Sea of ​​Japan border. Japanese Sea. Tides and tidal currents

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. Having skirted 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.

Strong winds caused by the passage of cyclones and especially typhoons over the sea develop very significant waves, while monsoons cause less strong waves. In the northwestern part of the sea, northwestern waves predominate in autumn and winter, and eastern waves prevail in spring and summer. Most often, disturbances with a force of 1-3 points 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. 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.

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 - 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 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.

The northern and western parts of the Sea of ​​Japan/East Sea are much colder than the eastern and southern parts. The temperature difference ranges from −20 °C to +27 °C.

Therefore, in autumn there are typhoons and hurricanes in these latitudes. Of course, the flora and fauna of these areas are very different. Moreover, some animals migrate from north to south at unfavorable times of the year.

The Sea of ​​Japan/East Sea is recognized as the richest sea in our country in terms of the number of animal and plant species. There are 225 species of algae alone.

The most famous is, of course, kelp. It is so actively used in cooking and the cosmetics industry that it is collected not only in the natural environment, but also grown on plantations.

Kamchatka crab is also well known to Russians. Its distribution area stretches from the Bering Sea to the Korean Sea and the American coast, at a depth of up to three hundred meters. The crab grows to enormous sizes, with a claw span of up to one and a half meters. The main fishery is located off the coast of Kamchatka, where its population is especially numerous.

There are quite a few species of shellfish in the Sea of ​​Japan/East Sea. They are natural water filters, live about a hundred years and grow up to twenty centimeters in length. And giant ones - up to seventy. Their colonies live at depths of up to seven meters and easily survive the winter under the ice.

Mussels contain many useful substances and are very nutritious. Therefore, they are the subject of fishing and food not only for humans, but also for many species of starfish and fish. Since they lead a sedentary lifestyle, their fertility saves them from complete extinction; at the end of summer they release more than a million eggs each. However, mollusks have the unpleasant feature of accumulating substances that they pass through with water. In environmentally unfavorable areas, their use can be hazardous to health.

Steller sea lion is a mammal of the Sea of ​​Japan/East Sea.

Whaling, due to its past intensity, is prohibited in the Sea of ​​Japan/East Sea. Therefore, the mammal population gradually began to recover and is currently home to about thirty species of seals, dolphins and whales. All species of minke whales and many varieties of odontocetes are common in the Sea of ​​Japan. For example, beluga whale and killer whale.

Six species of seals live in this region. The most famous is the northern fur seal.

Almost two hundred species of fish out of nine hundred existing are caught in Primorye. These are mackerel, flounder and many other species known to the general consumer.

There are twelve sharks in the Sea of ​​Japan/East Sea that are not dangerous to humans. Rather, on the contrary, the Japanese love for shark fin soup has greatly reduced the number of katran fish. Rhopilema jellyfish is also considered an expensive and sophisticated delicacy. In addition to its culinary value, in China it is used to prepare medicines. For example, for the treatment of tracheitis.

For example, in the Red Sea, surrounded by deserts, salinity reaches 41%. In most of the world's seas, due to river runoff, the salinity is less than that of the ocean. The waters of the Sea of ​​Japan from the surface to the greatest depths are highly saturated with free oxygen. In most areas, the waters of the Sea of ​​Japan are blue-green. In the southeast, in the zone of the Tsushima Current, the color of the water is intensely blue, and in the north, in the Tatar Strait, it is greenish. The coastal waters of Korea, Soviet Primorye, Sakhalin and Hokkaido are known for the abundance of kelp (seaweed), a type of brown algae. Animal world. The fauna of the Sea of ​​Japan is abundant and diverse: in terms of the number of species, it significantly exceeds the plant world. Only here the southern fish go a little further north compared to the western part of the sea. This applies to fish living in the surface layers of the open sea; they are carried north by the Tsushima Current. P. Yu. Schmidt also considers the cooling of the waters of the Sea of ​​Japan to be the main reason for the disappearance of the Far Eastern sardine. In support of his view, P. Yu. Schmidt in his book “Fishes of the Pacific Ocean” cites maps of water temperatures in the Sea of ​​Japan compiled by A. M. Batalin.

Marine life of the Sea of ​​Japan

About 30 species of seals, dolphins and whales live in the Sea of ​​Japan. There is no permanent whale fishery here. But during the Second World War, minke whales were caught in Peter the Great Bay. All species of this family are present in the Sea of ​​Japan. Among them: sei whale, blue whale, gray whale, humpback whale, southern right whale, fin whale and minke whale. Among them: sea hare, sea lion, northern fur seal, akiba, sealed seal and lionfish.

There are 12 species of sharks living in the Sea of ​​Japan, the most common of which is the Katran shark. The sharks here are not big and are not dangerous to humans.

The Sea of ​​Japan/East Sea is recognized as the richest sea in our country in terms of the number of animal and plant species. The main fishery is located off the coast of Kamchatka, where its population is especially numerous. There are quite a few species of shellfish in the Sea of ​​Japan/East Sea. There are twelve sharks in the Sea of ​​Japan/East Sea that are not dangerous to humans. It is impossible to imagine Primorye, like Japanese cuisine, without shrimp and sea cucumbers.

Tides in the Sea of ​​Japan

The climate of the Sea of ​​Japan is temperate, monsoonal. Surface currents form a gyre, which consists of the warm Tsushima Current in the east and the cold Primorsky Current in the west. In the Sea of ​​Japan, the ice cover reaches its maximum development in mid-February. The underwater world of the northern and southern regions of the Sea of ​​Japan 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.

The Sea of ​​Japan is the warmest of the Far Eastern seas of Russia. In Kronstadt, for the first time in History, Ricord set up the first minefield in history, which saved the lives of many Russian sailors. The most “populated” place is Peter the Great Bay due to its unique natural conditions; warm and cold currents occur in the bay. There are a lot of crabs off the coast of Kamchatka, and the Kamchatka crab is a commercial object. Ropilema. Blue or brown jellyfish with an umbrella up to 60 cm, they are often found in the warm waters of Peter the Great Bay, their burn is not severe, but can cause a severe allergic reaction.

The sea washes the shores of Russia, North and South Korea, as well as Japan. The East China and Yellow Seas - the Korean Straits. There are bays - East Korean and Peter the Great. The Sea of ​​Japan, like the Bering Sea and the Sea of ​​Japan, is quite productive in the development of plankton.

Water characteristics

The northern part is characterized by an icy surface surface, while in the southern part the approximate temperature is 15 degrees. The transparency of water depends on its temperature.

A characteristic of the Sea of ​​Japan is also the presence of small islands such as Popov, Okushiri, Russky, Oshima, Putyatin, Sado and others. The waters form bays, such as Sovetskaya Gavan, Ishikari, and Peter the Great. The fishery resources of the Sea of ​​Japan are highly productive and diverse, including a large number of fish species. Its waters accommodate more than 3,000 inhabitants. Studies of the water of the Sea of ​​Japan show quite high pollution. The information provided will help to assess the resources of the Sea of ​​Japan, study its characteristics, recognize its inhabitants, and clarify environmental aspects.

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. 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. They are created mainly by the Pacific tidal wave entering the sea through the Korea and Sangar Straits. In the Sea of ​​Japan, surge level fluctuations are 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.

Salinity 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 entire thickness of this water mass is divided into three layers: surface, intermediate and deep. 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 structural features of the waters of the Sea of ​​Japan are well illustrated by the distribution of oceanological characteristics in it. The vertical variation of salinity is generally characterized by small changes in its values ​​along the depth.

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. 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 northern and western ones are characterized by -20°C, the eastern and southern ones - +5°C. August has been considered a warm month for several years now. An interesting fact is that ice initially appears in places where fresh water is present in the Sea of ​​Japan, and only then does it spread to other parts of the reservoir. Thawing often begins in March. The depth of the Sea of ​​Japan facilitates the rapid process of getting rid of ice. It could start at the end of April.

110 points. Please help. About the Sea of ​​Japan according to this plan. I beg you.

The biological resources of the Sea of ​​Japan in different parts have their own characteristic features. Near the Far East there are plants and animals inhabiting warm-water and temperate climates. Here you can see squid and octopus.

But the inhabitants of colder seas can only be seen by people who are seriously interested in diving. Well, or already fishermen. Therefore, we will personally look at the postcards about the Sea of ​​Japan. Nutrients enter the predator’s body, and another open shell remains at the bottom of the sea. Even a very small scallop can move up to 25 liters of water per hour. Here lies a scallop at the bottom. Noticing danger, he releases an ink cloud, and he runs away and takes on the color of the surrounding area.

The Japanese side, in turn, shows that the name “Sea of ​​Japan” appears on most maps and is generally accepted. The most noticeable capes are Lazareva, Peschany, Povorotny, Gromova, Pogibi, Tyk, Korsakova, Krillon, Soya, Nosyappu, Tappi, Nyuda and some others. 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. Continental flow into the Sea of ​​Japan is approximately 210 km3/year and is fairly evenly distributed across months. 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. 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.

Although the reservoir belongs to the ocean basin, it is well isolated from it. They could be called typical, if not for the fact that the reservoir washes several states at once. They have different policies for the protection of sea waters, so the influence on the part of people also differs.

But Japan itself does not agree with this; they claim that this name is generally accepted. The coastline is slightly indented, the outlines of Sakhalin Island are especially simple.

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Starfish are often found, the diameter of which can be up to 35 cm. They are capable of moving up to 10 cm per second. Mussels that purify water like a filter. Giant oysters, which can sometimes reach up to 70 cm in length, thrive both under the ice and during low tides in summer. A huge mass of salt water, beautiful views, rich flora and fauna, hundreds of beautiful islands - this is all called the Atlantic Ocean. The collection of all the largest bodies of water on Earth. Something we simply couldn't live without. The World Ocean includes all four oceans of our planet.

According to icing conditions, the Sea of ​​Japan is divided into regions.

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. In general, 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

The Sea of ​​Japan is considered one of the largest and deepest seas in the world. It is a marginal sea of ​​the Pacific Ocean.

Origin

The first information about this sea was received from Chinese sources in the 2nd century BC. Historically, it is believed that this reservoir was formed as a result of the melting of a glacier and rising water levels in the world's oceans.

Historical events

In the 14th-16th centuries, pirates seized power at sea. All maritime trade was under their control. From 1603 to 1867, the Sea of ​​Japan was one of the busiest transport links and the main route of entry for Dutch and Korean embassies.

Sea of ​​Japan on the map photo

The Sea of ​​Japan witnessed the Russo-Japanese War (1901-1902). Today, the Sea of ​​Japan is an important domestic and international transport artery.

Characteristic

Main characteristics of the Sea of ​​Japan:

• Area 1,062,000 square km
• Average sea depth: 1536 m.
• Greatest depth: 3742 m.
• Salinity: 34-35 ‰.
• Length: from north to south 2,255 km, from west to east about 1,070 km.
• In winter, part of the Sea of ​​Japan freezes - the Russian coastal side, but the ice can break up periodically;
• Average annual temperature: in the north 0-12C, in the south 17-26C.

shore of the Sea of ​​Japan photo

Currents

The main current of the Sea of ​​Japan is the Tsushima, whose width is approximately 200 km. This current contains surface and intermediate water masses. In addition, the following cold currents are observed in the Sea of ​​Japan:

• Limanskoye, moving at low speed to the southwest;
• North Korean, going south;
• Coastal, or cold current, going to the central part.

Japanese Sea. Primorsky Krai photo

These cold currents form a counterclockwise circulation. The warm Kuroshio Current prevails in the southern part of the sea.

What rivers flow into

Few rivers flow into the Sea of ​​Japan, most of them are mountainous. Let us note the largest of them:

• Partisan;
• Tumnin;
• Samarga;
• Rudnaya.

Where does the Sea of ​​Japan flow into?

Sea waters enter through the straits:

• through the Nevelsky Strait to the Sea of ​​Okhotsk;
• through the Sangar Strait to the Pacific Ocean;
• through the Korea Strait into the East China Sea.

Japanese Sea. storm photo

Climate

The climate of the sea is monsoon, temperate. The western and northern parts of the sea are much colder than the southern and eastern. The temperature difference reaches +27 C. Hurricanes and typhoons often pass over the sea surface.

Despite the fact that the sea is separated from the ocean by the Japanese islands and Sakhalin, storms and hurricanes often rage in the northern part of the sea, especially in autumn. Such exposure can last up to three days, and the waves reach 12 meters in height. The Siberian anticyclone brings such weather. For this reason, the Sea of ​​Japan is not very calm for shipping.

Japanese Sea. port of Vladivostok photo

In November, the northern part of the sea is covered with ice, and in March-April the ice breaks up. In summer the weather is cloudy and weak monsoon winds from the southeast prevail.

Relief

The bottom topography of the Sea of ​​Japan is divided into:

• the northern part (a wide trench that narrows and rises to the north);
• the central part (a deep closed basin, elongated in a northeast direction);
• the southern part (the terrain is complex, alternating shallow water with trenches).

The shores of this sea are mostly mountainous. Low-lying coastlines are extremely rare. The coastline is quite flat on Sakhalin. The shores of Primorye are more rugged.

underwater world of the Sea of ​​Japan photo

Cities and ports

Let us note the more significant Russian port cities located in the Sea of ​​Japan:

• Vladivostok;
• Nakhodka;
• Oriental;
• Sovetskaya Gavan;
• Vanino;
• Shakhtersk

Flora and fauna

Brown algae and kelp grow abundantly along the seashores. The Sea of ​​Japan is very rich in fish fauna due to the abundance of oxygen and food. Approximately 610 species of fish live here. The main types of fish fauna are:

• In the southern part of the sea - anchovy, sardine, horse mackerel, mackerel.
• In the northern regions - flounder, herring, salmon, greenling, mussels, saury, hammerfish, tuna.

Fishing in the Sea of ​​Japan lasts all year round. This region is home to 6 species of seals, 12 species of sharks that are not dangerous to humans, squid and octopuses.

Few people know the following interesting facts about the Sea of ​​Japan:

• Residents of North Korea call this sea the Korean East Sea;
• Residents of South Korea - the East Sea.
• Here you can meet representatives of 31 orders of fish out of 34 orders existing in the world;
• The Sea of ​​Japan leads in fish diversity among all the seas of the Russian Federation;
• A small jellyfish lives in the algae of the sea, capable of infecting the central nervous system, and with repeated contact its poison can be fatal. There are no famous resorts here, but the Sea of ​​Japan is very important for the trade and economy of several countries, including Russia.