Seas of Russia - Sea of Japan. Sea of Japan ~ Seas and Oceans Warm current in the Sea of Japan

The Sea of Japan lies between the continent of Asia, the Korean Peninsula, and 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 between Cape Sushchev and Cape Tyk on Sakhalin. In the La Perouse Strait, the border is the line between Cape Soya and 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) - Island. 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, greatest depth - 3699 m. This is a marginal oceanic sea.

There are no large islands in the Sea of Japan. Of the small ones, the most significant are the islands of Moneron, Rishiri, Okushiri, Ojima, Sado, Okinoshima, Ullyndo, Askold, Russky, and Putyatina. Tsushima Island is located in the Korea Strait. 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 relatively slightly indented. The simplest in outline is the coast of Sakhalin; the coasts of Primorye and the Japanese Islands are more winding. The large bays of the mainland coast include De-Kastri, Sovetskaya Gavan, Vladimir, Olga, Peter the Great, Posyet, Koreysky, on the island. Hokkaido - Ishikari, on the island. Honshu - Toyama and Wakasa.

Landscapes of the Sea of Japan

The coastal boundaries are cut through by straits that connect the Sea of Japan with the Pacific Ocean, the Sea of Okhotsk and the East China Sea. The straits vary in length, width and, most importantly, depth, which determines the nature of water exchange 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 located, about 400 m. The Nevelskoy and La Perouse straits connect the Sea of Japan and the Sea of Okhotsk. The Korea Strait, divided by the islands of Jeju, Tsushima and Ikizuki into the western (Broughton passage with the greatest depth of about 12.5 m) and eastern (Kruzenshtern passage with the greatest depth of about 110 m) parts, connects the Sea of Japan and the East China Sea. The 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 and 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.

The coast of the Sea of Japan, varied in structure and external forms in different areas, belongs to different morphometric types of coasts. These are predominantly abrasive, mostly unaltered, shores. To a lesser extent, the Sea of Japan is characterized by accumulative shores. This sea is surrounded by predominantly mountainous shores. In some places, single rocks - kekurs - characteristic formations of the Sea of Japan coast rise from the water. Low-lying shores are found only on certain sections of the coast.

Bottom relief

Bottom topography and currents of the Sea of Japan

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

The northern part of the sea is like a wide trench, 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 located at a depth of 900-1400 m, the middle one 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 sandbank of Primorye in the northern part of the sea is approximately 20 to 50 km long, the edge of the sandbank is located at a depth of about 200 m.

The surfaces of the northern and middle steps of the central trench 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 hill called “Vityaz” with a minimum depth above it of 1086 m.

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

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

In the central part of the sea, coastal shallows are very poorly developed. A relatively wide sandbank is found only in the area of southern Primorye. The edge of the shallows in the central part of the sea is very clearly expressed throughout its entire length. The bottom of the basin, located at a depth of about 3500 m, in contrast to the complexly dissected surrounding slopes, is leveled. On the surface of this plain there are isolated hills. Approximately in the center of the basin there is an underwater ridge stretching from north to south with a height of up to 2300 m. The southern part of the sea has a very complex topography, since in this area there are the marginal parts of large mountain systems - the Kuril-Kamchatka, Japanese and Ryu-Kyu. Here is the vast underwater Yamato Rise, which consists of two ridges elongated in the east-northeast direction with a closed basin located between them. From the south, a wide underwater ridge of approximately meridional strike adjoins the Yamato Rise.

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 is no more than 40 km wide throughout almost its entire length. In the area of the Korea Strait, the shallows of the Korean Peninsula and about. The Honshu close together and form shallow waters 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 gradients of atmospheric pressure. In this regard, strong northwest winds with speeds of 12-15 m/s and more dominate over the sea. Local conditions change wind conditions. In some areas, under the influence of coastal topography, there is a high frequency of northern winds, while in others, calms are often observed. On the southeast coast, the regularity of the monsoon is disrupted; western and northwestern winds predominate here.

During the cold season, continental cyclones enter the Sea of Japan. They cause strong storms, and sometimes severe hurricanes, which last for 2-3 days. At the beginning of autumn (September), tropical cyclones-typhoons sweep over the sea, accompanied by hurricane 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 Hawaiian High and, to a lesser extent, by the depression that forms in the summer over Eastern Siberia. In this regard, southern and southwestern winds prevail over the sea. However, pressure gradients between areas of high and low pressure are relatively small, so wind speeds average 2-7 m/s. A significant increase in wind is associated with the entry of oceanic, and less often continental, cyclones into the sea. In summer and early autumn (July-October), the number of typhoons over the sea increases (with a maximum in September), causing 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 areas of the sea. They are mainly caused by the peculiarities of coastal orography and are most noticeable in the coastal zone.

In the Far Eastern seas

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

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. Continental flow into the Sea of Japan is approximately 210 km 3 /year and is fairly evenly distributed throughout the year. Only in July does the river flow increase slightly.

The geographical location, 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 large amount of heat from the sun. However, the total heat consumption for effective radiation and evaporation exceeds the supply of solar heat, therefore, as a result of processes occurring at the water-air interface, the sea loses heat annually. It is replenished by the heat brought by Pacific waters entering the sea through the straits, therefore, on the average long-term value, the sea is in a state of thermal equilibrium. This indicates the important role of water heat exchange, mainly heat influx from outside.

Hydrology

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

Scheme of water exchange through 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 areas of the Pacific Ocean, but has its own characteristics that 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. The characteristics of surface water under the influence of climatic and hydrological factors change in time and space much more intensely.

In the Sea of Japan, three water masses are distinguished: two in the surface zone: the surface Pacific, characteristic of the southeastern part of the sea, and the surface Sea of Japan - 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 area of distribution gradually decrease, and at approximately 48° N latitude. due to a sharp decrease in depth, it wedges out into shallow water. In winter, when the Tsushima Current weakens, the northern boundary of the Pacific waters is located at approximately 46-47° N latitude.

Water temperature and salinity

Surface Pacific water is characterized by high temperatures (about 15-20°) and salinity (34-34.5‰). This water mass contains several layers, the hydrological characteristics of which and their thickness vary throughout the year:

the surface layer, where the temperature throughout the year varies from 10 to 25°, and salinity - from 33.5 to 34.5‰. The thickness of the surface layer varies from 10 to 100 m;

the upper intermediate layer has a thickness varying from 50 to 150 m. It exhibits significant gradients in temperature, salinity and density;

the lower layer has a thickness of 100 to 150 m. The depth of its occurrence and the boundaries of its distribution change throughout the year; temperature varies from 4 to 12°, salinity - from 34 to 34.2‰. The lower intermediate layer has very slight vertical gradients in temperature, salinity and density. It separates the surface Pacific water mass from the deep Sea of Japan.

As you move north, the characteristics of Pacific water gradually change under the influence of climatic factors as a result of its mixing with the underlying deep Sea of Japan water. With the cooling and desalination of 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 (on average about 5-8°) 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 Ocean, in the surface water of the Japanese Sea, the greatest changes in hydrological characteristics occur in the surface layer with a thickness of 10 to 150 m or more. The temperature here varies throughout the year 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 descend to depths due to the process of winter convection. The vertical changes in the characteristics of the deep Sea of Japan water are extremely small. The bulk of these waters have a temperature of 0.1-0.2° in winter, 0.3-0.5° in summer, and a salinity throughout the year of 34.1-34.15‰.

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

The structural features of the waters of the Sea of Japan are well illustrated by the distribution of oceanological characteristics in it. Surface water temperatures generally increase from northwest to southeast.

In winter, the water temperature on the surface 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-defined contrast in water temperature between the western and eastern parts of the sea, and in the south it is weaker than in the north and central part of the sea. Thus, at the latitude of Peter the Great Bay, the water temperature in the west is close to 0°, and in the east it reaches 5-6°. This is explained, in particular, by the 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 quickly. At this time, 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.

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

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 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 1-1. 5° at horizons of 400-500 m, deeper the temperature drops slightly (to values less than 1°) and remains approximately the same to the bottom.

In summer, in the north and northwest of the sea, high surface temperature (18-20°) is observed in the 0-15 m layer, from here it drops sharply with a depth of up to 4° at a horizon of 50 m, then its decrease occurs 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 quite smoothly with depth and at a horizon of 200 m is approximately 6°, from here it decreases somewhat faster and at horizons of 250-260 m it is equal to 1.5-2°, then it decreases very slowly at horizons 750-1500 m (in some areas at horizons of 1000-1500 m) reaches a minimum of 0.04-0.14°, from here the temperature rises towards the bottom to 0.3°. The formation of an intermediate layer of minimum temperature values is presumably associated with the immersion of the waters of the northern part of the sea, cooled during 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, Philippines, Sulu, Sulawesi in summer

The average salinity of the Sea of Japan, approximately 34.1‰, is slightly 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 surface salinity (about 33.8‰) is observed along the southeastern and southwestern coasts, where heavy precipitation causes some desalination. In most of the sea, salinity is 34.l‰. In spring, in the north and northwest, desalination of surface water occurs due to melting ice, and in other areas it is associated with an increase in precipitation. Salinity remains relatively high (34.6-34.7‰) in the south, where at this time the influx of saltier waters entering 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 variation of salinity is generally characterized by small changes in its values along the depth.

In winter, most of the sea experiences a uniform salinity from surface to bottom, equal to approximately 34.1‰. Only in coastal waters is there a weakly expressed minimum salinity in the surface horizons, below which the salinity increases slightly and remains almost the same to the bottom. At this time of year, vertical changes in salinity in most of the sea do not exceed 0.6-0.7‰, and in its central part they do not reach

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

In summer, minimal salinity is observed on the surface as a result of noticeable desalination of surface waters. In subsurface layers, salinity increases with depth, creating noticeable vertical salinity gradients. The maximum salinity at this time is observed at horizons of 50-100 m in the northern regions and at horizons of 500-1500 m in the southern regions. Below these layers, salinity decreases slightly and remains almost unchanged 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 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 surface density is quite uniform throughout the sea, especially in its northwestern part.

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

In summer, horizontal differences in surface density values are greatest. They are especially significant in the area of mixing waters with different characteristics. In winter, the density is approximately the same from surface to bottom in the northwestern part of the sea. In the southeastern regions, the density increases slightly at 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 interlayered in density. It is small on the surface, rises sharply at horizons of 50-100 m and increases more gradually deeper to the bottom. In the southwestern part of the sea, the density increases noticeably in the subsurface (up to 50 m) layers, at horizons of 100-150 m it is quite uniform, below the density increases slightly to the bottom. This transition occurs at horizons of 150-200 m in the northwest and at horizons of 300-400 m in the southeast of the sea.

In autumn, the density begins to level out, which means a transition to a winter type of density distribution with depth. Spring-summer density stratification determines a fairly stable state of the waters of the Sea of Japan, although it is expressed to varying degrees in different areas. In accordance with this, more or less favorable preconditions are created in the sea for the emergence and development of mixing.

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 about 20 m. In the less stratified waters of the southern and southwestern regions, the wind mixes the upper layers to the horizons 25-30 m. In autumn, stratification decreases and winds increase, but at this time of year the thickness of the upper homogeneous layer increases due to density mixing.

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

On the roadstead of Tokyo port

The nature of the circulation of sea waters is determined not only by the influence of the winds acting directly above the sea, but also by the circulation of the atmosphere over the northern part of the Pacific Ocean, since the strengthening or weakening of the influx of Pacific waters depends on it. In summer, the southeast monsoon increases water circulation due to the influx of large amounts of water. In winter, the persistent northwest monsoon prevents the flow of water into the sea through the Korea Strait, causing weakening water circulation.

Through the Korea Strait, the waters of the western branch of the Kuroshio, which passed through the Yellow Sea, enter the Sea of Japan and spread in a wide stream to the northeast along the Japanese islands. This flow is called the Tsushima Current. In the central part of the sea, the Yamato Rise divides the flow of Pacific waters into two branches, forming a divergence zone, which is especially pronounced in the summer. In this zone, deep waters rise. After going around the hill, both branches connect in an area located in 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, towards the Korea Strait, and turns into a countercurrent along the coast of the Korean Peninsula. The bulk of the Pacific waters are carried out from the Sea of Japan through the Sangarsky and La Perouse straits, while some of the waters, having reached the Tatar Strait, give rise to the cold Primorsky Current, moving south. South of Peter the Great Bay, the Primorsky Current turns east and merges with the northern branch of the Tsushima Current. A small part of the water continues to move south to Korea Bay, where it flows into the countercurrent formed by the waters of the Tsushima Current.

Thus, moving along the Japanese Islands from south to north, and along the coast of Primorye - from north to south, the waters of the Sea of Japan form a cyclonic gyre centered in the northwestern part of the sea. In the center of the gyre, rising waters are also possible.

In the Sea of Japan, two frontal zones are distinguished - the main polar front, formed by the warm and salty 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 in summer have a higher temperature and lower salinity than the waters of the Primorsky Current. In winter, the polar front passes slightly south of the parallel of 40° N, 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 moves slightly 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 Sangar Straits.

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

The nature of the tide corresponds to tidal currents. In open areas of the sea, semidiurnal tidal currents with speeds of 10-25 cm/s are mainly observed. Tidal currents in the straits are more complex, where they have very significant speeds. Thus, in the Sangar Strait, tidal current speeds 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 it does not exceed 1.5 m.

In the middle part of the sea the tides are low. Along the eastern coasts of the Korean Peninsula and Soviet Primorye, up to the entrance to the Tatar Strait, they are no more than 0.5 m. The tides are of the same magnitude off the western coasts of Honshu, Hokkaido and Southwestern Sakhalin. In the Tatar Strait, the tide height is 2.3-2.8 m. In the northern part of the Tatar Strait, the tide heights increase, which is determined by its funnel-shaped shape.

In addition to tidal fluctuations, seasonal level fluctuations are well expressed in the Sea of Japan. In summer (August - September) the maximum rise in level is observed on all shores of the sea; in winter and early spring (January - April) the minimum level is observed.

In the Sea of Japan, surge level fluctuations are observed. During the winter monsoon off the western coast of Japan, the level can rise by 20-25 cm, and off the mainland coast it can drop by the same amount. In summer, on the contrary, off the coast of North Korea and Primorye the level rises by 20-25 cm, and off the Japanese coast it drops by the same amount.

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

The northern and northwestern parts of the sea, adjacent to the mainland coast, are covered with ice annually for 4-5 months, the area of which occupies about 1/4 of the entire sea.

Ice cover

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.

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

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

Every year, only the northern bays of the mainland coast freeze completely. South of Sovetskaya Gavan, the fast ice in the bays is unstable and can break up repeatedly during the winter. In the western part of the sea, floating and stationary ice appears earlier than in the eastern part; 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 spreading from the mainland. In the east of the sea, the influence of these masses weakens significantly, and at the same time the role of warm and humid marine air masses increases. The ice cover reaches its greatest development around mid-February. From February to May, conditions favorable for ice melting (in situ) are created throughout the sea. In the eastern part of the sea, ice melting “begins earlier and occurs more intensely than at the same latitudes in the west.

Ice cover in the Sea of Japan varies significantly from year to year. There may be cases when the ice cover in one winter is 2 times or more greater than the ice cover in 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 include sardine, anchovy, mackerel, and horse mackerel. In the northern regions, the main fish caught are mussels, flounder, herring, greenling and salmon. In summer, tuna, hammerfish, and saury penetrate into the northern part of the sea. The leading place in the species composition of fish catches is occupied by pollock, sardine and anchovy.

Japanese Sea- a marginal sea of the Pacific Ocean, located between the mainland of Eurasia, the Korean Peninsula and the islands of Sakhalin, Hokkaido and Honshu. The countries washed by this sea are Russia, Japan, North Korea and South Korea. The Sea of Japan is one of the largest and deepest seas in the world. Its area is 1062 km 2, volume - 1631 thousand km 3, average depth - 1536 m, greatest depth - 3699 m. This is a marginal oceanic sea. There are no large islands in the Sea of Japan. Of the small ones, the most significant are the islands of Moneron, Rishiri, Okushiri, Ojima, Sado, Okinoshima, Ullyndo, Askold, Russky, and Putyatina. Tsushima Island is located in the Korea Strait. Almost all the islands are located near the coast. Most of them are located in the eastern part of the sea. The coastline of the Sea of Japan is relatively slightly indented. The simplest in outline is the coast of Sakhalin; the coasts of Primorye and the Japanese Islands are more winding.

Sailing

The study of the Sea of Japan in Russia began (by the detachments of the Great Northern, or Second Kamchatka, expedition of 1733-43) by determining the geographical location of the islands of Japan and Sakhalin and partially photographing their coasts. In 1806, surveys of the eastern coast of the Sea of Japan were carried out by the expedition of I. F. Krusenstern and Yu. F. Lisyansky during their circumnavigation of the world (1803-1806). The discovery in 1849 by G.I. Nevelsky of the strait between the mainland and the island was important. Sakhalin. Since 1880, a permanent Hydrographic Expedition began its work, ensuring the compilation of accurate navigation maps. Simultaneously with hydrographic work, observations of water temperature and surface currents were carried out. Extensive oceanographic work in the Pacific Ocean and Far Eastern seas began in 1888, with the voyage of S. O. Makarov on the corvette Vityaz. Makarov made careful deep-sea observations in the La Perouse Strait for the first time; Oceanographers still use this data to this day.

During World War II, the study of the sea was sporadic. After the war, especially with the arrival of the special expedition vessel of the Institute of Oceanology of the USSR Academy of Sciences “Vityaz”, research work in the Far Eastern seas reached enormous proportions.

Bottom relief

Based on the nature of the bottom topography, the Sea of Japan is divided into three parts: northern, central and southern. The northern part of the sea is a wide trench, gradually rising and narrowing towards the north. The central part of the sea is a deep closed basin, slightly elongated in the east-northeast direction. The southern part of the sea has a very complex topography with alternating troughs and relatively shallow areas. Here is the vast underwater rise of Yamato.

Climate and hydrological regime

The climate of the Sea of Japan is temperate, monsoonal. The northern and western parts of the sea are much colder than the southern and eastern. In the coldest months (January-February), the average air temperature in the northern part of the sea is about -20 o C, and in the south about +5 o C. The summer monsoon brings with it warm and humid air. The average air temperature of the warmest month (August) in the northern part is approximately +15 o C, in the southern regions about +25 o C. In autumn, the number of typhoons caused by hurricane winds increases. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m.

In winter, the temperature of surface waters from -1 to 0 o C in the north and northwest rises to +10-14 o C in the south and southeast. Spring warming entails a fairly rapid increase in water temperature throughout the sea. In summer, the surface water temperature rises from +18-20 o C in the north to +25-27 o C in the south of the sea. The salinity of the water in the Sea of Japan is 33.7-34.3‰, which is slightly lower than the salinity of the waters of the World Ocean. The tides in the Sea of Japan are distinct, to a greater or lesser extent in different areas. The greatest level fluctuations are observed in the extreme northern and extreme southern regions and reach 3 meters. The appearance of ice in the Sea of Japan is possible as early as October, and the last ice lingers in the north sometimes until mid-June. Every year, only the northern bays of the mainland coast freeze completely. In the western part of the sea, floating, stationary ice appears earlier than in the eastern part, and it is more stable.

Flora and fauna

The Sea of Japan is one of the most productive. Along the coast, algae form powerful thickets; The benthos is diverse and large in biomass. The abundance of food and oxygen, the influx of warm waters create favorable conditions for the development of fish fauna. The fish population of the Sea of Japan includes 615 species. Here you can find octopuses and squids - typical representatives of warm seas. At the same time, vertical walls overgrown with sea anemones, gardens of brown algae - kelp - all this is reminiscent of the landscapes of the White and Barents Seas. In the Sea of Japan there is a huge abundance of starfish and sea urchins, of various colors and sizes, brittle stars, shrimps, and small crabs are found (Kamchatka crabs are found here only in May, and then they move further into the sea). Bright red ascidians live on rocks and stones. The most common shellfish is scallops. Among the fish, blennies and sea ruffes are often found. In the Sea of Japan you can find fur seals that come here for the winter from more northern regions, representatives of earless seals - seals, dolphins and even whales.

Economic importance

The Sea of Japan is characterized by high development of two industries. Fisheries combine fishing (sardine, mackerel, saury and other species) and the extraction of non-fish objects (sea shellfish - mussels, scallops, squid; algae - kelp, seaweed, ahnfeltia). The leading place in the species composition of fish catches is occupied by pollock, sardine and anchovy. Fishing in most parts of the sea continues all year round. In the Sea of Japan, active work is underway to breed mariculture - the most promising method of using marine biological resources. On the shores of the Sea of Japan, in Vladivostok, the Trans-Siberian Railway ends. The most significant transshipment transport hub is located here, where cargo is exchanged between rail and sea transport. Further along the Sea of Japan, cargo travels on sea vessels to various foreign and Russian ports, just as they arrive from other ports to the ports of the Sea of Japan: Nakhodka, Vanino, Aleksandrovsk-on-Sakhalin, Kholmsk. These ports provide maritime transport not only in the Sea of Japan, but also beyond it. Since the 1990s, the coast of the Sea of Japan off the coast of Primorye has begun to be actively developed by local and visiting tourists. The impetus was factors such as the abolition or simplification of visiting the border zone, the rise in the cost of passenger transportation around the country, which made it too expensive for Far Easterners to vacation on the Black Sea coast, as well as the greatly increased number of personal vehicles, which made the Primorye coast accessible to residents of Khabarovsk and the Amur region.

The resource base of minerals in the Russian part of the Sea of Japan is insignificant. The Izylmetyevskoe gas field was discovered on the West Sakhalin shelf of the sea, but it is unprofitable for exploitation. Promising areas with sand were identified on the continental shores of the sea.

Ecology

The Sea of Japan abounds in flora and fauna suitable for industrial production. Fishing fleets of states are actively fishing and catching crabs, sea cucumbers, algae, sea urchins and scallops. At the same time, there are problems associated with it. The discrepancy between the amount of fish and shellfish caught and the volume of their natural restoration leads to the death and extinction of some of their species. The share of poaching in this is large. In addition, the fleet pollutes sea waters with waste fuels and lubricants, oil products, waste and sewage. This applies not only to fishing vessels, but also to the merchant and military fleets of the four powers. Nuclear fleet bases in the ports of the Sea of Japan, disposal and disposal of used radioactive substances and ships removed from combat duty require close attention and control.

The main source of pollution is the city of Vladivostok. The wastewater from its industrial enterprises, city sewerage, and products from the economic activities of the port and ship repair yards end up in the waters of the Amur and Ussuri Bays, and most of all, in the aquatic environment of the Golden Horn Bay.

The southernmost of the Russian Far East lies between the Asian mainland and the Korean peninsula, and the Japanese, separating it from other Pacific seas and the ocean itself.
The Sea of Japan is dominated by natural boundaries, but in some areas it is limited by conventional lines.
In the north, the border between the Sea of Japan and the Sea of Okhotsk runs along the line between Cape Sushchev and Cape Tyk.
In the La Perouse Strait, the border is the line between Cape Crillon and Cape Soya. In the Sangar Strait, the border runs along the line of Cape Syria - Cape Esan, and in the Korea Strait along the line of Cape Nomo (Kyushu Island) - Cape Fukae (Goto Island) - Island. Jeju - Korean Peninsula.

Within these boundaries, the sea is contained between parallels 51°45′ and 34°26′ N. w. and meridians 127°20′ and 142°15′ E. d.

The configuration is characterized by a large length along the meridian, expansion in the central and southern parts and narrowing in the north.

Second in size to the Bering and Okhotsk Seas, the Sea of Japan is one of the largest and deepest seas in our country. Its area is 1062 thousand km2, volume 1630 thousand km3, average depth 1535 m, greatest depth 3699 m.
The geographical location and predominantly large depths indicate that the Sea of Japan belongs to the marginal oceanic seas.

There are no large islands. Of the small ones, the most significant islands are: Moneron, Rebun, Rishiri, Okushiri, Oshima, Sado, Okioshima, Ullyndo, Askold, Russky, Putyatin. The Tsushima Islands are located in the Korea Strait. All islands, except Ulleungdo, are located near the coast. Most of the islands are located in the eastern part of the sea.

Ezhovaya Bay Sea of Japan

GENERAL INFORMATION -
The Sea of Japan (Japanese 日本海 nihonkai, cor. 동해 donghae, “eastern sea”) is a sea within the Pacific Ocean, separated from it by the Japanese islands and. By origin, it is a deep-sea pseudo-abyssal intra-shelf depression connected with other seas and the Pacific Ocean through 4 straits: Korean (Tsushima), Sangarsky (Tsugaru), La Perouse (Soya), Nevelsky (Mamiya). It washes the shores of Russia, Japan, the Republic of Korea and the DPRK.
A branch of the warm Kuroshio Current enters in the south.

Cape Bruce Sea of Japan

CLIMATE
The climate is temperate, monsoon. The northern and western parts of the sea are much colder than the southern and eastern. In the coldest months (January-February), the average air temperature in the northern part of the sea is about −20 °C, and in the south about +5 °C. The summer monsoon brings warm and humid air. The average air temperature of the warmest month (August) in the northern part is approximately +15 °C, in the southern regions about +25 °C. In autumn, the number of typhoons caused by hurricane winds increases. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m.

Currents
Surface currents form a gyre, which consists of the warm Tsushima Current in the east and the cold Primorsky Current in the west. In winter, the temperature of surface waters rises from −1–0 °C in the north and northwest to +10–+14 °C in the south and southeast. Spring warming entails a fairly rapid increase in water temperature throughout the sea. In summer, the surface water temperature rises from 18–20 °C in the north to 25–27 °C in the south of the sea.
The vertical distribution of temperature is not the same in different seasons in different areas of the sea. In summer, in the northern regions of the sea, the temperature is 18–10 °C in a layer of 10–15 m, then it sharply drops to +4 °C at a horizon of 50 m and, starting from a depth of 250 m, the temperature remains constant around +1 °C. In the central and southern parts of the sea, the water temperature decreases quite smoothly with depth and at a horizon of 200 m reaches +6 °C; starting from a depth of 250 m, the temperature remains around 0 °C.

The salinity of the water in the Sea of Japan is 33.7–34.3‰, which is slightly lower than the salinity of the waters of the World Ocean.

Tides in the Sea of Japan are clearly expressed, to a greater or lesser extent in different areas. The greatest level fluctuations are observed in the extreme northern and extreme southern regions. Seasonal fluctuations in sea level occur simultaneously over the entire surface of the sea; the maximum rise in level is observed in summer.

Rudnevo Bay Sea of Japan

Ice conditions
According to ice conditions, it can be divided into three areas: the Tatar Strait, the area along the coast of Primorye from Cape Povorotny to Cape Belkin and Peter the Great Bay. In winter, ice is constantly observed only in the Tatar Strait and Peter the Great Bay; in the rest of the water area, with the exception of closed bays and bays in the northwestern part of the sea, it does not always form.
The coldest area is the Strait of Tartary, where more than 90% of all ice observed in the sea is formed and localized during the winter season. According to long-term data, the duration of the period with ice in the Peter the Great Gulf is 120 days, and in the Tatar Strait - from 40-80 days in the southern part of the strait, to 140-170 days in its northern part.

The first appearance of ice occurs at the tops of bays and bays, closed from wind and waves and having a desalinated surface layer. In moderate winters in Peter the Great Bay, the first ice forms in the second ten days of November, and in the Tatar Strait, at the tops of Sovetskaya Gavan, Chikhachev Bays and Nevelskoy Strait, primary forms of ice are observed already in early November. Early ice formation in the Peter the Great Gulf (Amur Bay) occurs in early November, in the Tatar Strait - in the second half of October. Later - at the end of November.
In early December, the ice cover develops along the ice faster than near the mainland coast. Accordingly, at this time there is more ice in the eastern part of the Tatar Strait than in the western part. By the end of December, the amount of ice in the eastern and western parts is equalized, and after reaching the parallel of Cape Syurkum, the direction of the edge changes: its displacement along the Sakhalin coast slows down, and along the continental coast it intensifies.
In the Sea of Japan, the ice cover reaches its maximum development in mid-February. On average, ice covers 52% of the area of the Tatar Strait and 56% of the Peter the Great Bay.

Ice melting begins in the first half of March. In mid-March, the open waters of Peter the Great Bay and the entire coastal coast up to Cape Zolotoy are cleared of ice. The ice boundary in the Tatar Strait retreats to the northwest, and in the eastern part of the strait clearing of ice occurs at this time. Early clearing of the sea from ice occurs in the second ten days of April, later - at the end of May - beginning of June.

FLORA AND FAUNA
The underwater world of the northern and southern regions is very different. In the cold northern and northwestern regions, the flora and fauna of temperate latitudes has formed, and in the southern part of the sea, south of Vladivostok, a warm-water faunal complex predominates. Off the coast of the Far East, a mixture of warm-water and temperate fauna occurs.
Here you can find octopuses and squids - typical representatives of warm seas. At the same time, vertical walls overgrown with sea anemones, gardens of brown algae - kelp - all this is reminiscent of the landscapes of the White and Barents Seas. In the Sea of Japan there is a huge abundance of starfish and sea urchins, of various colors and sizes, brittle stars, shrimps, and small crabs are found (Kamchatka crabs are found here only in May, and then they move further into the sea). Bright red ascidians live on rocks and stones. The most common shellfish is scallops. Among the fish, blennies and sea ruffes are often found.

Sea transport
Main, Nakhodka, Vostochny, Sovetskaya Gavan, Vanino, Aleksandrovsk-Sakhalinsky, Kholmsk, Niigata, Tsuruga, Maizuru, Wonsan, Hungnam, Chongjin, Busan.

Fishing; production of crabs, sea cucumbers, algae, sea urchin; scallop cultivation.

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

Gamow lighthouse Sea of Japan

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

STRAITS
The Korea Strait is a strait between the Korean Peninsula and the islands of the Japanese archipelago of Iki, Kyushu and the southwestern tip of Honshu.
Connects the Sea of Japan and the East China Sea. The length of the strait is 324 km, the smallest width is 180 km, the smallest depth in the fairway is 73 m. Tsushima Island divides the Korea Strait into the Eastern (Tsushima Strait) and Western passages. Japanese Sea

The Sangar Strait or Tsugaru Strait (Japanese: 津軽海峡 Tsugaru-kaikyo:?) is a strait between the Japanese islands of Honshu and Hokkaido, connecting the Sea of Japan with the Pacific Ocean. The width of the strait is 18-110 km, length - 96 km. The depth of the navigable part varies from 110 to 491 m.
There are many good anchorages in the strait, but there are no places completely sheltered from the wind. The main current is directed from west to east, the current speed in the middle of the strait is about 3 knots. The flow often branches into several separate jets, periodically changing their direction. Tides up to 2 m.
Both banks are mountainous and covered with forest. On the shore of the island of Hokkaido in the Sangar Strait is the city of Hakodate - at the beginning of the twentieth century, the seat of the Russian consulate and the port most visited by Russian Amur ships. The first map of the Sangar Strait was compiled by the Russian admiral I.F. Krusenstern. From the southern side of the strait, Mutsu Bay, on which the port city of Aomori is located, juts deep into the land to the south.
In winter the strait does not freeze. The Seikan Tunnel runs under the strait - before the Gotthard Base Tunnel was put into operation, the longest railway tunnel in the world.

La Perouse Strait is a strait between the northern tip of the island of Hokkaido (Japan) and the southern tip of Cape Crillon (Russian Federation), connecting the Sea of Japan and the Sea of Okhotsk.
Length 94 km, width at the narrowest part 43 km, average depth 20-40 m, maximum depth 118 m. In winter, the strait is covered with ice. Named in honor of the French navigator Jean Francois de La Perouse, who discovered the strait in 1787.
The port of Wakkanai is located on the Japanese shore of the strait. In the strait there is a rocky island called the Stone of Danger.
Unlike the usually declared 12-mile (22 km) zone of territorial waters, Japan claims territorial rights in Sōya Bay only three nautical miles from Hokkaido Island (5.5 km). According to Japanese media reports, this rule has been in effect since the late 1970s to ensure that when US warships and submarines carrying nuclear weapons pass through the straits, there is no violation of Japan’s declared nuclear-free status. Although previously some ministers publicly denied that the width of the zone was changed in order to maintain the nuclear-free status.

The Nevelskoy Strait is a strait between the continent of Eurasia and. Connects the Tatar Strait with the Amur Estuary. The length is about 56 km, the smallest width is 7.3 km, the depth in the fairway is up to 7.2 m.
Named in honor of G.I. Nevelskoy, who discovered the strait in 1849.
During Stalin's reign, it was planned to build a tunnel under the strait.

Petrov Island, Singing Sands Bay

DETAILED GEOGRAPHY AND
The coastline of the Sea of Japan is relatively weakly indented and does not form bays and bays that protrude deeply into the land, as well as capes that protrude far into the sea. The coasts of Primorye and the Japanese Islands are the simplest in outline. The large bays of the mainland coast include: Sovetskaya Gavan, Vladimir, Olga, Peter the Great, Posyet, East Korean; on o. Hokkaido - Ishikari, on the island. Honshu - Toyama and Wakasa. The most noticeable capes are Lazareva, Peschany, Povorotny, Gromova, Pogibi, Tyk, Korsakova, Krillon, Soya, Nosyappu, Tappi, Nyuda and some others.

The coastline is cut through by straits that connect the Sea of Japan with the Pacific Ocean, the Sea of Okhotsk and the East China Sea. The straits vary in length, width and, most importantly, depth, which determines the nature of water exchange between the Sea of Japan and neighboring basins. Through the Sangar Strait, the Sea of Japan communicates directly with the Pacific Ocean. The depth of the strait in the western part is about 130 m, in the eastern part, where its maximum depths are located, it is about 400 m. The Nevelskoy Strait connects the Sea of Japan and the Sea of Okhotsk. The Korea Strait, divided by the islands of Gojedo, Tsushima and Iki into the western (Broughton Passage with the greatest depth of about 12.6 m) and the eastern (Kruzenshtern Passage with the greatest depth of about 110 m), connects the Sea of Japan and the East China Sea. The Shimonoseki Strait, with depths of about 2-3 m, connects the Sea of Japan and the Inland Sea of Japan. Such shallow depths of the straits with large depths of the sea itself create conditions for its morphometric isolation from the Pacific Ocean and adjacent seas, which is the most important natural feature of the Sea of Japan.

Cape Balyuzek, Vladimir Bay, moonlit night

The coast of the Sea of Japan, varied in structure and external forms in different areas, belongs to different morphometric types of coasts. From Fig. 42 it is clear that abrasion coasts predominate here, mostly little changed by the sea, although the coasts also have a noticeable extent; modified by sea activity. To a lesser extent, the Sea of Japan is characterized by accumulative shores. This sea is surrounded by predominantly mountainous shores. In some places, single rocks (kekurs), characteristic formations of the coast, rise from the water. Low-lying shores are found only on certain sections of the coast.

The depth distribution in the Sea of Japan is complex and varied. According to the nature of the bottom topography, it is divided into three parts: northern - north of 44° N. latitude, central - between 40 and 44° N. w. and southern - south of 40° N. w.

The northern part of the sea is like a wide trench, gradually narrowing towards the north. Its bottom in the direction from north to south forms three steps, which are separated from one another by clearly defined ledges. The northern step is located at a depth of 900–1400 m, the middle one at depths of 1700–2000 m, and the southern one at a depth of 2300–2600 m; the surfaces of the steps are slightly inclined to the south. The transition from step to step sharply complicates the bottom topography.

The coastal shoal of Primorye in the northern part of the sea has a width of 10 to 25 miles, the edge of the shoal is located at a depth of about 200 m. The surfaces of the northern and middle stages of the central trench are more or less leveled. The relief of the southern step is significantly complicated by the large number of individual rises located here - up to 500 m above the bottom surface. Here, on the edge of the southern step, at a latitude of 44°, there is a vast Vityaz upland with a minimum depth above it of 1086 m. The southern step of the northern part of the Sea of Japan breaks off with a steep ledge to the bottom of the central basin. The steepness of the ledge is on average 10-12°, in some places 25-30°, and the height is approximately 800-900 m.
The central part of the sea is a deep closed basin, slightly elongated in the east-northeast direction. From the west, north and east, it is limited by steep ledges of the mountain slopes of Primorye, Korea, the islands of Hokkaido and Honshu that go below sea level, and from the south by the slopes of the Yamato underwater rise.

Dubovaya Bay Sea of Japan

The central part of the sea is characterized by very weak development of coastal shallows. A relatively wide shoal is observed only in the area of southern Primorye. The edge of the shallows in the central part of the sea is very clearly expressed throughout its entire length. The bottom of the basin, located at a depth of about 3500 m, in contrast to the complexly dissected surrounding slopes, is completely leveled. On the surface of this plain there are isolated hills. Approximately in the center of the basin there is an underwater ridge stretching from north to south with a height of up to 2300 m. The southern part of the sea has a very complex topography, since in this area there are the ends of large mountain systems: the Kuril-Kamchatka, the Japanese and the Ryukyu. The central place here is occupied by the vast underwater Yamato Rise, which consists of two ridges elongated in the east-northeast direction with a closed basin located between them. From the south, a wide underwater ridge adjoins the Yamato Rise, stretching in a close meridional direction from the Oki Islands.
In many areas of the southern part of the sea, the structure of the underwater slope is complicated by the presence of underwater ridges. On the underwater slope of Korea, wide underwater valleys can be traced between the ridges. The mainland shelf near Korea is narrow throughout almost its entire length, its width does not exceed 10 miles. In the area of the Korea Strait, the shoals of Korea and Honshu meet and form shallow waters with depths of no more than 150 m.

The Sea of Japan lies entirely in the monsoon climate zone of temperate latitudes. In this sea, the named type of climate manifests itself most clearly. However, under the influence of various physical and geographical factors, for example, the large meridional and small latitudinal extent of the sea, the proximity of the cold Sea of Okhotsk in the north and the warm Pacific Ocean in the south, local features of atmospheric circulation, etc., noticeable climatic differences are formed between different areas of the sea. In particular, the northern and western parts of the sea are colder than the southern and eastern parts; each of them has a certain weather pattern.

Synoptic conditions over the sea and associated meteorological indicators determine the main centers of atmospheric action, the location and interaction of which varies from season to season. In the cold season (from October to March), the sea is influenced by the Siberian anticyclone and the Aleutian low, which creates significant horizontal pressure gradients. In this regard, strong northwest winds with speeds of 12-15 m/s and more dominate over the sea. Local conditions change wind conditions. In some areas, under the influence of coastal topography, there is a high frequency of northern winds, while in others, calms are often observed. On the southeast coast, the regularity of the monsoon is disrupted; western and northwestern winds predominate here.

During the cold season, continental cyclones enter the Sea of Japan. They cause strong storms and sometimes severe hurricanes that last for 2-3 days. At the beginning of autumn (September - October), tropical cyclones - typhoons, accompanied by hurricane winds - sweep over the sea. The winter monsoon brings dry and cold air to the Sea of Japan, the temperature of which increases from south to north and from west to east. In the coldest months (January or February), the average monthly air temperature in the north is about −20°, and in the south about 5°, although significant deviations from these values are often observed. During the cold seasons, the weather is dry and clear in the northwestern part of the sea, wet and cloudy in its southeast.

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

The summer monsoon brings warm and humid air. The average monthly temperature of the warmest month (August) in the northern part of the sea is approximately 15°, and in the southern regions about 25°. In the northwestern part of the sea, significant cooling is observed due to the influx of cold air brought by continental cyclones. In spring and summer, cloudy weather with frequent fogs prevails. The monsoon type of climate with all its features (changes in winds, weather patterns, etc.) is an essential natural feature of the Sea of Japan.

Sea of Japan, South Korea

Another distinctive feature of this sea is the relatively small number of rivers flowing into it. The largest of them are Rudnaya, Samarga, Partizanskaya, Tumnin. Almost all of them have a mountain character. Continental flow into the Sea of Japan is approximately 210 km3/year and is fairly evenly distributed across months. Only in July is there a slight increase in river flow.
The unique geographical location, outline and basin of the sea, separated from the Pacific Ocean and adjacent seas by high thresholds in the straits, pronounced monsoons, water exchange through the straits only in the upper layers are the main factors in the formation of the hydrological conditions of the Sea of Japan.

Located in temperate latitudes, the Sea of Japan receives a large amount of heat from solar radiation. However, the total heat consumption for effective radiation and evaporation exceeds the solar heat input. Consequently, as a result of processes occurring at the water-air interface, the sea loses heat annually. It is replenished by the heat brought by Pacific waters entering the sea through the straits, therefore, on the average long-term value, the sea is in a state of thermal equilibrium. This indicates a very important role of intra-water heat exchange, mainly external heat influx, in the heat balance of the Sea of Japan.

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

Hydrological characteristics.
The impact of the noted factors determines the distribution of temperature, salinity and water density in time and space, the structure and circulation of the waters of the Sea of Japan.
Features of the distribution of water temperature in the sea are formed under the influence of heat exchange with the atmosphere (this factor prevails in the northern and northwestern regions) and water circulation, which prevails in the southern and southeastern parts of the sea. In general, the water temperature at the sea surface rises from the northwest to the southeast, with each season having its own distinctive features.
In winter, the surface water temperature rises from negative values close to 0° in the north and northwest to 10-14° in the south and southeast (Fig. 43). This season is characterized by a well-defined contrast in water temperature between the western and eastern parts of the sea, and in the south it is weaker than in the north and center of the sea. Thus, at the latitude of Peter the Great Bay, the water temperature in the west is close to 0°, and in the east it reaches 5-6°. This is explained, in particular, by the movement of warm waters from south to north along the eastern edge of the sea.

Spring warming entails a fairly rapid increase in surface water temperature throughout the sea. At this time, the temperature differences between the western and eastern parts of the sea begin to smooth out. In summer, the surface water temperature rises from 18-20° in the north to 25-27° in the south of the sea. Temperature changes across latitude are relatively small. On the western shores, the surface water temperature is 1-2° lower than on the eastern shores, where warm waters spread from south to north.

The vertical distribution of temperature is not the same in different seasons in different areas of the Sea of Japan. In winter, in the northern and northwestern regions of the sea, the water temperature changes only slightly from the surface to the bottom. Its values are close to 0.2-0.4°. In the central, especially southern and southeastern parts of the sea, the change in water temperature with depth is more pronounced. In general, the surface temperature, equal to 8-10°, remains up to horizons of 100-150 m, from which it gradually decreases with depth to approximately 2-4° at horizons of 200-250 m, then it decreases very slowly to 1.0-1 .5° at horizons of 400–500 m; deeper, the temperature drops slightly (to a value of less than 1°), remaining approximately the same to the bottom.

Spring warming begins to create vertical temperature differences in the upper layers, which become sharper over time. In summer, in the north and northwest of the sea, high surface temperature (18-20°) is observed in the layer of 0-10-15 m, from here it sharply decreases with depth, reaching 4° at a horizon of 50 m, then its decrease occurs very slowly to the horizon 250 m, where it is approximately 1°, deeper and to the bottom the temperature does not exceed 1°.

In the central and southern parts of the sea, the temperature decreases quite smoothly with depth and at a horizon of 200 m is approximately 6°, from here it decreases somewhat steeper and at horizons of 250–260 m reaches values of 1.5–2.0°, then its decrease occurs slowly and at horizons of 750–1500 m, in some areas at horizons of 1000–1500 m, it reaches a minimum of 0.04–0.14°, from here the temperature rises towards the bottom to values of 0.28–0.26°, and sometimes and up to 0.33°. The formation of an intermediate layer of minimum temperature values is presumably associated with the immersion of the waters of the northwestern part of the sea, cooled during severe winters. This layer is quite stable and is observed all year round.

The average salinity of the Sea of Japan, equal to approximately 34.09‰, is slightly lower than the same value in the World Ocean, which is due to the isolation of the deep waters of the sea from the Pacific Ocean. Under the influence of surface water exchange with adjacent seas and the Pacific Ocean, precipitation, ice formation and melting, influx of continental waters and other factors, certain features of the distribution of salinity by season in different areas of the sea are formed.

In winter, the highest salinity of the surface layer (approximately 34.5‰) is observed in the south, which is explained by the predominance of evaporation over precipitation here (see Fig. 43, b). The lowest salinity on the surface (about 33.8‰) is observed along the southeastern and southwestern coasts of the sea, where some desalination is caused by heavy precipitation. Over most of the sea, salinity varies from 34.08 to 34.10‰. In spring, in the north and northwest, the desalination of surface waters is caused by melting ice, and in other areas it is associated with increased precipitation. Salinity remains relatively high (34.60–34.70‰) in the south, where at this time the influx of saltier waters through the Korea Strait increases.

In summer, the average salinity on the surface varies from 31.5‰ in the north of the Tatar Strait to 34.5‰ off the coast of the island. Honshu, where at this time evaporation prevails over precipitation. In the central and southern regions of the sea, precipitation significantly exceeds evaporation, which causes desalination of surface waters. By autumn, the amount of precipitation decreases, the sea begins to cool, and therefore the salinity on the surface increases. Over time, a winter distribution of salinity occurs.
The vertical course of salinity is generally characterized by relatively small, but different from season to season and from place to place, changes in its values in depth. In winter, over most of the sea, a uniform salinity from surface to bottom is observed, equal to approximately 34.08–34.10‰ (see Fig. 43, b). Only in coastal waters is there a weakly expressed minimum salinity in the surface horizons, below which the salinity increases slightly and then remains almost the same to the bottom. At this time of year, the vertical change in salinity in most of the sea does not exceed 0.6–0.7‰, and in its central part does not reach 0.1‰.

Spring and further desalination of surface waters begins to form the main features of the summer vertical distribution of salinity. In summer, minimal salinity is observed on the surface as a result of noticeable desalination of surface waters. In the subsurface layers, salinity increases with depth, creating noticeable vertical salinity gradients equal to approximately 0.03‰ in the north and south and about 0.01‰ in the central part of the sea. The maximum salinity at this time occurs at horizons of 50–100 m in the northern and southern regions and at horizons of 500–1500 m in the southern regions. Below the mentioned layers, salinity decreases slightly and remains almost unchanged to the bottom, remaining within the range of 33.93–34.13‰. In summer, the salinity of deep waters is 0.1‰ lower than in winter. An increase in surface salinity in autumn begins the transition to the winter vertical distribution of salinity.

The density of water in the Sea of Japan depends mainly on temperature. Density is highest in winter and lowest in summer. In the northwestern part of the sea, the density is always higher than in the southern and southeastern parts. In winter, the surface density is quite uniform throughout the sea, especially in its northwestern part. In the southeastern regions this homogeneity decreases from north to south. In spring, the uniformity of surface density values is disrupted due to different heating of the upper layer of water. In summer, horizontal differences in surface density are greatest. They are especially significant in the area of mixing waters with different characteristics. The vertical distribution of density is characterized in winter by approximately the same values from the surface to the bottom in the northwestern part of the sea. In the southeastern regions, the density increases slightly at horizons of 50-100 m; deeper, its increase occurs very slightly to the bottom. The maximum density is observed in March.

Reineke Island, Peter the Great Bay

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

The predominance of winds of relatively low strength and even their significant intensification during the passage of cyclones in conditions of sharp interlayering of waters in the north and northwest of the sea allows wind mixing to penetrate here to horizons of about 20 m. In the less stratified waters of the southern and southwestern regions, the wind mixes the upper layers to horizons of 25-30 m. In autumn, stability decreases and winds increase, but at this time of year the thickness of the upper homogeneous layer increases due to density mixing.

Autumn-winter cooling, and in the north, ice formation, cause intense convection in the Sea of Japan. In the northern and northwestern parts of the sea, the rapid autumn cooling of its surface develops powerful convective mixing, which within a short time covers increasingly deeper layers. With the onset of ice formation, this process intensifies and in December convection penetrates to the bottom. At great depths, it extends to horizons of 2000–3000 m, where it is limited by the deep Sea of Japan water. In the southern and southeastern regions of the sea, cooled in autumn and winter to a lesser extent than the mentioned parts of the sea, convection spreads mainly to horizons of 200 m. In areas of sharp changes in depths, convection is enhanced by the sliding of water along slopes, as a result of which density mixing penetrates up to horizons of 300-400 m. Below it is limited by the density structure of the waters, and ventilation of the bottom layers is ensured by a combination of turbulence, vertical movements and other dynamic processes.

Features of the distribution of oceanological characteristics over the sea area and with depth, well-developed mixing, the influx of surface waters from adjacent basins and the isolation of deep sea waters from them form the main features of the hydrological structure of the Sea of Japan. The entire thickness of its waters is divided into two zones: surface (to an average depth of 200 m) and deep (from 200 m to the bottom). The waters of the deep zone are characterized by relatively uniform physical properties throughout their entire mass throughout the year. Water in the surface zone, under the influence of climatic and hydrological factors, changes its characteristics in time and space much more intensively.
In the Sea of Japan, three water masses are distinguished: two in the surface zone - the surface Pacific, characteristic of the southeastern part of the sea, and the surface Sea of Japan, characteristic of the northwestern part of the sea, and one in the deep zone - the deep Sea of Japan water mass. By their origin, these water masses are the result of the transformation of Pacific waters entering the sea.

The surface Pacific water mass is formed mainly under the influence of the Tsushima Current; it has the largest volume in the south and southeast of the sea. As you move north, its thickness and area of distribution gradually decrease and approximately in the region of 48° N. w. due to a sharp decrease in depth, it wedges out into shallow water. In winter, when the Tsushima Current weakens, the northern boundary of the Pacific waters is located at approximately 46-47° N. w.

Surface Pacific water is characterized by high temperatures (about 15-20°) and salinity (34.0-35.5‰). In the water mass under consideration, several layers are distinguished, the hydrological characteristics of which and thickness change throughout the year. The surface layer, where the temperature throughout the year varies from 10 to 25°, and salinity from 33.5 to 34.5‰. The thickness of the surface layer varies from 10 to 100 m. The upper intermediate layer, the thickness of which varies throughout the year from 50 to 150 m. Significant gradients in temperature, salinity and density are noted in it. The lower layer is from 100 to 150 m thick. The depth of occurrence, the boundaries of its distribution, the temperature from 4 to 12°, and the salinity from 34.0 to 34.2‰ change throughout the year. Lower intermediate layer with very slight vertical gradients in temperature, salinity and density. It separates the surface Pacific water mass from the deep Sea of Japan.

winter on the Sea of Japan

As it moves north, Pacific water gradually changes its characteristics under the influence of climatic factors and due to its mixing with the underlying deep Sea of Japan water. As a result of cooling and desalination of Pacific water at latitudes 46-48° N. w. The surface water mass of the Sea of Japan is formed. It is characterized by relatively low temperatures (on average about 5-8°) and salinity (32.5-33.5‰). The entire thickness of this water mass is divided into three layers; superficial, intermediate and deep. As in the Pacific Ocean, in the surface water of the Sea of Japan, the greatest changes in hydrological characteristics occur in the surface layer. The temperature here varies throughout the year from 0 to 21°, salinity from 32.0-34.0‰, and the thickness of the layer from 10 to 150 m or more. In the intermediate and deep layers, seasonal changes in hydrological characteristics are insignificant. In winter, the surface water of the Sea of Japan occupies a larger area than in summer, due to the intensive flow of Pacific waters into the sea at this time.

Deep Sea of Japan water is formed as a result of the transformation of surface waters that descend to depths due to the process of winter convection due to the general cyclonic circulation. The vertical changes in the characteristics of the deep Sea of Japan water are extremely small. The bulk of these waters have a temperature of 0.1-0.2° in winter, 0.3-0.5° in summer; salinity throughout the year is 34.10–34.15‰.
The nature of the circulation of sea waters is determined not only by the influence of the winds acting directly above the sea, but also by the circulation of the atmosphere over the northern part of the Pacific Ocean, since the strengthening or weakening of the influx of Pacific waters depends on this circulation. In summer, the southeast monsoon enhances the circulation of sea waters due to the influx of large amounts of water. In winter, the persistent northwest monsoon prevents the flow of water into the sea through the Korea Strait, causing weakening water circulation. The bottom topography also has a great influence on the circulation of sea waters.

Through the Korea Strait, the waters of the western branch of Kuroshio enter the Sea of Japan and spread in a wide stream to the northeast along the Japanese islands. This flow is called the Tsushima Current. As a result of the influence of the bottom topography, in particular the Yamato Rise, in the central part of the sea the flow of Pacific waters is divided into two branches and a divergence zone is formed, which is especially pronounced in the summer. In this zone, deep waters rise. After skirting the hills, both branches join in an area located northwest of the Noto Peninsula.

At a latitude of 38-39°, a small flow separates from the northern branch of the Tsushima Current to the west, in the area of the Korean Bay, and turns into a countercurrent along the berets of Korea. The bulk of Pacific waters are removed from the Sea of Japan through the La Perouse and Sangarsky straits, while some of the waters, having reached the Tatar Strait, give rise to the cold Primorsky Current, moving south. South of Peter the Great Bay, the Primorsky Current turns east and merges with the northern branch of the Tsushima Current. A small part of the water continues to move south to Korea Bay, where it flows into the countercurrent formed by the waters of the Tsushima Current. Thus, moving along the Japanese Islands from south to north, along the coast of Primorye from north to south, the waters of the Sea of Japan form a cyclonic circulation centered in the northwestern part of the sea. In the center of the gyre, rising waters are also possible.

In the Sea of Japan, two areas of frontal sections are distinguished. The main polar front is formed by the warm and salty waters of the Tsushima Current and the cold, less salty waters of the Primorsky Current. The second front is formed by the waters of the Primorsky Current and coastal waters, which in summer have a higher temperature and lower salinity than the waters of the Primorsky Current. In winter, the polar front passes slightly south of the parallel of 40° N. sh., and near the Japanese Islands the front runs almost parallel to them to the northern tip of the island. Hokkaido. In summer, the front is located approximately the same, shifting somewhat to the south, and off the coast of Japan - to the west. The second front is located near the shores of Primorye, passing parallel to them.

The tides in the Sea of Japan are quite distinct. They are created mainly by the Pacific tidal wave. It enters the sea mainly through the Korean and Sangar Straits, spreads to the northern outskirts of the sea and, in combination with its own tide, determines the main features of this phenomenon here. This sea experiences semidiurnal, diurnal and mixed tides. In the Korea Strait and in the north of the Tatar Strait there are semi-diurnal tides, on the eastern coast of Korea, on the coasts of Primorye, the islands of Honshu and Hokkaido - diurnal tides, in the Peter the Great and Korean Gulfs - mixed.

The nature of the tide corresponds to tidal currents and level fluctuations. In open areas of the sea, semidiurnal tidal currents with speeds of 10–25 cm/s are mainly observed. Tidal currents in the straits are more complex, where they have very significant speeds. Thus, in the Sangar Strait, the speed of tidal currents reaches 100-200 cm/s, in the La Perouse Strait - 50-100 cm/s, in the Korean Strait - 40-60 cm/s.

Tidal level fluctuations in different parts of the sea are far from the same. The greatest level fluctuations are observed in the extreme southern and northern regions of the sea. At the southern entrance to the Korea Strait, the tide reaches 3 m. As you move north, it quickly decreases and already at Busan it does not exceed 1.5 m. In the middle part of the sea, the tides are small. Along the eastern coasts of Korea and Soviet Primorye, up to the entrance to the Tatar Strait, they are no more than 0.5 m. The tides are of the same magnitude off the western coasts of Honshu, Hokkaido and. In the Tatar Strait, the magnitude of the tides is 2.3-2.8 m. The increase in the magnitude of the tides in the northern part of the Tatar Strait is determined by its funnel-shaped shape.

In addition to tidal ones, other types of level fluctuations can be traced in the Sea of Japan. In particular, its seasonal fluctuations are well expressed here. They belong to the monsoon type, since the level experiences seasonal changes simultaneously throughout the year throughout the entire sea area. In summer (August–September) the maximum rise in level is observed on all shores of the sea; in winter and early spring (January–April) the minimum level is observed.

Strong winds caused by the passage of cyclones and especially typhoons over the sea develop very significant waves, while monsoons cause less strong waves. In the northwestern part of the sea, northwestern waves prevail in autumn and winter, and eastern waves prevail in spring and summer. Most often, disturbances of magnitude 1-3 are observed, the frequency of which varies from 60 to 80% per year. In winter, strong waves prevail (6 points or more), the frequency of which is about 10%. In the southeastern part of the sea, thanks to the stable northwest monsoon, waves from the northwest and north develop in winter. In summer, weak, most often southwesterly waves prevail. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m. Giant tsunami waves have been recorded in the Sea of Japan.

The northern and northwestern parts of the sea, adjacent to the mainland coast, are covered with ice annually for 4-5 months, the area of which occupies about a quarter of the entire sea. The appearance of ice in the Sea of Japan is possible as early as October, and the last ice lingers in the north sometimes until mid-June. Thus, the sea is completely ice-free only during the summer months - July, August and September.

The first ice in the sea forms in closed bays and bays of the mainland coast, for example in Sovetskaya Gavan Bay, De-Kastri and Olga Bays. In October-November, ice cover mainly develops within bays and bays, and from late November to early December, ice begins to form in the open sea. At the end of December, ice formation in coastal and open sea areas extends to Peter the Great Bay. Fast ice is not widespread in the Sea of Japan. It forms first in the bays of De-Kastri, Sovetskaya Gavan and Olga; in the bays of Peter the Great Bay and Posyet, fast ice appears after about a month.

Every year, only the northern bays of the mainland coast freeze completely. South of Sovetskaya Gavan, the fast ice in the bays is unstable and can break up repeatedly during the winter. In the western part of the sea, floating and stationary ice appears earlier than in the eastern part, spreads further to the south and is more stable than at the same latitudes in the eastern part of the sea. This is explained by the fact that the western part of the sea in winter is under the predominant influence of cold and dry air masses spreading from the mainland. In the east of the sea, the influence of these masses weakens significantly, at the same time the role of warm and humid sea masses increases. The ice cover reaches its greatest development around mid-February. From February to May, conditions favorable for ice melting (in situ) are created throughout the sea. In the eastern part of the sea, ice melting begins earlier and occurs more intensely than at the same latitudes in the west. The ice cover in the Sea of Japan experiences significant changes from year to year. There may be cases when the ice cover in one winter is twice or more greater than the ice cover in another.

Hydrochemical conditions. The natural features of the Sea of Japan and, above all, the isolation of the deep part of its basin from the Pacific Ocean form the distinctive features of the hydrochemical conditions in it. They manifest themselves primarily in the distribution of oxygen and nutrients throughout the sea and with depth. In general, the sea is rich in dissolved oxygen. In the western part, its concentration is slightly higher than in the eastern part, which is explained by the lower water temperature and the relative richness of phytoplankton in the western regions of the sea. Oxygen content decreases with depth. However, the Sea of Japan, unlike other seas of the Far East, is characterized by a high oxygen content (up to 69% saturation) in the bottom waters and the absence of an oxygen minimum in the deep layers. This is due to intense vertical water exchange within the sea itself.

Economic use. The Sea of Japan is characterized by the high development of two sectors of the national economy: fishing with a wide variety of fishing objects and maritime transport with a developed transportation network. Fisheries combine fishing (sardine, mackerel, saury and other species) and the extraction of non-fish objects (sea shellfish - mussels, scallops, squid; algae - kelp, seaweed, ahnfeltia). "Soviet Union". Although it fishes in Antarctica, its products go to fisheries enterprises in Vladivostok. In the Sea of Japan, active work has begun on mariculture breeding - the most promising method of using marine biological resources.

On the shores of the Sea of Japan, in Vladivostok, the Trans-Siberian Railway ends. The most significant transshipment transport hub is located here, where cargo is exchanged between rail and sea transport. Further along the Sea of Japan, cargo travels on sea vessels to various foreign and Soviet ports, just as they arrive from other ports to the ports of the Sea of Japan: Sovetskaya Gavan, Nakhodka, Vanino, Aleksandrovsk-on-Sakhalin, Kholmsk. These ports provide maritime transport not only in the Sea of Japan, but also beyond it. Recently, the ports of Vanino and Kholmsk on Sakhalin have been connected by a sea ferry, which has further strengthened the transport role of the Sea of Japan.

Research in the Sea of Japan has been carried out since ancient times, so it is one of the most studied seas not only of the Far East, but of our entire country. Nevertheless, there are still many unresolved problems in all oceanological aspects. With regard to hydrological problems, the most significant are: the study of the quantitative characteristics of water exchange through the straits, the formation of thermohaline conditions in the deep layers of the sea, vertical movements of water, patterns of ice drift; development of forecasts for the passage of typhoons and tsunamis. All these are just examples of the main directions in which research in the Sea of Japan is being and will be carried out with the aim of its further development.

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SOURCE OF INFORMATION AND PHOTO:
Team Nomads
http://tapemark.narod.ru/more/18.html
Melnikov A.V. Geographical names of the Russian Far East: Toponymic Dictionary. — Blagoveshchensk: Interra-Plus (Interra+), 2009. — 55 p.
Sovetov S.A., Sea of Japan // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional). - St. Petersburg, 1890-1907.
Shamraev Yu. I., Shishkina L. A. Oceanology. L.: Gidrometeoizdat, 1980.
The Sea of Japan in the book: A. D. Dobrovolsky, B. S. Zalogin. Seas of the USSR. Publishing house Moscow. University, 1982.
Japanese Sea. Ministry of Foreign Affairs of Japan.
Wikipedia website.
Magidovich I. P., Magidovich V. I. Essays on the history of geographical discoveries. - Enlightenment, 1985. - T. 4.
http://www.photosight.ru/
photo: V. Plotnikov, Oleg Slor, A. Marakhovets, A. Shpatak, E. Efremov.

The Sea of Japan is a marginal sea of the Pacific Ocean and is limited by the coasts of Japan, Russia and Korea. The Sea of Japan is connected 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, the average depth is 1361 m. The northern border of the Sea of Japan runs along 51 ° 45 "N latitude (from Cape Tyk on Sakhalin to Cape Yuzhny on the mainland). The southern border runs from the island of Kyushu to the Goto Islands and from there to Korea [Cape Kolcholkap (Izgunov)]

The Sea of Japan has an almost elliptical shape with the major axis in the direction from southwest to northeast. 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 Kyushu Island), Ulleungdo and Takashima off the east coast of Korea, Oki and Sado off the west coast of Honshu Island (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. w. into two parts: northern and southern.

The northern part has a relatively flat bottom topography and is characterized by an overall smooth slope. The maximum depth (4224 m) is observed in the area of 43°00"N, 137°39"E. d.
The bottom topography 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
jars separated by deep grooves. This is the Yamato Bank, opened in 1924, in the area of 39°N, 135°E. etc., and the Shunpu Bank (also called the Northern Yamato Bank), opened in 1930 and located approximately 40° N. latitude, 134° east. d. The smallest depths of the first and second banks are 285 and 435 m, respectively. A depression with a depth of more than 3000 m was discovered between the Yamato Bank and the island of Honshu.

Hydrological regime

Water masses, temperature and salinity. The Sea of Japan can be divided into two sectors: warm (from Japan) and cold (from Korea and Russia (Primorsky Territory). The boundary between the sectors is the polar front, running approximately along the parallel of 38-40 ° N, i.e. almost along the same latitudes along which the polar front passes in the Pacific Ocean east of Japan.

Water masses

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

The surface water mass exhibits the largest fluctuations in temperature and salinity depending on the season and region. 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 island. Hokkaido. In the coastal areas of Korea and Primorye, changes in salinity are small (33.7-34 ppm). The intermediate water mass, which lies below the surface water in the warm sector of the Sea of Japan, has high temperature and salinity. It is formed in the intermediate layers of Kuroshio west of Kyushu Island and enters the Sea of Japan from there during the period of early winter to early summer.

However, based on 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 vertical temperature - 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 to the cold sector; 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 industrial. in the cold. The highest salinity values are observed here at all depths - from the surface to the bottom.

The deep water mass, usually called 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 increases slightly due to adiabatic heating. At the same horizon, a decrease in oxygen content to a minimum is observed, and therefore it is more logical to consider waters above 1500 m as deep, and below 1500 m as bottom. Compared to 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 the 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 increases to approximately 34.0 ppm.

Sometimes the low-salinity surface waters of the cold sector (1-4° C, 33.9 ppm) wedge into the polar front and deepen in a southerly direction, going under the intermediate waters of the warm sector. This phenomenon is similar to the penetration of subarctic intermediate water below the warm Kuroshio layer in the Pacific Ocean in the area 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 melting ice. These less saline waters mix with surrounding waters and the overall salinity of the surface waters of the Sea of Japan decreases. Additionally, 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 clearly defined upper thermocline layer that separates the surface waters from the underlying intermediate waters. The upper thermocline layer is located in the summer season at a depth of 25 m. In autumn, heat is transferred from the sea surface to the atmosphere. Due to mixing with underlying water masses, the temperature of surface waters decreases and their salinity increases. The resulting intense convection leads to a deepening of the upper thermocline layer to 25–50 m in September and 50–100 m in November. In autumn, intermediate waters of the warm sector are characterized by a decrease in salinity due to the influx of waters of 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 upper thermocline layer disappears completely due to the mixing of overlying and underlying waters. Therefore, in autumn and spring there is only an upper homogeneous layer of water and an underlying cold layer, separated by a layer of 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 off the coast of the island 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 surface layer temperature off the Korean coast 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. Due to the low temperatures characteristic of most of the Sea of Japan at fairly large depths, the waters of the Tsushima Current are greatly cooled as they move north.

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

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

Color and transparency

The color of the water of the Sea of Japan (according to the color scale) in the warm sector is bluer than in the cold sector, corresponding to the region of 36-38° N. latitude, 133-136° east. etc. 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, the sea water has a greenish color. Transparency (by the white disk) in the Tsushima Current region is more than 25 m. In the cold sector it sometimes drops to 10 m.

Currents of the Sea of Japan

The main current of the Sea of Japan is the Tsushima Current, which originates in the East China Sea. It is strengthened mainly by the branch of the Kuroshio Current, going to the SOUTHWEST of the island. Kyushu, as well as partially by coastal runoff from China. The Tsushima Current contains surface and intermediate water masses. The current enters the Sea of Japan through the Korea Strait and heads along the northwestern coast of Japan. There, a branch of the warm current, called the East Korean Current, separates from it, which goes in the north, to the coast of Korea, to the Korean Gulf and Ulleungdo Island, then turns to the SE and connects with the main flow.

The Tsushima Current, about 200 km wide, washes the shores of Japan and goes further to the NE at a speed of 0.5 to 1.0 knots. Then it divides into two branches - the warm Sangar Current and the warm La Perouse Current, which respectively exit 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 east and go, respectively, near the eastern coast of the island of Honshu and the northern coast of the island of Hokkaido.

There are three cold currents in the Sea of Japan: the Liman current, moving at low speed to the southwest in the area north of the Primorsky Territory, the North Korean current, going south in the Vladivostok area to eastern Korea, and the Primorsky current, or the 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, contain clearly defined layers of surface and intermediate water masses. There is a clear boundary of the “polar” front between the warm and cold currents.

Because the Tsushima Current contains surface and intermediate water masses that 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 speed is almost constant to a depth of 25 m, 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 flow rate of the Kuroshio Current.

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 Korean Current, which is the strongest, has a speed of 0.5 knots. The width of this current is 100 km, thickness - 50 m. Basically, cold currents in the Sea of Japan are much weaker than warm ones. The average speed of the Tsushima Current passing through the Korean Strait is lower in winter, and increases to 1.5 knots in summer (in August). For the Tsushima Current, interannual changes are also observed, with a clear period of 7 years being distinguished. The flow of water into the Sea of Japan mainly occurs through the Korea Strait, since the inflow through the Tartary Strait is very insignificant. The flow of water from the Sea of Japan occurs through the Tsugaru (Sangara) and La Perouse Straits.

Tides and tidal currents

Tides are low for the Sea of Japan. While off the coast of the Pacific Ocean the tide is 1-2 m, in the Sea of Japan it reaches only 0.2 m. Slightly higher values are observed off the coast of the Primorsky Territory - up to 0.4-0.5 m. In the Korean and Tatar Territories In the straits, the tide increases, reaching more than 2 m in some places.

Tidal waves propagate at right angles to these cotidal lines. 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 amphidromy point is located in the Korea Strait. Since the total cross-sectional area of the La Perouse and Tsugaru Straits is only 1/8 of the cross-sectional area of the Korea Strait, and the cross-section of the Tartary Strait is generally insignificant, the tidal wave comes here from the East China Sea mainly through the East 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 eastward Tsushima Current sometimes reaches 2.8 knots. In the Tsugaru (Soigarsky) Strait, a tidal current of the diurnal type predominates, but the magnitude of the semidiurnal tide is greater here.

There is a clear diurnal inequality in tidal currents. 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 diurnal inequality here. In the La Perouse Strait, the current is directed mainly to the east; its speed sometimes exceeds 3.5 knots.

Ice Conditions

Freezing of the Sea of Japan begins in mid-November in the area of the Tatar Strait and in early December in the upper reaches of Peter the Great Bay. In mid-December, areas near the northern part of Primorsky Krai and Peter the Great Bay freeze. In mid-December, ice appears in the coastal areas of Primorsky Krai. In January, the area of ice cover increases further from the coast towards the open sea. With the formation of ice, navigation in these areas naturally becomes difficult or stops. The freezing of the northern part of the Sea of Japan is somewhat delayed: it begins in early to mid-February.

Ice melting begins in areas furthest 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 in Vladivostok resumes. The last ice in the Tartary Strait is observed in early to mid-May. The period of ice cover along the coast of the Primorsky Territory is 120 days, and near the De-Kastri harbor in the Strait of Tartary - 201 days. There is not much ice observed along the northern coast of the DPRK. On 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 Sea of Japan basin are characterized by many submarine canyons. On the mainland side, these canyons stretch to depths of more than 2000 m, and on the side of the Japanese Islands only to 800 m. The mainland shoals of the Sea of Japan are poorly developed, the edge runs at a depth of 140 m on the mainland side and at a depth of more than 200 m. Yamato Bank and other banks The Sea of Japan is composed of bedrock consisting of Precambrian granites and other Paleozoic rocks and overlying Neogene igneous and sedimentary rocks. According to paleogeographic studies, the southern part of the modern Sea of Japan was probably dry land in the Paleozoic and Mesozoic and during most of the Paleogene. It follows from this that the Sea of Japan was formed during the Neogene and early Quaternary periods. The absence of a granite layer in the earth's crust of the northern part of the Sea of Japan indicates the transformation of the granite layer into a basalt layer due to basification, accompanied by subsidence of the earth's crust. The presence of “new” oceanic crust here can be explained by the stretching of continents accompanying the general expansion of the Earth (Egayed’s theory).

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

The Sea of Japan currently has a connection with the Pacific Ocean and the surrounding marginal seas through the Korean, Tsugaru (Saigarsky), La Perouse and Tatar straits. However, the formation of these four straits occurred during very recent geological periods. The oldest strait is the Tsugaru (Sangara) Strait; it already existed during the Wisconsinian glaciation, although it may have been filled with ice several times after that 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 southern elephants to the Japanese islands took place; 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

Part of the Pacific Ocean basin and separated from it by Sakhalin and the Japanese Islands, the Sea of Japan splashes off the coasts of Russia, Japan, China and Korea. The climatic conditions here are harsh. In the northern and western parts, ice appears already by the third ten days of November, and in some years the ice formed by the 20th of October. Temperatures in these areas can drop to -20 degrees Celsius. Ice melting begins in March and continues until the end of April. There were years when the sea surface was completely cleared of ice cover only in June.

However, in summer the Sea of Japan in its southern borders pleases with a water temperature of +27 (even higher than in the Aegean Sea!). In the northern part, the water temperature is about +20 degrees, the same as in May in the south of Greece. A characteristic feature of the Sea of Japan is its extremely unstable weather. In the morning the sun can shine brightly, and by lunchtime a strong wind rises and a storm with thunderstorms begins. This happens especially often in the fall. Then during a storm the wave can reach 10-12 meters in height.

The Sea of Japan is rich in fish. Mackerel, flounder, herring, saury, and cod are caught here. But the most popular, of course, is pollock. During spawning, coastal waters literally boil with a huge amount of this fish. They also produce shrimp and seaweed, which has become very popular in recent years, or rather, in addition, in the Sea of Japan you can find squid and octopus, which can be found weighing up to 50 kilograms. And the huge eels found here, also called herring kings, were in years past mistaken for underwater monsters.

Holidays on the Sea of Japan will appeal more to those who are not looking for noisy entertainment. The beauty of the reefs and crystal clear waters are ideal for snorkeling enthusiasts. Equipment here can be obtained from special diving centers. They also give it out at many tourist centers.

The only thing divers need to take into account is that the water temperature drops sharply with depth. In the northern waters, already at a depth of 50 meters it reaches only +4 degrees Celsius. In the southern part, the temperature reaches this level at a depth of approximately 200 meters. And a little deeper it equals zero.

Those who choose the Sea of Japan for vacation can not only go diving, but also make interesting forays into the Ussuri taiga. It keeps a lot of secrets and mysteries, so you won’t be bored here. Just look at the footprint of a giant left in a stone. Its length is incredible for our perception - it is one and a half meters! The Dragon Park is also of great interest. Local residents are sure that the unusual pile of huge boulders was once created by aliens. On the sea coast near the city of Nakhodka there are two hills called Brother and Sister. According to legend, they were made by the Titans as a gate through which the Prince of Light would one day come to Earth. For lovers of everything mysterious and unusual, a holiday on the Sea of Japan will seem like paradise. And the exotic beauty of these places will remain in the memory for a long time.

The Inland Sea of Japan splashes between Kyushu and Shikoku. It is small, only 18 thousand square kilometers, but is the most important transport artery between these islands. On its banks rise Hiroshima, Fukuyama, Osaka, Niihama and other major industrial centers of Japan. This sea is considered warm. The water temperature here, even in the winter months, never falls below +16 degrees Celsius, and in the summer it rises to +27. Tourism on this small sea is very well developed. Every year thousands of people from all over the world come here to admire the magnificent landscapes, visit ancient samurai shrines, and get acquainted with the original Japanese culture.

Seas of Russia - Sea of Japan. Sea of Japan ~ Seas and Oceans Warm current in the Sea of Japan

Bottom relief

Climate

Hydrology

Water temperature and salinity

Water circulation and currents

Ice cover

Economic importance

Sailing

Bottom relief

Climate and hydrological regime

Flora and fauna

Economic importance

Ecology

Hydrological regime

Currents of the Sea of Japan

Tides and tidal currents

Ice Conditions

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Bottom relief

Climate

Hydrology

Water temperature and salinity

Water circulation and currents

Ice cover

Economic importance

Sailing

Bottom relief

Climate and hydrological regime

Flora and fauna

Economic importance

Ecology

Hydrological regime

Currents of the Sea of ​​Japan

Tides and tidal currents

Ice Conditions

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Currents of the Sea of Japan