.
Length 94 km, width in the narrowest part 43 km, average depth 20-40 m, maximum depth 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
The coastline of the Sea of ​​Japan is comparatively weakly indented and does not form bays and coves protruding deeply into the land, as well as capes protruding far into the sea. The most simple in outline are the more sinuous coasts of Primorye and Japanese islands. 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 small depths of the straits at great depths The sea itself creates 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 a vast Vityaz upland with minimum depth above it is 1086 m. The southern step of the northern part of the Sea of ​​Japan breaks off in a steep ledge to the bottom of the central basin. The steepness of the ledge is on average 10–12°, in some places 25–30°, and the height is 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 elongated from north to south with a height of up to 2300 m. The southern part of the sea has a very complex relief, since the ends of large mountain systems are located in this area: the Kuril-Kamchatka, Japanese and Ryukyu. Central location 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 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 coast, there is a high frequency of northern winds, 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, 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 (with a maximum in August-September) of typhoons increases over the sea, which cause hurricane-force 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. 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.
originality geographical location, 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 southern and southeastern parts 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 the transition to winter look 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, the northern boundary of the Pacific waters is located at about 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 Ocean, in the surface water of the Sea of ​​Japan, the greatest changes in hydrological characteristics occur in 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 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 winds acting directly over the sea, but also by the circulation of the atmosphere over northern part 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 number water. In winter, the persistent northwest monsoon prevents water from entering the sea through the Korea Strait, causing a weakening of water circulation. The bottom topography also has a great influence on the circulation of the 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. So, in the Sangar Strait of speed tidal currents reach 100-200 cm/s, in the La Perouse Strait - 50-100 cm/s, in the Korean - 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, and in Japanese shores decreases 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, in autumn and winter, northwestern waves prevail, and in spring and summer - eastern directions. 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. IN Lately the ports of Vanino and Kholmsk on Sakhalin are 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. place names Far East of Russia: 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 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 Laperouse Strait, the boundary line is Cape Soya - Cape Crillon. In the Sangar Strait, the border runs along the line of Cape Syria - Cape Estan, and in the Korea Strait - along the line of Cape Nomo (Kyushu Island) - Cape Fukae (Goto Island) - about. Jeju - Korean Peninsula.

The Sea of ​​Japan is one of the largest and deepest seas in the world. Its area is 1062 km 2, volume - 1631 thousand km 3, average depth - 1536 m, 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, Rishiri, Okushiri, Ojima, Sado, Okinoshima, 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, Olga, Peter the Great, Posyet, Korean, on about. Hokkaido - Ishikari, on about. Honshu - Toyama and Wakasa.

Landscapes of the Sea of ​​Japan

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 Korean 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 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.

Bottom relief

Bottom relief and currents of the Sea of ​​Japan

According to the nature of the bottom topography, the Sea of ​​Japan is divided into three parts: the northern one - north of 44 ° N, the central one - between 40 and 44 ° N. and southern - south of 40 ° N.L.

The northern part of the sea is like a wide trough, gradually rising and narrowing towards the north. Its bottom in the direction from north to south forms three steps, which are separated from one another by clearly defined ledges. The northern step is 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 coastal shoal of Primorye in the northern part of the sea is approximately 20 to 50 km long, the edge of the shoal is located 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 by numerous individual uplifts up to 500 m high. Here, on the edge of the southern step, at a latitude of 44 °, there is a vast Vityaz upland with a minimum depth above it of 1086 m.

The southern step of the northern part of the Sea of ​​Japan breaks off as a steep ledge to the bottom of the central basin. The steepness of the ledge is on average 10-12°, in some places 25-30°, and the height is approximately 800-900 m.

The central part of the sea is a deep closed basin, slightly elongated in an east-northeast direction. From the west, north, and east, it is bounded by the steep slopes of the mountain structures of Primorye, the Korean Peninsula, the islands of Hokkaido and Honshu, descending into the sea, and from the south, by the slopes of the underwater height of Yamato.

In the central part of the sea, coastal shallows are very poorly developed. A relatively wide shoal is located 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, is leveled in contrast to the complexly dissected surrounding slopes. 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 with a height of up to 2300 m. The southern part of the sea has a very complex relief, since in this area there are marginal parts of large mountain systems - the Kuril-Kamchatka, Japanese and Ryu-Kyu. Here is located 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 of approximately meridional strike.

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 the Korean Peninsula, wide underwater valleys can be traced between the ridges. The continental shelf almost throughout its length has a width of no more than 40 km. In the area of ​​the Korea Strait, the shoals of the Korean Peninsula and about. Honshu merge and form shallow water with depths of no more than 150 m.

Climate

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 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 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 affected by the effects of 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 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 gale-force winds associated with the passage of cyclones and typhoons, in different areas of the sea, local winds. They are mainly due to the peculiarities of the orography of the coasts and are most noticeable in the coastal zone.

In the Far Eastern seas

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 continental runoff into the Sea of ​​Japan is approximately 210 km 3 /year and is fairly evenly distributed throughout the year. Only in July the river runoff slightly increases.

The 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 the 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.

Hydrology

Essential natural factors- exchange of waters through the straits, the flow of atmospheric 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 out 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.

Scheme of water exchange through the straits in the Sea of ​​Japan

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.

The entire thickness of its waters is divided into two zones: surface - to a depth of an average of 200 m and deep - 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: 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, 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 you move north, its thickness and distribution area gradually decrease, and approximately at about 48 ° N. latitude. due to a sharp decrease in depth, it wedges out in shallow water. In winter, when the Tsushima current weakens, the northern boundary of the Pacific waters is located approximately at 46-47 ° N.L.

Water temperature and salinity

The surface Pacific water is characterized by high temperatures (about 15-20°) and salinity (34-34.5‰). In this water mass, several layers are distinguished, the hydrological characteristics of which and the thickness change throughout 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 has a thickness varying from 50 to 150 m. Significant temperature, salinity and density gradients are noted in it;

the lower layer has a thickness of 100 to 150 m. During the year, its depth and distribution boundaries change; 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 cooling and desalination of Pacific water at latitudes 46-48 ° N.L. the surface water mass of the Sea of ​​Japan is formed. It is characterized by relatively low temperature (about 5-8°C 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‰.

Water temperature on the surface of the seas of Japan, Yellow, East China, South China, Philippine, Sulu, Sulawesi in summer

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 temperatures generally rise 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, a 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 on the horizons of 1000-1500 m) 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.

Salinity on the surface of the Seas of Japan, Yellow, East China, South China, Philippine, Sulu, Sulawesi in summer

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.l‰. 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 about. 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 in most of the sea do not exceed 0.6-0.7‰, and in its central part do not reach

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 the range of 33.9-34.1‰. In summer, the salinity of deep waters is 0.1‰ less than in winter.

Water circulation and currents

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 parts.

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.

On the roads of Tokyo port

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 persistent 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. Deep water rises in this zone. Having rounded the hill, 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 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 Japan 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 runs somewhat south of the 40 ° north latitude, and near the Japanese islands it runs approximately parallel to them almost to the northern tip of the island. 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 of 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 prevail in autumn and winter, and 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.

ice coverage

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, the melting of ice "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.

Economic importance

Inhabitants of the Sea of ​​Japan

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. In summer, tuna, hammerhead fish, and saury penetrate the northern part of the sea. Leading place pollock, sardine and anchovy occupy the species composition of fish catches.

The main ports of the Sea of ​​Japan are Vladivostok, Nakhodka, Vostochny, Sovetskaya Gavan, Vanino, Aleksandrovsk-Sakhalinsky, Kholmsk, Niigata, Tsuruga, Maizuru, Wonsan, Hungnam, Chongjin and Busan, through which not only various cargoes are delivered, but also fish are caught, crabs, trepangs, algae, sea urchins, scallops and much more.

The Sea of ​​Japan has a temperate and monsoonal climate, with its northern and parts much cooler than the southern and eastern parts. The Sea of ​​​​Japan is also rich in typhoons caused by hurricane winds, which often fall on the coast of countries washed by the sea.

The degree of salinity of the Sea of ​​Japan is somewhat lower than that of other waters of the World Ocean - about 33.7-34.3%.

Which islands are located in the Sea of ​​Japan

In total, over 3 thousand islands of various sizes are located in the Sea of ​​Japan, most of which belong to the Japanese archipelago.

The main islands of the sea are Hokkaido (an area of ​​83.4 thousand square kilometers, on which 5.5 million people lived in 2010), Honshu (227.969 thousand square kilometers), Shikoku (18.8 thousand square kilometers and 4.141 million people as of 2005) and Kyushu (40.6 thousand square kilometers and 12 million people living on the island by the end of 2010).

The islands of the so-called Inland Sea of ​​Japan, which connects to the Pacific Ocean through the four straits of Hayasui, Bungo, Kii and Naruto, include the following - Kasado, Hime, Heigun, Yashiro, Itsukushima (an area of ​​​​30.39 square kilometers and 2 thousand inhabitants), Nishinomi , Etajima, Kurahashi, Innoshima, Teshima, Sedo and Awaji (592.17 thousand square kilometers and 157 thousand people as of 2005).

It is quite difficult to list the remaining 3 thousand relatively small islands of the Sea of ​​Japan, but geographers divide them into several groups:
- small islands along the island of Hokkaido;
- along the island of Honshu;
- the islands of the Korea Strait (connects the Japan and East China Seas with a length of 324 kilometers);
- islands of the East China Sea;
- along the island of Shikoku;
- along Kyushu;
- the Ryukyu archipelago (another name is the Likey Islands, a total of 96 large and small ones) also includes several island subgroups - Osumi, Tokara, Amami, Okinawa, Sakishima, Yaeyama, Miyako, Senkaku, Daito and the Borodin Islands.

There are also several artificial islands in the Sea of ​​Japan. One of them - Dejima - was created in the form of a century and served as a port for Dutch ships from the 17th to the middle of the 19th century.

And the Japanese islands are the frontiers delimiting the waters of the Sea of ​​Japan from the Pacific basin. The Sea of ​​Japan is predominantly natural boundaries, only some areas are separated by imaginary lines. The Sea of ​​Japan, although it is the smallest of the Far Eastern seas, belongs to the largest. The area of ​​the water surface is 1062 thousand km2, while the volume of water is about 1630 thousand km3. The depth of the Sea of ​​Japan is on average 1535 m, the maximum depth is 3699 m. This sea belongs to the marginal oceanic seas.

A small number of rivers carry their waters to the Sea of ​​Japan. The largest rivers are: Rudnaya, Samarga, Partizanskaya and Tumnin. Mostly all of this. During the year it is about 210 km 3. During the year, fresh water evenly flows into the sea. In July, the full flow of the rivers reaches its maximum. Between the Pacific Ocean and the water exchange is carried out only in the upper layers.