Seas of Russia - Sea of ​​Okhotsk. Sea of ​​Okhotsk: resources, description, features and interesting facts

The Sea of ​​Okhotsk protrudes quite deeply into the land and extends noticeably from southwest to northeast. It has shorelines almost everywhere. It is separated from the Sea of ​​Japan by about. Sakhalin and the conventional lines of Cape Sushchev - Cape Tyk (Nevelskoy Strait), and in the La Perouse Strait - Cape Soya - Cape Crillon. The southeastern border of the sea goes from Cape Nosappu (Hokkaido Island) and through the Kuril Islands to Cape Lopatka (Kamchatka Peninsula).

The Sea of ​​Okhotsk is one of the largest and deepest seas in the world. Its area is 1,603 thousand km 2, volume - 1,316 thousand km 3, average depth - 821 m, greatest depth - 3,521 m.

The Sea of ​​Okhotsk belongs to the marginal seas of the mixed continental-ocean type. It is separated from the Pacific Ocean by the Kuril ridge, which has about 30 large and many small islands and rocks. The Kuril Islands are located in a belt of seismic activity, which includes more than 30 active and 70 extinct volcanoes. Seismic activity occurs on the islands and underwater. In the latter case, tsunami waves are often formed. In the sea there is a group of Shantarsky islands, the Spafaryev, Zavyalov, Yamsky islands and the small island of Jonah - the only one of all that is remote from the coast. Although the coastline is long, it is relatively weakly indented. At the same time, it forms several large bays (Aniva, Terpeniya, Sakhalinsky, Akademii, Tugursky, Ayan, Shelikhova) and bays (Udskaya, Tauyskaya, Gizhiginskaya and Penzhinskaya).

The Nevelskoy and La Perouse straits are relatively narrow and shallow. The width of the Nevelskoy Strait (between capes Lazarev and Pogibi) is only about 7 km. The width of the La Perouse Strait is 43-186 km, depth is 53-118 m.

The total width of the Kuril Straits is about 500 km, and the maximum depth of the deepest of them, the Bussol Strait, exceeds 2300 m. Thus, the possibility of water exchange between the Seas of Japan and the Sea of ​​Okhotsk is incomparably less than between the Sea of ​​Okhotsk and the Pacific Ocean.

However, even the depth of the deepest of the Kuril Straits is significantly less than the maximum depth of the sea, and therefore the Kuril ridge is a huge threshold that fences off the sea depression from the ocean.

The most important for water exchange with the ocean are the Bussol and Krusenstern straits, since they have the largest area and depth. The depth of the Bussol Strait was indicated above, and the depth of the Kruzenshtern Strait is 1920 m. Of less importance are the Frieza, Fourth Kurilsky, Ricord and Nadezhda straits, whose depths are more than 500 m. The depths of the remaining straits generally do not exceed 200 m, and their areas are insignificant.

On distant shores

The shores of the Sea of ​​Okhotsk in different areas belong to different geomorphological types. For the most part, these are abrasive shores modified by the sea, and only in Kamchatka and Sakhalin are there accumulative shores. The sea is mostly surrounded by high and steep shores. In the north and northwest, rocky ledges descend directly to the sea. Along the Sakhalin Bay the shores are low. The southeastern coast of Sakhalin is low, and the northeastern coast is low. The shores of the Kuril Islands are very steep. The northeastern coast of Hokkaido is predominantly low-lying. The coast of the southern part of Western Kamchatka has the same character, but the shores of its northern part rise somewhat.

Shores of the Sea of ​​Okhotsk

Bottom relief

The bottom topography of the Sea of ​​Okhotsk is varied. The northern part of the sea is a continental shelf - an underwater continuation of the Asian continent. The width of the continental shelf in the area of ​​the Ayano-Okhotsk coast is approximately 185 km, in the area of ​​Udskaya Bay - 260 km. Between the meridians of Okhotsk and Magadan, the width of the shoal increases to 370 km. On the western edge of the sea basin is the island sandbank of Sakhalin, on the east - the sandbank of Kamchatka. The shelf occupies about 22% of the bottom area. The rest, most (about 70%) of the sea is located within the continental slope (from 200 to 1500 m), on which individual underwater hills, depressions and trenches are distinguished.

The deepest, southern part of the sea (more than 2500 m), which is a section of the bed, occupies 8% of the total area of ​​the sea. It stretches as a strip along the Kuril Islands and gradually narrows from 200 km against the island. Iturup up to 80 km against the Krusenstern Strait. Great depths and significant bottom slopes distinguish the southwestern part of the sea from the northeastern part, which lies on the continental shallows.

Of the large elements of the bottom relief of the central part of the sea, two underwater hills stand out - the Academy of Sciences and the Institute of Oceanology. Together with the protrusion of the continental slope, they divide the sea basin into three basins: the northeastern - TINRO depression, the northwestern - Deryugin depression and the southern deep-sea - Kuril depression. The depressions are connected by gutters: Makarov, P. Schmidt and Lebed. To the northeast of the TINRO depression, the Shelikhov Bay trench extends.

The deepest depression is TINRO, located west of Kamchatka. Its bottom is a plain lying at a depth of about 850 m, with a maximum depth of 990 m.

The Deryugin Depression is located east of the underwater base of Sakhalin. Its bottom is a flat plain, raised at the edges, lying on average at a depth of 1700 m, the maximum depth of the depression is 1744 m.

The Kuril Depression is the deepest. This is a huge flat plain lying at a depth of about 3300 m. Its width in the western part is approximately 212 km, and its length in the northeast direction is about 870 km.

Bottom topography and currents of the Sea of ​​Okhotsk

Currents

Under the influence of winds and the influx of water through the Kuril Straits, the characteristic features of the system of non-periodic currents of the Sea of ​​Okhotsk are formed. The main one is a cyclonic system of currents, covering almost the entire sea. It is caused by the predominance of cyclonic atmospheric circulation over the sea and the adjacent part of the Pacific Ocean. In addition, stable anticyclonic gyres can be traced in the sea: to the west of the southern tip of Kamchatka (approximately between 50-52° N and 155-156° E); above the TINRO depression (55-57° N and 150-154° E); in the area of ​​the Southern Basin (45-47° N and 144-148° E). In addition, a vast area of ​​cyclonic water circulation is observed in the central part of the sea (47-53° N and 144-154° E), and the cyclonic circulation is to the east and northeast of the northern tip of the island. Sakhalin (54-56° N and 143-149° E).

Strong currents move around the sea along the coastline counterclockwise: the warm Kamchatka Current, directed north into Shelikhov Bay; flow of a western and then southwestern direction along the northern and northwestern shores of the sea; the stable East Sakhalin Current going south, and the rather strong Soya Current entering the Sea of ​​Okhotsk through the La Perouse Strait.

On the southeastern periphery of the cyclonic circulation of the central part of the sea, a branch of the Northeast Current is distinguished, opposite in direction to the Kuril Current in the Pacific Ocean. As a result of the existence of these flows, stable areas of convergence of currents are formed in some of the Kuril straits, which leads to lowering of waters and has a significant impact on the distribution of oceanological characteristics not only in the straits, but also in the sea itself. And finally, another feature of the circulation of the waters of the Sea of ​​​​Okhotsk is two-way stable currents in most of the Kuril Straits.

Surface currents on the surface of the Sea of ​​Okhotsk are most intense off the western coast of Kamchatka (11-20 cm/s), in the Sakhalin Gulf (30-45 cm/s), in the Kuril Straits (15-40 cm/s), over the Southern Basin ( 11-20 cm/s) and during the Soya (up to 50-90 cm/s). In the central part of the cyclonic region, the intensity of horizontal transport is much less than at its periphery. In the central part of the sea, velocities vary from 2 to 10 cm/s, with the predominant velocities being less than 5 cm/s. A similar picture is observed in Shelikhov Bay: fairly strong currents off the coast (up to 20-30 cm/s) and low speeds in the central part of the cyclonic gyre.

In the Sea of ​​Okhotsk, various types of periodic tidal currents are well expressed: semidiurnal, diurnal and mixed with a predominance of semidiurnal or diurnal components. Tidal current speeds range from a few centimeters to 4 m/s. Far from the coast, current speeds are low - 5-10 cm/s. In straits, bays and off the coast, their speeds increase significantly. For example, in the Kuril Straits, current speeds reach 2-4 m/s.

The tides of the Sea of ​​Okhotsk are very complex. The tidal wave enters from the south and southeast from the Pacific Ocean. The semidiurnal wave moves north, and at the 50° parallel it divides into two parts: the western one turns northwest, and the eastern one moves toward Shelikhov Bay. The daily wave also moves north, but at the latitude of the northern tip of Sakhalin it is divided into two parts: one enters Shelikhov Bay, the other reaches the northwestern coast.

Diurnal tides are the most widespread in the Sea of ​​Okhotsk. They are developed in the Amur Estuary, Sakhalin Bay, on the coast of the Kuril Islands, off the western coast of Kamchatka and in the Gulf of Penzhina. Mixed tides are observed on the northern and northwestern coasts of the sea and in the area of ​​the Shantar Islands.

The highest tides (up to 13 m) were recorded in Penzhinskaya Bay (Cape Astronomichesky). In the area of ​​the Shantar Islands, the tide exceeds 7 m. The tides are significant in the Sakhalin Bay and in the Kuril Straits. In the northern part of the sea their size reaches 5 m.

Fur seal rookery

The lowest tides were observed off the eastern coast of Sakhalin, in the area of ​​the La Perouse Strait. In the southern part of the sea, the tides are 0.8-2.5 m.

In general, tidal level fluctuations in the Sea of ​​Okhotsk are very significant and have a significant impact on its hydrological regime, especially in the coastal zone.

In addition to tidal fluctuations, surge level fluctuations are also well developed here. They occur mainly when deep cyclones pass over the sea. Surge increases in level reach 1.5-2 m. The largest surges are noted on the coast of Kamchatka and in Terpeniya Bay.

The considerable size and great depths of the Sea of ​​Okhotsk, frequent and strong winds above it determine the development of large waves here. The sea is especially rough in the fall, and in ice-free areas even in winter. These seasons account for 55-70% of storm waves, including those with wave heights of 4-6 m, and the highest wave heights reach 10-11 m. The most turbulent are the southern and south-eastern regions of the sea, where the average frequency of storm waves is 35 -40%, and in the northwestern part it decreases to 25-30%. When the waves are strong, a crowd forms in the straits between the Shantar Islands.

Climate

The Sea of ​​Okhotsk is located in the monsoon climate zone of temperate latitudes. A significant part of the sea in the west extends deep into the mainland and lies relatively close to the cold pole of the Asian landmass, so the main source of cold for the Sea of ​​Okhotsk is located to the west of it. The relatively high ridges of Kamchatka make it difficult for warm Pacific air to penetrate. Only in the southeast and south is the sea open to the Pacific Ocean and the Sea of ​​Japan, from where a significant amount of heat enters it. However, the influence of cooling factors is stronger than warming ones, so the Sea of ​​Okhotsk is generally cold. At the same time, due to the large meridional extent, significant differences in synoptic conditions and meteorological conditions arise here. In the cold part of the year (from October to April), the sea is affected by the Siberian Anticyclone and the Aleutian Low. The influence of the latter extends mainly to the southeastern part of the sea. This distribution of large-scale pressure systems causes strong, sustained northwest and northerly winds, often reaching gale force. Little wind and calm are almost completely absent, especially in January and February. In winter, the wind speed is usually 10-11 m/s.

The dry and cold Asian winter monsoon significantly cools the air over the northern and northwestern regions of the sea. In the coldest month - January - the average air temperature in the north-west of the sea is -20 - 25°, in the central regions -10-15°, and in the south-eastern part of the sea it is -5 - 6°.

In autumn-winter, cyclones of predominantly continental origin enter the sea. They bring with them increased wind, sometimes a decrease in air temperature, but the weather remains clear and dry, as continental air arrives from the cooled mainland. In March - April, a restructuring of large-scale pressure fields occurs. The Siberian anticyclone is collapsing, and the Hawaiian high is intensifying. As a result, during the warm season (from May to October), the Sea of ​​Okhotsk is influenced by the Hawaiian High and the low pressure area located over Eastern Siberia. At this time, weak south-easterly winds prevail over the sea. Their speed usually does not exceed 6-7 m/s. These winds are most common in June and July, although stronger northwest and northerly winds are sometimes observed during these months. In general, the Pacific (summer) monsoon is weaker than the Asian (winter) monsoon, since in the warm season the horizontal pressure gradients are smoothed out.

In summer, the average monthly air temperature in August decreases from the southwest (from 18°) to the northeast (to 10-10.5°).

In the warm season, tropical cyclones - typhoons - quite often pass over the southern part of the sea. They are associated with increased winds to storm force, which can last up to 5-8 days. The predominance of south-eastern winds in the spring-summer season leads to significant cloudiness, precipitation, and fog.

Monsoon winds and stronger winter cooling of the western part of the Sea of ​​Okhotsk compared to the eastern are important climatic features of this sea.

Quite a lot of mostly small rivers flow into the Sea of ​​Okhotsk, therefore, despite the significant volume of its waters, the continental flow is relatively small. It is approximately 600 km 3 /year, with about 65% of the flow coming from the Amur. Other relatively large rivers - Penzhina, Okhota, Uda, Bolshaya (in Kamchatka) - bring significantly less fresh water to the sea. Runoff occurs mainly in spring and early summer. At this time, its greatest influence is felt mainly in the coastal zone, near the mouths of large rivers.

Hydrology and water circulation

Geographical location, large length along the meridian, monsoon wind changes and good communication between the sea and the Pacific Ocean through the Kuril Straits are the main natural factors that most significantly influence the formation of the hydrological conditions of the Sea of ​​Okhotsk. The amounts of heat inflow and outflow into the sea are determined mainly by the rational heating and cooling of the sea. The heat brought by Pacific waters is of subordinate importance. However, for the water balance of the sea, the arrival and flow of water through the Kuril Straits plays a decisive role.

The flow of surface Pacific waters into the Sea of ​​Okhotsk occurs mainly through the northern straits, in particular through the First Kuril Strait. In the straits of the middle part of the ridge, both the influx of Pacific waters and the outflow of Okhotsk waters are observed. Thus, in the surface layers of the Third and Fourth Straits, apparently, there is a flow of water from the Sea of ​​Okhotsk, in the bottom layers there is an influx, and in the Bussol Strait it’s the other way around: in the surface layers there is an influx, in the deep layers there is a runoff. In the southern part of the ridge, mainly through the Ekaterina and Frieze straits, water predominantly drains from the Sea of ​​Okhotsk. The intensity of water exchange through the straits can vary significantly.

In the upper layers of the southern part of the Kuril ridge, the flow of Sea of ​​Okhotsk waters predominates, and in the upper layers of the northern part of the ridge, the influx of Pacific waters occurs. In the deep layers, the influx of Pacific waters predominates.

Water temperature and salinity

The influx of Pacific waters significantly affects the distribution of temperature, salinity, structure formation and general circulation of waters in the Sea of ​​Okhotsk. It is characterized by a subarctic water structure, in which cold and warm intermediate layers are well defined in summer. A more detailed study of the subarctic structure in this sea showed that there are Sea of ​​Okhotsk, Pacific and Kuril varieties of the subarctic water structure. Although they have the same vertical structure, they have quantitative differences in the characteristics of water masses.

The following water masses are distinguished in the Sea of ​​Okhotsk:

surface water mass that has spring, summer and autumn modifications. It is a thin heated layer 15-30 m thick, which limits the upper maximum of stability, determined mainly by temperature. This water mass is characterized by temperature and salinity values ​​corresponding to each season;

The Sea of ​​Okhotsk water mass is formed in winter from surface water and in spring, summer and autumn appears in the form of a cold intermediate layer lying between horizons of 40-150 m. This water mass is characterized by a fairly uniform salinity (31-32.9‰) and varying temperatures. In most of the sea its temperature is below 0° and reaches -1.7°, and in the area of ​​the Kuril Straits it is above 1°;

The intermediate water mass is formed mainly due to the descent of water along underwater slopes, within the sea, ranging from 100-150 to 400-700 m, and is characterized by a temperature of 1.5° and a salinity of 33.7‰. This water mass is distributed almost everywhere, except for the northern part of the sea, Shelikhov Bay and some areas along the coast of Sakhalin, where the Sea of ​​Okhotsk water mass reaches the bottom. The thickness of the layer of intermediate water mass decreases from south to north;

The deep Pacific water mass is the water of the lower part of the warm layer of the Pacific Ocean, entering the Sea of ​​Okhotsk at horizons below 800-1000 m, i.e. below the depth of the waters descending in the straits, and in the sea it appears in the form of a warm intermediate layer. This water mass is located at horizons of 600-1350 m, has a temperature of 2.3° and a salinity of 34.3‰. However, its characteristics change in space. The highest values ​​of temperature and salinity are observed in the northeastern and partly in the northwestern regions, which is associated here with rising waters, and the lowest values ​​of the characteristics are characteristic of the western and southern regions, where subsidence of waters occurs.

The water mass of the southern basin is of Pacific origin and represents the deep water of the northwestern part of the Pacific Ocean near the horizon of 2300 m, i.e. horizon corresponding to the maximum depth of the threshold in the Kuril Straits, located in the Bussol Strait. This water mass fills the basin from a horizon of 1350 m to the bottom and is characterized by a temperature of 1.85° and a salinity of 34.7‰, which vary only slightly with depth.

Among the identified water masses, the Sea of ​​Okhotsk and the deep Pacific are the main ones; they differ from each other not only in thermohaline, but also in hydrochemical and biological parameters.

The water temperature at the sea surface decreases from south to north. In winter, almost everywhere the surface layers are cooled to a freezing temperature of –1.5-1.8°. Only in the southeastern part of the sea does it remain around 0°, and near the northern Kuril Straits, under the influence of Pacific waters, the water temperature reaches 1-2°.

Spring warming at the beginning of the season mainly leads to the melting of ice, only towards the end of it does the water temperature begin to rise.

In summer, the distribution of water temperature on the sea surface is quite varied. In August, the waters adjacent to the island are warmest (up to 18-19°). Hokkaido. In the central regions of the sea, the water temperature is 11-12°. The coldest surface waters are observed near the island. Iona, near Cape Pyagin and near the Krusenstern Strait. In these areas, the water temperature is between 6-7°. The formation of local centers of increased and decreased water temperatures on the surface is mainly associated with the redistribution of heat by currents.

The vertical distribution of water temperature varies from season to season and from place to place. In the cold season, temperature changes with depth are less complex and varied than in warm seasons.

In winter, in the northern and central regions of the sea, water cooling extends to horizons of 500-600 m. The water temperature is relatively uniform and varies from -1.5-1.7° on the surface to -0.25° at horizons of 500-600 m, deeper rises to 1-0°, in the southern part of the sea and near the Kuril Straits the water temperature from 2.5-3° on the surface drops to 1-1.4° at horizons of 300-400 m and then gradually rises to 1.9-2 .4° in the bottom layer.

In summer, surface waters are heated to a temperature of 10-12°. In the subsurface layers, the water temperature is slightly lower than on the surface. A sharp drop in temperature to -1 - 1.2° is observed between horizons of 50-75 m, deeper, to horizons of 150-200 m, the temperature quickly rises to 0.5 - 1°, and then it rises more smoothly, and at horizons of 200 - 250 m is equal to 1.5 - 2°. Further, the water temperature remains almost unchanged until the bottom. In the southern and southeastern parts of the sea, along the Kuril Islands, the water temperature from 10 - 14° on the surface drops to 3 - 8° at a horizon of 25 m, then to 1.6-2.4° at a horizon of 100 m and to 1 ,4-2° at the bottom. The vertical temperature distribution in summer is characterized by a cold intermediate layer. In the northern and central regions of the sea the temperature is negative, and only near the Kuril Straits it has positive values. In different areas of the sea, the depth of the cold intermediate layer is different and varies from year to year.

The distribution of salinity in the Sea of ​​Okhotsk varies relatively little between seasons. Salinity increases in the eastern part, which is under the influence of Pacific waters, and decreases in the western part, desalinated by continental runoff. In the western part, salinity on the surface is 28-31‰, and in the eastern part - 31-32‰ and more (up to 33‰ near the Kuril ridge),

In the northwestern part of the sea, due to desalination, the salinity on the surface is 25‰ or less, and the thickness of the desalinated layer is about 30-40 m.

Salinity increases with depth in the Sea of ​​Okhotsk. At horizons of 300-400 m in the western part of the sea, salinity is 33.5‰, and in the eastern part it is about 33.8‰. At a horizon of 100 m, salinity is 34‰ and then towards the bottom it increases slightly, by only 0.5-0.6‰.

In individual bays and straits, the salinity value and its stratification may differ significantly from the waters of the open sea, depending on local conditions.

In accordance with temperature and salinity, denser waters are observed in winter in the northern and central areas of the sea, covered with ice. The density is somewhat lower in the relatively warm Kuril region. In summer, the density of water decreases, its lowest values ​​are confined to zones of influence of coastal runoff, and the highest are observed in areas of distribution of Pacific waters. In winter, it rises slightly from the surface to the bottom. In summer, its distribution depends on temperature in the upper layers, and on salinity in the middle and lower layers. In summer, a noticeable density stratification of waters is created vertically, the density increases especially noticeably at horizons of 25-50 m, which is associated with the heating of waters in open areas and desalination off the coast.

Wind mixing occurs during the ice-free season. It occurs most intensely in spring and autumn, when strong winds blow over the sea, and the stratification of waters is not yet very pronounced. At this time, wind mixing extends to horizons of 20-25 m from the surface.

Intense ice formation over most of the sea stimulates enhanced thermohaline winter vertical circulation. At depths of up to 250-300 m, it spreads to the bottom, and below it is prevented by the maximum stability that exists here. In areas with rugged bottom topography, the spread of density mixing into the lower horizons is facilitated by the sliding of water along the slopes.

Ice cover

Severe and long winters with strong northwest winds contribute to the development of large masses of ice in the sea. The ice of the Sea of ​​Okhotsk is an exclusively local formation. Here there are both fixed ice - fast ice, and floating ice, which is the main form of sea ice.

Ice is found in varying amounts in all areas of the sea, but in summer the entire sea is cleared of ice. The exception is the area of ​​the Shantar Islands, where ice can persist in the summer.

Ice formation begins in November in the bays and lips of the northern part of the sea, in the coastal part of the island. Sakhalin and Kamchatka. Then ice appears in the open part of the sea. In January and February, ice covers the entire northern and middle part of the sea.

In normal years, the southern border of the relatively stable ice cover bends to the north and runs from the La Perouse Strait to Cape Lopatka.

The extreme southern part of the sea never freezes. However, thanks to the winds, significant masses of ice are carried into it from the north, often accumulating near the Kuril Islands.

From April to June, destruction and gradual disappearance of the ice cover occurs. On average, sea ice disappears in late May - early June. The northwestern part of the sea, due to currents and the configuration of the shores, is most clogged with ice, which persists until July. Ice cover in the Sea of ​​Okhotsk lasts for 6-7 months. More than 3/4 of the sea surface is covered with floating ice. The compact ice of the northern part of the sea poses serious obstacles to navigation even for icebreakers.

The total duration of the ice period in the northern part of the sea reaches 280 days a year.

The southern coast of Kamchatka and the Kuril Islands belong to areas with little ice cover: here the ice lasts on average no more than three months a year. The thickness of the ice that grows during the winter reaches 0.8-1 m.

Strong storms and tidal currents break up the ice cover in many areas of the sea, forming hummocks and large open waters. In the open part of the sea, continuous, motionless ice is never observed; usually the ice here is drifting, in the form of vast fields with numerous leads.

Some of the ice from the Sea of ​​Okhotsk is carried into the ocean, where it almost immediately collapses and melts. In severe winters, floating ice is pressed against the Kuril Islands by northwestern winds and clogs some straits.

Economic importance

There are about 300 species of fish in the Sea of ​​Okhotsk. Of these, about 40 species are commercial. The main commercial fish are pollock, herring, cod, navaga, flounder, sea bass, and capelin. Salmon catches (chum salmon, pink salmon, sockeye salmon, coho salmon, chinook salmon) are small.

The area of ​​the Sea of ​​Okhotsk is 1.603 million square meters. km. The average depth is 1780 m and the maximum depth is 3521 m. The western part of the sea has shallow depth and is located on the continental shelf. In the center of the sea are the Deryugin depression (in the south) and the TINRO depression. In the eastern part there is the Kuril Basin, where the depth is maximum.

From October to May-June, the northern part of the sea is covered with ice. The southeastern part practically does not freeze.

The coast in the north is heavily indented; in the northeast of the Sea of ​​Okhotsk its largest bay is located - Shelikhov Bay. Of the smaller bays in the northern part, the most famous are the Eirine Bay and the bays of Sheltinga, Zabiyaka, Babushkina, Kekurny, Odessa Bay on the island of Iturup. In the east, the coastline of the Kamchatka Peninsula is practically devoid of bays. In the southwest, the largest are Aniva and Terpeniya bays.

Fishing (salmon, herring, pollock, capelin, navaga, etc.).

Main ports: on the mainland - Magadan, Ayan, Okhotsk (port point); on the island of Sakhalin - Korsakov, on the Kuril Islands - Severo-Kurilsk.

The Sea of ​​Okhotsk is named after the Okhot River, which in turn comes from the Even word okat - “river”. The Japanese traditionally called this sea "Hokkai" (北海), literally "North Sea". But since now this name refers to the North Sea of ​​the Atlantic Ocean, they changed the name of the Sea of ​​Okhotsk to “Ohotsuku-kai” (オホーツク海), which is an adaptation of the Russian name to the norms of Japanese phonetics.

The sea is located on the Okhotsk subplate, which is part of the Eurasian plate. The crust under most of the Sea of ​​Okhotsk is of continental type.

THE SEA OF OKHOTSK is a marginal sea in the northwestern part of the Pacific Ocean.

The Sea of ​​Okhotsk is almost completely limited by continental and island coastlines, located between the shores of Eastern Eurasia, its Kamchatka Peninsula, the Kuril Islands chain, the northern tip of Hokkaido and the eastern part of Sakhalin Island. It is separated from the Sea of ​​Japan in the Tatar Strait along the line Cape Sushchev - Cape Tyk, in the La Perouse Strait along the line Cape Crillon - Cape Soya. The border with the Pacific Ocean runs from Cape Nosyappu (Hokkaido Island) along the ridge of the Kuril Islands to Cape Lopatka (Kamchatka Peninsula). Area 1603 thousand km2, volume 1316 thousand km3, greatest depth 3521 m.

The coastline is slightly indented, the largest bays are: Academies, Aniva, Sakhalinsky, Terpeniya, Tugursky, Ulbansky, Shelikhova (with Gizhiginskaya and Penzhinskaya bays); Tauiskaya, Udskaya lips. The north and northwestern shores are predominantly elevated and rocky, most of them abrasive, in places heavily altered by the sea; in Kamchatka, in the northern parts of Sakhalin and Hokkaido, as well as at the mouths of large rivers - low-lying, largely accumulative. Most of the islands are located near the coast: Zavyalova, Spafareva, Shantarskie, Yamskie, and only the small island of Jonah is located in the open sea.

Relief and geological structure of the bottom.

The bottom topography is very diverse. The shelf occupies about 40% of the bottom area, it is most common in the northern part, where it is of the submerged type, its width varies from 180 km near the Ayano-Okhotsk coast to 370 km in the Magadan region. Up to 50% of the bottom area falls on the continental slope (depths up to 2000 m). To the south part is the deepest (more than 2500 m) area of ​​the sea, occupying St. 8% pl. bottom. In the central part of the Sea of ​​Okhotsk, the rises of the Academy of Sciences and the Institute of Oceanology are distinguished, dividing the sea depression into 3 basins (depressions): TINRO in the northeast (depth up to 990 m), Deryugin in the west (up to 1771 m) and the deepest - Kuril in the south (up to 3521 m).

The foundation of the Sea of ​​Okhotsk basin is heterogeneous; The thickness of the earth's crust is 10-40 km. The uplift in the central part of the sea has continental crust; the rise in the southern part of the sea consists of two raised blocks separated by a trough. The deep-sea Kuril Basin with oceanic crust, according to some researchers, is a captured section of the ocean plate; according to others, it is a back-arc basin. The Deryugin and TINRO basins are underlain by transitional crust. In the Deryugin basin, an increased heat flow and hydrothermal activity have been established compared to the rest of the territory, as a result of which barite structures are formed. The sedimentary cover is thickest in basins (8-12 km) and on the northern and eastern shelves, composed of Cenozoic terrigenous and siliceous-terrigenous deposits (near the Kuril Islands with an admixture of tuffaceous material). The Kuril Islands chain is characterized by intense seismicity and modern volcanism. Earthquakes that regularly occur in the area often produce dangerous tsunami waves, such as the one in 1958.

Climate.

The Sea of ​​Okhotsk is characterized by a monsoon climate of temperate latitudes. The sea is located relatively close to the Siberian Pole of Cold, and the Kamchatka ridges block the path to warm Pacific air masses, so in general it is cold in this area. From October to April, the combined influence of the Asian anticyclone and the Aleutian depression prevails over the sea with strong, stable northwestern and northern winds with speeds of 10-11 m/s, often reaching storm force. The coldest month is January, temperatures range from -5 to -25 °C. From May to September, the sea is under the influence of the Hawaiian anticyclone with weak southeast winds of 6-7 m/s. In general, the Pacific (summer) monsoon is weaker than the Asian (winter) monsoon. Summer temperatures (August) range from 18 °C in the southwest to 10 °C in the northeast. The average annual precipitation ranges from 300-500 mm in the north, to 600-800 mm in the west, in the southern and south-eastern parts of the sea - over 1000 mm.

Hydrological regime.

Large rivers flow into the Sea of ​​Okhotsk: Amur, Bolshaya, Gizhiga, Okhota, Penzhina, Uda. The river flow is about 600 km3/year, about 65% falls on the Amur. Desalination of the surface layer of the sea is noted. water due to the excess of river flow over evaporation. The geographical location of the Sea of ​​Okhotsk, in particular its large length along the meridian, the monsoon wind regime, and water exchange through the straits of the Kuril ridge with the Pacific Ocean determine the characteristics of the hydrological regime. The total width of all the Kuril Straits reaches 500 km, but the depths above the rapids in the straits vary greatly. For water exchange with the Pacific Ocean, the Bussol straits with a depth of over 2300 m and the Kruzenshtern strait - up to 1920 m are of greatest importance. This is followed by the Frieza, Fourth Kurilsky, Ricord and Nadezhda straits, all with depths at the rapids of more than 500 m. The remaining straits have depths of less than 200 m and small cross-sectional areas. In small straits, unidirectional flows into the sea or into the ocean are usually observed. In deep straits, a two-layer circulation predominates: in the near-surface layer in one direction, in the near-bottom layer in the opposite direction. In the Bussol Strait, Pacific waters flow into the sea in the surface layers, and flow into the ocean in the bottom layers. In general, the flow of Sea of ​​Okhotsk waters predominates in the southern straits, while the influx of Pacific waters predominates in the northern straits. The intensity of water exchange through the straits is affected. seasonal and annual variability.

In the Sea of ​​Okhotsk, a subarctic structure of waters with well-defined cold and warm intermediate layers is observed; the Sea of ​​Okhotsk, Pacific and Kuril regional varieties are distinguished. There are 5 large water masses in the Sea of ​​Okhotsk: the surface one is a very thin (15-30 m) upper layer, which easily mixes and, depending on the season, takes on spring, summer or autumn modifications with corresponding characteristic values ​​of temperature and salinity; in winter, as a result of strong cooling of the surface layer, the Sea of ​​Okhotsk water mass is formed, which in spring, summer and autumn exists in the form of a cold transition layer at horizons from 40 to 150 m, the temperature in this layer is from -1.7 to 1 °C, salinity 31 -32.9‰; the intermediate one is formed as a result of the sliding of cold waters along the continental slope, is characterized by a temperature of 1.5 °C, a salinity of 33.7‰ and occupies a layer from 150 to 600 m; the deep Pacific is located in a layer from 600 to 1300 m, consists of Pacific water entering the Sea of ​​Okhotsk in the lower horizons of the deep Kuril Straits, and exists as a warm intermediate layer with a temperature of about 2.3 °C and a salinity of 34.3‰, deep Kuril the southern basin is also formed from Pacific waters, located in a layer from 1300 m to the bottom, water temperature 1.85 °C, salinity 34.7‰.

The distribution of water temperature on the surface of the Sea of ​​Okhotsk strongly depends on the season. In winter, the water cools to about -1.7 °C. In summer, the waters are heated most strongly near the island. Hokkaido up to 19 °C, in the central regions up to 10-11 °C. Salinity on the surface in the eastern part of the Kuril ridge is up to 33‰, in the western regions 28-31‰.

The circulation of surface waters is predominantly cyclonic in nature (counterclockwise), which is explained by the influence of wind conditions over the sea. Average current speeds are 10-20 cm/s, maximum values ​​can be observed in the straits (up to 90 cm/s in the La Perouse Strait). Periodic tidal currents are well expressed, the tides are mainly daily and mixed, ranging in size from 1.0-2.5 m in the southern part of the sea, up to 7 m near the Shantar Islands and 13.2 m in Penzhinskaya Bay (the largest in the seas of Russia). Significant level fluctuations (surges) of up to 2 m are caused on the coasts during the passage of cyclones.

The Sea of ​​Okhotsk is an arctic sea; ice formation begins in November in the bays of the northern part and by February spreads to most of the surface. Only the extreme southern part does not freeze. In April, the melting and destruction of the ice cover begins; in June, the ice completely disappears. Only in the area of ​​the Shantar Islands can sea ice partially remain until autumn.

History of the study.

The sea was discovered in the middle of the 17th century by Russian explorers I.Yu. Moskvitin and V.D. Poyarkov. The first coastal maps were compiled during the Second Kamchatka Expedition (1733-1743) (see Kamchatka Expeditions). I.F. Kruzenshtern (1805) conducted an inventory of the eastern coast of Sakhalin. G.I. Nevelskoy (1850-1855) examined the southwestern shores of the Sea of ​​Okhotsk and the mouth of the Amur River and proved the island position of Sakhalin. The first complete report on sea hydrology was compiled by S.O. Makarov (1894). In Soviet times, comprehensive research work was launched in the Sea of ​​Okhotsk. Systematic research has been carried out for many years by the Pacific Fisheries Research Center (TINRO-Center), the Pacific Oceanological Institute of the Far Eastern Branch of the Russian Academy of Sciences, several large expeditions were carried out by the Oceanology Institute on the ship "Vityaz", as well as by ships of the Hydrometeorological Service (see Federal Service of Russia for Hydrometeorology and Monitoring Environment), Oceanographic Institute and other institutions.

Economic use.

In the Sea of ​​Okhotsk there are about 300 species of fish, of which about 40 are commercial species, including cod, pollock, herring, navaga, and sea bass. Salmon species are widespread: pink salmon, chum salmon, sockeye salmon, coho salmon, and chinook salmon. Inhabited by whales, seals, sea lions, and fur seals. Crabs are of great economic importance (1st place in the world in terms of commercial crab reserves). The Sea of ​​Okhotsk is promising in terms of hydrocarbons; proven oil reserves exceed 300 million tons. The largest deposits have been identified on the shelves of the Sakhalin, Magadan and West Kamchatka islands (see the article Okhotsk oil and gas province). Sea routes pass through the Sea of ​​Okhotsk connecting Vladivostok with the northern regions of the Far East and the Kuril Islands. Large ports: Magadan, Okhotsk, Korsakov, Severo-Kurilsk.

The Sea of ​​Okhotsk is a sea of ​​the Pacific Ocean, separated from it by the Kamchatka Peninsula, the Kuril Islands and the island of Hokkaido.
The sea washes the shores of Russia and Japan.
Area - 1603 thousand km². The average depth is 1780 m, the maximum depth is 3916 m. The western part of the sea is located above the gentle continuation of the continent and has a shallow depth. In the center of the sea are the Deryugin depression (in the south) and the TINRO depression. In the eastern part there is the Kuril Basin, where the depth is maximum.

Sea of ​​Okhotsk map of the Far East

In the chain of our Far Eastern seas, it occupies a middle position, protrudes quite deeply into the Asian continent, and is separated from the Pacific Ocean by the arc of the Kuril Islands. The Sea of ​​Okhotsk has natural boundaries almost everywhere and only in the southwest from the Sea of ​​Japan it is separated by conventional lines: Cape Yuzhny - Cape Tyk and in the La Perouse Strait Cape Crillon - Cape Soya. The southeastern border of the sea runs from Cape Nosyappu (Hokkaido Island) through the Kuril Islands to Cape Lopatka (Kamchatka), while all passages between the island. Hokkaido and Kamchatka are included in the Sea of ​​Okhotsk. Within these limits, the sea extends from north to south from 62°42′ to 43°43′ N. w. and from west to east from 134°50′ to 164°45′ E. d. The sea is significantly elongated from southwest to northeast and expanded approximately in its central part.

GENERAL DATA, GEOGRAPHY, ISLANDS
The Sea of ​​Okhotsk is one of the largest and deepest seas in our country. Its area is 1603 thousand km2, volume 1318 thousand km3, average depth 821 m, greatest depth 3916 m. According to its geographical location, the predominance of depths up to 500 m and significant spaces occupied by great depths, the Sea of ​​Okhotsk belongs to the marginal seas of mixed continental- marginal type.

There are few islands in the Sea of ​​Okhotsk. The largest border island is Sakhalin. The Kuril ridge has about 30 large and many small islands and rocks. The Kuril Islands are located in a belt of seismic activity, which includes more than 30 active and 70 extinct volcanoes. Seismic activity occurs on the islands and underwater. In the latter case, tsunami waves are formed. In addition to the named “marginal” islands in the sea there are the islands of Shantarskie, Spafareva, Zavyalova, Yamskie and the small island of Jonah - the only one of them remote from the coast.
Although the coastline is long, it is relatively weakly indented. At the same time, it forms several large bays (Aniva, Terpeniya, Sakhalinsky, Akademii, Tugursky, Ayan, Shelikhova) and bays (Udskaya, Tauyskaya, Gizhiginskaya and Penzhinskaya).

Atsonopuri volcano, Iturup island, Kuril Islands

From October to May - June, the northern part of the sea is covered with ice. The southeastern part practically does not freeze.

The coast in the north is strongly indented; in the northeast of the Sea of ​​Okhotsk its largest bay is located - Shelikhov Bay. Of the smaller bays in the northern part, the most famous are the Eirine Bay and the bays of Sheltinga, Zabiyaka, Babushkina, and Kekurny.

In the east, the coastline of the Kamchatka Peninsula is practically devoid of bays. In the west, the coastline is heavily indented, forming the Sakhalin Bay and the Shantar Sea. In the south, the largest are Aniva and Terpeniya bays, Odessa Bay on the island of Iturup.

Fishing (salmon, herring, pollock, capelin, navaga, etc.), seafood (Kamchatka crab).

Hydrocarbon production on the Sakhalin shelf.

The Amur, Okhota, and Kukhtui rivers flow into it.

Sea of ​​Okhotsk Cape Velikan, Sakhalin Island

Main ports:
on the mainland - Magadan, Ayan, Okhotsk (port point); on the island of Sakhalin - Korsakov, on the Kuril Islands - Severo-Kurilsk.
The sea is located on the Okhotsk subplate, which is part of the Eurasian plate. The crust under most of the Sea of ​​Okhotsk is of continental type.

The Sea of ​​Okhotsk is named after the Okhota River, which in turn comes from Evensk. okat - “river”. Previously it was called Lamsky (from Evensk. Lam - “sea”), as well as the Kamchatka Sea. The Japanese traditionally called this sea Hokkai (北海), literally "North Sea". But since now this name refers to the North Sea of ​​the Atlantic Ocean, they changed the name of the Sea of ​​Okhotsk to Ohotsuku-kai (オホーツク海), which is an adaptation of the Russian name to the norms of Japanese phonetics.

Cape Medyay Sea of ​​Okhotsk

Territorial regime
The Sea of ​​Okhotsk consists of internal waters, the territorial sea and the exclusive economic zone of two coastal states - Russia and Japan. In terms of its international legal status, the Sea of ​​Okhotsk is closest to a semi-enclosed sea (Article 122 of the UN Convention on the Law of the Sea), since it is surrounded by two or more states and mainly consists of the territorial sea and the exclusive economic zone of two states, but it is not such, since connected to the rest of the world's oceans not by a single narrow passage, but by a series of passages.
In the central part of the sea, at a distance of 200 nautical miles from the baselines, there is a section elongated in the meridional direction, traditionally called Peanut Hole in English literature, which is not included in the exclusive economic zone and is the open sea outside the jurisdiction of Russia; in particular, any country in the world has the right here to fish and conduct other activities permitted by the UN Convention on the Law of the Sea, excluding activities on the shelf. Since this region is an important element for the reproduction of the population of some species of commercial fish, the governments of some countries directly prohibit their vessels from fishing in this area of ​​​​the sea.

On November 13-14, 2013, the Subcommission created within the UN Commission on the Limits of the Continental Shelf agreed with the arguments of the Russian delegation as part of the consideration of the Russian Federation’s application to recognize the bottom of the above-mentioned area of ​​the high seas as a continuation of the Russian continental shelf. On March 15, 2014, the 33rd session of the Commission in 2014 adopted a positive decision on the Russian application, first submitted in 2001, and submitted in a new version at the beginning of 2013, and the central part of the Sea of ​​Okhotsk outside the exclusive economic zone of the Russian Federation was recognized continental shelf of Russia.
Consequently, in the central part, other states are prohibited from extracting “sessile” biological resources (for example, crab) and from subsoil development. The fishing of other biological resources, such as fish, is not subject to restrictions on the continental shelf. Consideration of the application on its merits became possible thanks to the position of Japan, which, with an official note dated May 23, 2013, confirmed its consent to the Commission’s consideration of the essence of the application, regardless of the resolution of the issue of the Kuril Islands. Sea of ​​Okhotsk

Temperature and salinity
In winter, the water temperature at the sea surface ranges from −1.8 to 2.0 °C; in summer, the temperature rises to 10-18 °C.
Below the surface layer, at depths of about 50-150 meters, there is an intermediate cold layer of water, the temperature of which does not change throughout the year and is about −1.7 °C.
The waters of the Pacific Ocean entering the sea through the Kuril Straits form deep water masses with a temperature of 2.5 - 2.7 °C (at the very bottom - 1.5-1.8 °C). In coastal areas with significant river flow, the water temperature in winter is about 0 °C, in summer - 8-15 °C.
The salinity of surface sea waters is 32.8–33.8 ppm. The salinity of the intermediate layer is 34.5‰. Deep waters have a salinity of 34.3 - 34.4 ‰. Coastal waters have a salinity of less than 30 ‰.

RESCUE OPERATION
Incident in December 2010 - January 2011
Icebreaker "Krasin" (built in 1976), an analogue of the icebreaker "Admiral Makarov" (built in 1975)

From December 30, 2010 to January 31, 2011, a rescue operation was carried out in the Sea of ​​Okhotsk, which received widespread media coverage.
The operation itself was large-scale; according to Deputy Minister of Transport Viktor Olersky and head of Rosrybolovstvo Andrei Krainiy, rescue operations on such a scale have not been carried out in Russia for 40 years.
The cost of the operation was between 150 and 250 million rubles, and 6,600 tons of diesel fuel were consumed.
15 ships carrying about 700 people were captured in the ice.
The operation was carried out by an icebreaker flotilla: the icebreakers Admiral Makarov and Krasin, the icebreaker Magadan and the tanker Victoria served as auxiliary vessels. The coordination headquarters of the rescue operation was located in Yuzhno-Sakhalinsk, the work was carried out under the leadership of the Deputy Minister of Transport of the Russian Federation Viktor Olersky.

Most of the ships got out on their own, icebreakers rescued four ships: the trawler "Cape Elizabeth", the research vessel "Professor Kiesewetter" (first half of January, "Admiral Makarov"), the refrigerator "Coast of Hope" and the floating base "Commonwealth".
The first help was provided to the seiner "Cape Elizabeth", whose captain sailed his ship after the ban on entry into the area was imposed.
As a result, “Cape Elizabeth” was frozen into ice in the Sakhalin Bay area. Sea of ​​Okhotsk

The second ship to be released was the Professor Kiesewetter, whose captain, as a result of the investigation, was deprived of his diploma for six months.
In the area of ​​January 14, icebreakers brought together the remaining vessels in distress, after which the icebreakers escorted both vessels of the caravan in a coupled manner.
After the “Whiskers” of the “Commonwealth” broke, it was decided to first move the refrigerator through the heavy ice.
The wiring was suspended in the area on January 20 due to weather conditions, but on January 24 it was possible to bring the Bereg Nadezhdy refrigerator into clean water.
On January 25, after bunkering, the Admiral Makarov returned to escort the mother ship.
On January 26, the towing “whiskers” broke again, and we had to lose time to deliver new ones by helicopter.
On January 31, the floating base "Commonwealth" was also removed from ice captivity; the operation ended at 11:00 Vladivostok time.

HOKKAIDO ISLAND
Hokkaido (Japanese: “Government of the North Sea”), formerly known as Ezo, in the old Russian transcription Iesso, Ieddo, Iedzo, is the second largest island of Japan. Until 1859, it was also called Matsumae after the surname of the ruling feudal clan, which owned the castle town of Matsumae - in the old Russian transcription - Matsmai, Matsmai.
It is separated from the island of Honshu by the Sangar Strait, but the Seikan Tunnel is built between these islands under the seabed. The largest city of Hokkaido and the administrative center of the prefecture of the same name is Sapporo. The northern coast of the island is washed by the cold Sea of ​​Okhotsk and faces the Pacific coast of the Russian Far East. The territory of Hokkaido is almost equally divided between mountains and plains. Moreover, the mountains are located in the center of the island and stretch in ridges from north to south. The highest peak is Mount Asahi (2290 m). In the western part of the island, along the Ishikari River (length 265 km), there is a valley of the same name, in the eastern part, along the Tokachi River (156 km) there is another valley. The southern part of Hokkaido forms the Oshima Peninsula, separated by the Sangar Strait from Honshu.
The easternmost point of Japan is located on the island - Cape Nosappu-Saki. The northernmost point of Japan is also located on it - Cape Soya.

Cape Krasny, Three Brothers Islands

SHELEKHOV BAY
Shelikhov Bay is a bay of the Sea of ​​Okhotsk between the coast of Asia and the base of the Kamchatka Peninsula. The bay received its name in honor of G.I. Shelikhov.
Length - 650 km, width at the entrance - 130 km, maximum width - 300 km, depth up to 350 m.
In the northern part of the peninsula, Taigonos is divided into Gizhiginskaya Bay and Penzhinskaya Bay. The rivers Gizhiga, Penzhina, Yama, and Malkachan flow into the bay.
Covered with ice from December to May. Tides are irregular, semidiurnal. In Penzhinskaya Bay they reach their maximum values ​​for the Pacific Ocean.
The bay is rich in fish resources. Fishing objects include herring, halibut, flounder, and Far Eastern navaga.
In the southern part of Shelikhov Bay there is a small archipelago of the Yamsky Islands.
In Shelikhov Bay, tides reach 14 m.

Sakhalin Bay, swans have arrived Sea of ​​Okhotsk

SAKHALIN GULF
Sakhalin Bay is a bay of the Sea of ​​Okhotsk between the coast of Asia north of the mouth of the Amur and the northern tip of Sakhalin Island.
In the northern part it is wide, to the south it narrows and passes into the Amur Estuary. Width up to 160 km, the Nevelskoy Strait is connected to the Tatar Strait and the Sea of ​​Japan.
From November to June it is covered with ice.
Tides are irregular daily, up to 2-3 m.
Industrial fishing (salmon, cod) is carried out in the waters of the bay.
The port of Moskalvo is located on the shore of the bay.

Aniva Bay, Korsakov port, Sakhalin Island

ANIVA BAY
Aniva is a bay of the Sea of ​​Okhotsk, off the southern coast of Sakhalin Island, between the Krillonsky and Tonino-Aniva peninsulas. From the south it is wide open into the La Perouse Strait.
The origin of the bay's name is most likely related to the Ainu words "an" and "iva". The first is usually translated as “available, located”, and the second as “mountain ridge, rock, peak”; thus, "Aniva" can be translated as "having ridges" or "located among ridges (mountains)."
Width 104 km, length 90 km, greatest depth 93 meters. The narrowed part of the bay is known as Salmon Bay. The warm Soya current influences the temperature regime and the dynamics of currents inside the bay, which are variable.

Sakhalin (Japanese: 樺太，Chinese: 库页/庫頁) is an island off the eastern coast of Asia. It is part of the Sakhalin region. The largest island in Russia. It is washed by the Seas of Okhotsk and Japan. It is separated from mainland Asia by the Tatar Strait (at its narrowest part, the Nevelskoy Strait, it is 7.3 km wide and freezes in winter); from the Japanese island of Hokkaido - the La Perouse Strait.

The island got its name from the Manchu name of the Amur River - “Sakhalyan-ulla”, which translated means “Black River” - this name, printed on the map, was mistakenly attributed to Sakhalin, and in subsequent editions of maps it was printed as the name of the island.

The Japanese call Sakhalin Karafuto, this name goes back to the Ainu “kamuy-kara-puto-ya-mosir”, which means “land of the god of the mouth”. In 1805, a Russian ship under the command of I. F. Krusenstern explored most of the coast of Sakhalin and concluded that Sakhalin was a peninsula. In 1808, Japanese expeditions led by Matsuda Denjuro and Mamiya Rinzou proved that Sakhalin is an island. Most European cartographers were skeptical of the Japanese data. For a long time, on various maps Sakhalin was designated either an island or a peninsula. Only in 1849 did an expedition under the command of G.I. Nevelsky put a final point on this issue, passing on the military transport ship “Baikal” between Sakhalin and the mainland. This strait was subsequently named after Nevelsky.

The island extends meridionally from Cape Crillon in the south to Cape Elizabeth in the north. Length 948 km, width from 26 km (Poyasok isthmus) to 160 km (at the latitude of the village of Lesogorskoye), area 76.4 thousand km².

BAY OF PATIENCE
Terpeniya Bay is a bay of the Sea of ​​Okhotsk off the southeastern coast of Sakhalin Island. In the eastern part it is partially limited by the Terpeniya Peninsula.
The bay was discovered in 1643 by the Dutch navigator M. G. De Vries and was named Terpeniya Bay by him, since his expedition had to wait out thick fog here for a long time, which made it impossible to continue sailing.
The length of the bay is 65 km, width is about 130 km, depth is up to 50 m. The Poronai River flows into the bay.
In winter the bay freezes.
The waters of the bay are rich in biological resources, including chum salmon and pink salmon.
The port of Poronaysk is located in Terpeniya Bay. Sea of ​​Okhotsk

- a chain of islands between the Kamchatka Peninsula and the island of Hokkaido, separating the Sea of ​​Okhotsk from the Pacific Ocean with a slightly convex arc.
Length - about 1200 km. The total area is 10.5 thousand km². To the south of them lies the state border of the Russian Federation with Japan.
The islands form two parallel ridges: the Greater Kuril and the Lesser Kuril. Includes 56 islands. They have important military-strategic and economic significance. The Kuril Islands are part of the Sakhalin region of Russia. The southern islands of the archipelago - Iturup, Kunashir, Shikotan and the Habomai group - are disputed by Japan, which includes them in Hokkaido Prefecture.

Belongs to the regions of the Far North
The climate on the islands is maritime, quite harsh, with cold and long winters, cool summers, and high humidity. The mainland monsoon climate undergoes significant changes here. In the southern part of the Kuril Islands, frosts in winter can reach −25 °C, the average temperature in February is −8 °C. In the northern part, winter is milder, with frosts down to −16 °C and −7 °C in February.
In winter, the islands are affected by the Aleutian baric minimum, the effect of which weakens by June.
The average August temperature in the southern part of the Kuril Islands is +17 °C, in the northern part - +10 °C.

List of islands with an area greater than 1 km² in a north-south direction.
Name, Area, km², height, Latitude, Longitude
Great Kuril Ridge
Northern group
Atlasova 150 2339 50°52" 155°34"
Shumshu 388 189 50°45" 156°21"
Paramushir 2053 1816 50°23" 155°41"
Antsiferova 7 747 50°12" 154°59"
Makanrushi 49 1169 49°46" 154°26"
Onekotan 425 1324 49°27" 154°46"
Kharimkotan 68 1157 49°07" 154°32"
Chirinkotan 6 724 48°59" 153°29"
Ekarma 30 1170 48°57" 153°57"
Shiashkotan 122 934 48°49" 154°06"

Middle group
Raikoke 4.6 551 48°17" 153°15"
Matua 52 1446 48°05" 153°13"
Rashua 67 948 47°45" 153°01"
Ushishir Islands 5 388 — —
Ryponkich 1.3 121 47°32" 152°50"
Yankich 3.7 388 47°31" 152°49"
Ketoy 73 1166 47°20" 152°31"
Simushir 353 1539 46°58" 152°00"
Broughton 7 800 46°43" 150°44"
Black Brothers Islands 37,749 — —
Chirpoy 21 691 46°30" 150°55"
Brat-Chirpoev 16 749 46°28" 150°50"

Southern group
Urup 1450 1426 45°54" 149°59"
Iturup 3318.8 1634 45°00" 147°53"
Kunashir 1495.24 1819 44°05" 145°59"

Small Kuril ridge
Shikotan 264.13 412 43°48" 146°45"
Polonsky 11.57 16 43°38" 146°19"
Green 58.72 24 43°30" 146°08"
Tanfilyeva 12.92 15 43°26" 145°55"
Yuri 10.32 44 43°25" 146°04"
Anuchina 2.35 33 43°22" 146°00"

Geological structure
The Kuril Islands are a typical ensimatic island arc on the edge of the Okhotsk plate. It lies above a subduction zone in which the Pacific plate is being absorbed. Most of the islands are mountainous. The highest altitude is 2339 m - Atlasov Island, Alaid Volcano. The Kuril Islands are located in the Pacific volcanic ring of fire in a zone of high seismic activity: out of 68 volcanoes, 36 are active, and there are hot mineral springs. Large tsunamis are common. The best known are the tsunami of November 5, 1952 at Paramushir and the Shikotan tsunami of October 5, 1994. The last major tsunami occurred on November 15, 2006 in Simushir.

DETAILED GEOGRAPHY OF THE SEA OF OKHOTSK, DESCRIPTION OF THE SEA
Main physical and geographical features.
The straits connecting the Sea of ​​Okhotsk with the Pacific Ocean and the Sea of ​​Japan, and their depths, are very important, as they determine the possibility of water exchange. The Nevelskoy and La Perouse straits are relatively narrow and shallow. The width of the Nevelskoy Strait (between capes Lazarev and Pogibi) is only about 7 km. The width of the La Perouse Strait is slightly larger - about 40 km, and the greatest depth is 53 m.

At the same time, the total width of the Kuril Straits is about 500 km, and the maximum depth of the deepest of them (Bussol Strait) exceeds 2300 m. Thus, the possibility of water exchange between the Sea of ​​Japan and the Sea of ​​Okhotsk is incomparably less than between the Sea of ​​Okhotsk and the Pacific Ocean. However, even the depth of the deepest of the Kuril Straits is significantly less than the maximum depth of the sea, therefore g, fencing off the sea depression from the ocean.
The most important for water exchange with the ocean are the Bussol and Krusenstern straits, since they have the largest area and depth. The depth of the Bussol Strait was indicated above, and the depth of the Kruzenshtern Strait is 1920 m. Of less importance are the Frieza, Fourth Kurilsky, Rikord and Nadezhda straits, whose depths are more than 500 m. The depths of the remaining straits generally do not exceed 200 m, and the areas are insignificant.

The shores of the Sea of ​​Okhotsk, which are different in external shape and structure in different areas, belong to different geomorphological types. From Fig. 38 it is clear that for the most part these are abrasive shores modified by the sea; only in the west of Kamchatka and in the east of Sakhalin are there accumulative shores. The sea is mostly surrounded by high and steep shores. In the north and northwest, rocky ledges descend directly to the sea. A less high, and then low, continental coast approaches the sea near Sakhalin Bay. The southeastern coast of Sakhalin is low, and the northeastern coast is low. very steep. The northeastern coast of Hokkaido is predominantly low-lying. The coast of the southern part of western Kamchatka has the same character, but its northern part is distinguished by some elevation of the coast.

The bottom topography of the Sea of ​​Okhotsk is varied and uneven. In general, it is characterized by the following main features. The northern part of the sea is a continental shelf - an underwater continuation of the Asian continent. The width of the continental shelf in the area of ​​the Ayano-Okhotsk coast is approximately 100 miles, in the area of ​​Udskaya Bay - 140 miles. Between the meridians of Okhotsk and Magadan its width increases to 200 miles. On the western edge of the sea basin there is the island sandbank of Sakhalin, on the eastern edge there is the mainland sandbank of Kamchatka. The shelf occupies about 22% of the bottom area. The rest, most (about 70%) of the sea is located within the continental slope (from 200 to 1500 m), on which individual underwater hills, depressions and trenches are distinguished.
The deepest southern part of the sea, deeper than 2500 m, representing the bed area, occupies 8% of the total area. It stretches as a strip along the Kuril Islands, gradually narrowing from 200 km against the island. Iturup up to 80 km against the Krusenstern Strait. Great depths and significant bottom slopes distinguish the southwestern part of the sea from the northeastern part, which lies on the continental shallows.
Of the large elements of the bottom relief of the central part of the sea, two underwater hills stand out - the Academy of Sciences of the USSR and the Institute of Oceanology. Together with the protrusion of the continental slope, they determine the division of the sea basin into three basins: the northeastern TINRO depression, the northwestern Deryugin depression and the southern deep-sea Kuril Basin. The depressions are connected by gutters: Makarov, P. Schmidt and Lebed. To the northeast of the TINRO depression, the Shelikhov Bay trench extends.

Kamchatka, race on the shores of the Sea of ​​Okhotsk, Berengia 2013

The deepest TINRO depression is located west of Kamchatka. Its bottom is a plain lying at a depth of about 850 m with a maximum depth of 990 m. The Deryugin Depression is located east of the underwater base of Sakhalin. Its bottom is a flat plain, raised at the edges, lying on average at a depth of 1700 m, the maximum depth of the depression is 1744 m. The deepest is the Kuril Basin. This is a huge flat plain lying at a depth of about 3300 m. Its width in the western part is about 120 miles, and its length in a northeast direction is about 600 miles.

The hill of the Institute of Oceanology has a rounded outline; it is elongated in the latitudinal direction for almost 200 miles, and in the meridional direction for about 130 miles. The minimum depth above it is about 900 m. The heights of the USSR Academy of Sciences are cut by the tops of underwater valleys. A remarkable feature of the topography of the hills is the presence of flat peaks that occupy a large area.

CLIMATE OF THE SEA OF OKHOTSK
By its location, the Sea of ​​Okhotsk is located in the monsoon climate zone of temperate latitudes, which is significantly influenced by the physical and geographical features of the sea. Thus, a significant part of it in the west extends deep into the mainland and lies relatively close to the cold pole of the Asian landmass, so the main source of cold for the Sea of ​​Okhotsk is in the west, and not in the north. The relatively high ridges of Kamchatka make it difficult for warm Pacific air to penetrate. Only in the southeast and south is the sea open to the Pacific Ocean and the Sea of ​​Japan, from where a significant amount of heat enters it. However, the influence of cooling factors is stronger than warming ones, so the Sea of ​​Okhotsk as a whole is the coldest of the Far Eastern seas. At the same time, its large meridional extent causes significant spatial differences in synoptic conditions and meteorological indicators in each season. In the cold part of the year, from October to April, the sea is affected by the Siberian Anticyclone and the Aleutian Low. The influence of the latter extends mainly to the southeastern part of the sea. This distribution of large-scale pressure systems determines the dominance of strong, stable northwestern and northern winds, often reaching storm force. Little wind and calm are almost completely absent, especially in January and February. In winter, wind speed is usually 10-11 m/s.

The dry and cold Asian winter monsoon significantly cools the air over the northern and northwestern regions of the sea. In the coldest month (January), the average air temperature in the northwest of the sea is −20–25°, in the central regions −10–15°, only in the southeastern part of the sea it is −5–6°, which is explained by the warming influence Pacific Ocean.

The autumn-winter season is characterized by the occurrence of cyclones of predominantly continental origin. They entail stronger winds and sometimes a drop in air temperature, but the weather remains clear and dry, as they bring in continental air from the cooled mainland of Asia. In March - April, a restructuring of large-scale pressure fields occurs. The Siberian anticyclone is collapsing, and the Honolulu high is intensifying. As a result, during the warm season (from May to October), the Sea of ​​Okhotsk is influenced by the Honolulu High and the low pressure area located over Eastern Siberia. In accordance with this distribution of centers of atmospheric action, weak southeast winds prevail over the sea at this time. Their speed usually does not exceed 6-7 m/s. These winds are most common in June and July, although stronger northwest and northerly winds are sometimes observed during these months. In general, the Pacific (summer) monsoon is weaker than the Asian (winter) monsoon, since in the warm season the horizontal pressure gradients are small.

Nagaevo Bay

In summer, the air warms up unevenly over the entire sea. The average monthly air temperature in August decreases from southwest to northeast from 18° in the south, to 12–14° in the center and to 10–10.5° in the northeast of the Sea of ​​Okhotsk. In the warm season, oceanic cyclones often pass over the southern part of the sea, which is associated with increased winds to storm winds, which can last up to 5-8 days. The predominance of south-eastern winds in the spring-summer season leads to significant cloudiness, precipitation, and fog. Monsoon winds and stronger winter cooling of the western part of the Sea of ​​Okhotsk compared to the eastern part are important climatic features of this sea.
Quite a lot of mostly small rivers flow into the Sea of ​​Okhotsk, therefore, with such a significant volume of its waters, the continental flow is relatively small. It is approximately 600 km3/year, with about 65% coming from the Amur. Other relatively large rivers - Penzhina, Okhota, Uda, Bolshaya (in Kamchatka) - bring significantly less fresh water to the sea. It arrives mainly in spring and early summer. At this time, the influence of continental runoff is most noticeable, mainly in the coastal zone, near the mouths of large rivers.

Geographical location, large meridian length, monsoon wind changes and good connection between the sea and the Pacific Ocean through the Kuril Straits are the main natural factors that most significantly influence the formation of the hydrological conditions of the Sea of ​​Okhotsk. The amounts of heat inflow and outflow into the sea are determined mainly by radiation heating and cooling of the sea. The heat brought by Pacific waters is of subordinate importance. However, for the water balance of the sea, the arrival and flow of water through the Kuril Straits plays a decisive role. The details and quantitative indicators of water exchange through the Kuril Straits have not yet been sufficiently studied, however, the main routes of water exchange through the straits are known. The flow of surface Pacific waters into the Sea of ​​Okhotsk occurs mainly through the northern straits, in particular through the First Kuril Strait. In the straits of the middle part of the ridge, both the influx of Pacific waters and the outflow of Okhotsk waters are observed. Thus, in the surface layers of the Third and Fourth Kuril Straits, apparently, there is a drainage of water from the Sea of ​​Okhotsk, while in the bottom layers there is an influx, and in the Bussol Strait, on the contrary: in the surface layers there is an influx, in the deep layers there is a runoff. In the southern part of the ridge, mainly through the Ekaterina and Frieze straits, water predominantly drains from the Sea of ​​Okhotsk. The intensity of water exchange through the straits can vary significantly. In general, in the upper layers of the southern part of the Kuril ridge, the flow of Sea of ​​Okhotsk waters predominates, and in the upper layers of the northern part of the ridge, the influx of Pacific waters occurs. In the deep layers, the influx of Pacific waters generally predominates.
The influx of Pacific waters largely affects the distribution of temperature, salinity, formation of the structure and general circulation of the waters of the Sea of ​​​​Okhotsk.

Cape Stolbchaty, Kunashir Island, Kuril Islands

Hydrological characteristics.
Sea surface water temperatures generally decrease from south to north. In winter, almost everywhere the surface layers are cooled to a freezing temperature of −1.5–1.8°. Only in the southeastern part of the sea does it remain around 0°, and near the northern Kuril Straits, the water temperature under the influence of Pacific waters penetrating here reaches 1-2°.

Spring warming at the beginning of the season mainly leads to the melting of ice, only towards the end of it does the water temperature begin to rise. In summer, the distribution of water temperature on the sea surface is quite varied (Fig. 39). In August, the waters adjacent to the island are the warmest (up to 18-19°). Hokkaido. In the central regions of the sea, the water temperature is 11-12°. The coldest surface waters are observed near the island. Iona, near Cape Pyagin and near the Krusenstern Strait. In these areas, the water temperature is between 6-7°. The formation of local centers of increased and decreased water temperatures on the surface is mainly associated with the redistribution of heat by currents.

The vertical distribution of water temperature varies from season to season and from place to place. In the cold season, temperature changes with depth are less complex and varied than in warm seasons. In winter, in the northern and central regions of the sea, water cooling extends to horizons of 100–200 m. The water temperature is relatively uniform and drops from −1.7–1.5° on the surface to −0.25° at horizons of 500–600 m, deeper rises to 1-2° in the southern part of the sea, near the Kuril Straits the water temperature from 2.5-3.0° on the surface drops to 1.0-1.4° at horizons of 300-400 m and then gradually rises to 1, 9-2.4° at the bottom.

In summer, surface waters are heated to a temperature of 10-12°. In the subsurface layers, the water temperature is slightly lower than on the surface. A sharp decrease in temperature to values ​​of −1.0–1.2° is observed between horizons of 50–75 m; deeper to horizons of 150–200 m the temperature rises to 0.5–1.0°, and then its increase occurs more smoothly and at at horizons of 200–250 m it is 1.5–2.0°. From here the water temperature remains almost unchanged to the bottom. In the southern and southeastern parts of the sea, along the Kuril Islands, the water temperature from 10-14° on the surface drops to 3-8° at a horizon of 25 m, then to 1.6-2.4° at a horizon of 100 m and to 1 .4-2.0° at the bottom. The vertical distribution of temperature in summer is characterized by a cold intermediate layer - a remnant of the winter cooling of the sea (see Fig. 39). In the northern and central regions of the sea, the temperature is negative and only near the Kuril Straits it has positive values. In different areas of the sea, the depth of the cold intermediate layer is different and varies from year to year.

The distribution of salinity in the Sea of ​​Okhotsk changes relatively little over the seasons and is characterized by its increase in the eastern part, which is under the influence of Pacific waters, and its decrease in the western part, desalinated by continental runoff (Fig. 40). In the western part, the salinity on the surface is 28–31‰, and in the eastern part it is 31–32‰ and more (up to 33‰ near the Kuril ridge). In the northwestern part of the sea, due to desalination, the salinity on the surface is 25‰ or less, and the thickness of the desalinated layer is about 30-40 m.
Salinity increases with depth in the Sea of ​​Okhotsk. At horizons of 300–400 m in the western part of the sea, salinity is 33.5‰, and in the eastern part it is about 33.8‰. At a horizon of 100 m, salinity is 34.0‰ and further towards the bottom it increases slightly - by only 0.5-0.6‰. In individual bays and straits, the value of salinity and its stratification may differ significantly from the open sea, depending on local hydrological conditions.

Temperature and salinity determine the magnitude and density distribution of the waters of the Sea of ​​Okhotsk. Accordingly, denser waters are observed in winter in the northern and central ice-covered areas of the sea. The density is somewhat lower in the relatively warm Kuril region. In summer, the density of water decreases, its lowest values ​​are confined to zones of influence of coastal runoff, and the highest are observed in areas of distribution of Pacific waters. Density increases with depth. In winter, it rises relatively slightly from the surface to the bottom. In summer, its distribution depends in the upper layers on temperature values, and in the middle and lower horizons on salinity. In summer, a noticeable density stratification of waters is created vertically, the density increases especially significantly at horizons of 25-35-50 m, which is associated with the heating of waters in open areas and desalination near the coast.

Cape Nyuklya (sleeping Dragon) near Magadan

The possibilities for the development of mixing of waters in the Sea of ​​Okhotsk are largely related to the peculiarities of the vertical distribution of oceanological characteristics. Wind mixing occurs during the ice-free season. It occurs most intensely in spring and autumn, when strong winds blow over the sea, and the stratification of waters is not yet very pronounced. At this time, wind mixing extends to a horizon of 20-25 m from the surface. Strong cooling and powerful ice formation in autumn-winter contribute to the development of convection in the Sea of ​​Okhotsk. However, it flows differently in its different areas, which is explained by the peculiarities of the bottom topography, climatic differences, the flow of Pacific waters and other factors. Thermal convection in most of the sea penetrates up to 50-60 m, since the summer heating of surface waters, and in zones influenced by coastal runoff and significant desalination, cause vertical stratification of water, which is most pronounced at these horizons. The increase in the density of surface waters due to cooling and the resulting convection are not able to overcome the maximum stability located at the mentioned horizons. In the southeastern part of the sea, where Pacific waters predominantly spread, a relatively weak vertical stratification is observed, so thermal convection extends here to horizons of 150-200 m, where it is limited by the density structure of the waters.
Intense ice formation over most of the sea stimulates enhanced thermohaline winter vertical circulation. At depths of up to 250-300 m, it spreads to the bottom, and its penetration to greater depths is prevented by the maximum stability that exists here. In areas with rugged bottom topography, the spread of density mixing into the lower horizons is facilitated by the sliding of water along the slopes. In general, the Sea of ​​Okhotsk is characterized by good mixing of its waters.

Features of the vertical distribution of oceanological characteristics, mainly water temperature, indicate that the Sea of ​​Okhotsk is characterized by a subarctic structure of waters, in which cold and warm intermediate layers are well defined in summer. A more detailed study of the subarctic structure in this sea showed that there are Sea of ​​Okhotsk, Pacific and Kuril varieties of the subarctic water structure. Although they have the same vertical structure, they have quantitative differences in the characteristics of water masses.

Based on the analysis of T and S-curves in combination with consideration of the vertical distribution of oceanological characteristics in the Sea of ​​Okhotsk, the following water masses are distinguished. Surface water mass that has spring, summer and autumn modifications. It represents the upper maximum of stability, determined mainly by temperature. This water mass is characterized by temperature and salinity values ​​corresponding to each season, on the basis of which its mentioned modifications are distinguished.
The Sea of ​​Okhotsk water mass is formed in winter from surface water and in spring, summer and autumn appears in the form of a cold intermediate layer, flying between horizons of 40-150 m. This water mass is characterized by a fairly uniform salinity (about 32.9-31.0‰) and varying from place to place temperature. In most of the sea, its temperature is below 0° and reaches −1.7°, and in the area of ​​the Kuril Straits it is above 1°.

The intermediate water mass is formed mainly due to the sinking of water along the slopes of the bottom; within the sea it is located from 100–150 to 400–700 m and is characterized by a temperature of 1.5° and a salinity of 33.7‰. This water mass is distributed almost everywhere, except for the northwestern part of the sea, Shelikhov Bay and some areas along the coast of Sakhalin, where the Sea of ​​Okhotsk water mass reaches the bottom. The thickness of the intermediate water mass layer generally decreases from south to north.

The deep Pacific water mass is the water of the lower part of the warm layer of the Pacific Ocean, entering the Sea of ​​Okhotsk at horizons below 800-2000 m, i.e. below the depth of the waters descending in the straits, and appears in the sea as a warm intermediate layer. This water mass is located at horizons of 600–1350 m, has a temperature of 2.3° and a salinity of 34.3‰. However, its characteristics change in space. The highest values ​​of temperature and salinity are observed in the northeastern and partly in the northwestern regions, which is associated here with rising waters, and the lowest values ​​of the characteristics are characteristic of the western and southern regions, where subsidence of waters occurs.
The water mass of the Southern Basin is of Pacific origin and represents deep water of the northwestern part of the Pacific Ocean from a horizon of 2300 m, corresponding to the maximum depth of the threshold in the Kuril Straits (Bussol Strait). The water mass in question generally fills the named basin from a horizon of 1350 m to the bottom. It is characterized by a temperature of 1.85° and a salinity of 34.7‰, which vary only slightly with depth.
Among the identified water masses, the Sea of ​​Okhotsk and the deep Pacific are the main ones and differ from each other not only in thermohaline, but also in hydrochemical and biological parameters.

Under the influence of winds and the influx of water through the Kuril Straits, the characteristic features of the system of non-periodic currents of the Sea of ​​Okhotsk are formed (Fig. 41). The main one is a cyclonic system of currents that covers almost the entire sea. It is caused by the predominance of cyclonic circulation of the atmosphere over the sea and the adjacent part of the Pacific Ocean. In addition, stable anticyclonic gyres and vast areas of cyclonic water circulation can be traced in the sea.

At the same time, a narrow strip of stronger coastal currents stands out quite clearly, which, continuing each other, seem to go around the sea coastline counterclockwise; warm Kamchatka Current directed north to Shelikhov Bay; flow of a western and then southwestern direction along the northern and northwestern shores of the sea; the stable East Sakhalin Current going south, and the rather strong Soya Current entering the Sea of ​​Okhotsk through the La Perouse Strait.
On the southeastern periphery of the cyclonic circulation of the Central part of the sea, a branch of the Northeast Current is distinguished, opposite in direction to the Kuril Current (or Oyashio) in the Pacific Ocean. As a result of the existence of these flows, stable areas of convergence of currents are formed in some of the Kuril straits, which leads to lowering of waters and has a significant impact on the distribution of oceanological characteristics not only in the straits, but also in the sea itself. And finally, another feature of the circulation of the waters of the Sea of ​​​​Okhotsk is two-way stable currents in most of the Kuril Straits.

Non-periodic currents on the surface of the Sea of ​​Okhotsk are most intense off the western coast of Kamchatka (11-20 cm/s), in the Sakhalin Gulf (30-45 cm/s), in the Kuril Straits area (15-40 cm/s), over the Southern Basin ( 11-20 cm/s) and during the Soya (up to 50-90 cm/s). In the central part of the cyclonic region, the intensity of horizontal transport is much less than at its periphery. In the central part of the sea, velocities vary from 2 to 10 cm/s, with the predominant velocities being less than 5 cm/s. A similar picture is observed in Shelikhov Bay, rather strong currents off the coast (up to 20-30 cm/s) and low speeds in the central part of the cyclonic gyre.

Periodic (tidal) currents are also well expressed in the Sea of ​​Okhotsk. Here their various types are observed: semidiurnal, diurnal and mixed with a predominance of semidiurnal or diurnal components. The speeds of tidal currents vary - from a few centimeters to 4 m/s. Far from the coast, current speeds are low (5-10 cm/s). In straits, bays and off the coast, the speeds of tidal currents increase significantly, for example in the Kuril Straits they reach 2-4 m/s.
The tides of the Sea of ​​Okhotsk are very complex. The tidal wave enters from the south and southeast from the Pacific Ocean. The semidiurnal wave moves north, and at the 50° parallel it divides into two branches: the western one turns to the northwest, forming amphidromic areas north of Cape Terpeniya and in the northern part of Sakhalin Bay, the eastern one moves towards Shelikhov Bay, at the entrance to which it appears another amphidromy. The daily wave also moves north, but at the latitude of the northern tip of Sakhalin it is divided into two parts: one enters Shelikhov Bay, the other reaches the northwestern coast.

There are two main types of tides in the Sea of ​​Okhotsk: daily and mixed. The most common are diurnal tides. They are observed in the Amur Estuary, Sakhalin Bay, on the Kuril Islands, off the western coast of Kamchatka and in the Gulf of Penzhin. Mixed tides are observed on the northern and northwestern coasts of the sea and in the area of ​​the Shantar Islands.
The highest tides were recorded in Penzhinskaya Bay near Astronomichesky Cape (up to 13 m). These are the highest tides for the entire coast of the USSR. In second place is the area of ​​the Shantar Islands, where the tide exceeds 7 m. The tides in the Sakhalin Bay and the Kuril Straits are very significant. In the northern part of the sea, the tides reach up to 5 m. The lowest tides were observed off the eastern coast of Sakhalin, in the area of ​​the La Perouse Strait. In the southern part of the sea, the tide ranges from 0.8 to 2.5 m. In general, tidal fluctuations in the level in the Sea of ​​Okhotsk are very significant and have a significant impact on its hydrological regime, especially in the coastal zone.
In addition to tidal fluctuations, surge level fluctuations are also well developed here. They occur mainly when deep cyclones pass over the sea. Surge increases in level reach 1.5-2 m. The largest surges are noted on the coast of Kamchatka and in Terpeniya Bay.

The considerable size and great depths of the Sea of ​​Okhotsk, frequent and strong winds above it determine the development of large waves here. The sea is especially rough in the fall, and in ice-free areas even in winter. These seasons account for 55-70% of storm waves, including those with wave heights of 4-6 m, and the highest wave heights reach 10-11 m. The most turbulent are the southern and south-eastern regions of the sea, where the average frequency of storm waves is 35 -50%, and in the northwestern part it decreases to 25-30%. With strong waves, a crowd forms in the straits between the Kuril Islands and between the Shantar Islands.

Severe and long winters with strong northwest winds contribute to the development of intense ice formation in the Sea of ​​Okhotsk. The ice of the Sea of ​​Okhotsk is exclusively local in origin. Here there are both fixed ice (fast ice) and floating ice, which represents the main form of sea ice. Ice is found in varying quantities in all areas of the sea, but in summer the entire sea is cleared of ice. The exception is the area of ​​the Shantar Islands, where ice can persist in the summer.
Ice formation begins in November in the bays and lips of the northern part of the sea, in the coastal part of the island. Sakhalin and Kamchatka. Then ice appears in the open part of the sea. In January and February, ice covers the entire northern and middle part of the sea. In normal years, the southern border of the relatively stable ice cover runs, curving north, from the La Perouse Strait to Cape Lopatka. The extreme southern part of the sea never freezes. However, thanks to the winds, significant masses of ice are carried into it from the north, often accumulating near the Kuril Islands.

From April to June, destruction and gradual disappearance of the ice cover occurs. On average, sea ice disappears at the end of May - beginning of June. The northwestern part of the sea, due to currents and the configuration of the shores, is most clogged with ice, which remains there until July. Consequently, the ice cover in the Sea of ​​Okhotsk remains for 6-7 months. Floating ice covers more than three quarters of the sea surface. The compact ice of the northern part of the sea poses a serious obstacle to navigation even for icebreakers. The total duration of the ice period in the northern part of the sea reaches 280 days a year.

The southern coast of Kamchatka and the Kuril Islands belong to areas with little ice cover; here the ice lasts on average no more than three months a year. The thickness of the ice that grows during the winter reaches 0.8–1.0 m. Strong storms and tidal currents break up the ice cover in many areas of the sea, forming hummocks and large open waters. In the open part of the sea, continuous, motionless ice is never observed; here the ice usually drifts in the form of vast fields with numerous leads. Some of the ice from the Sea of ​​Okhotsk is carried into the ocean, where it almost immediately collapses and melts. In severe winters, floating ice is pressed against the Kuril Islands by northwestern winds and clogs some straits. Thus, in winter there is no place in the Sea of ​​Okhotsk where encountering ice would be completely excluded.

Hydrochemical conditions.
Due to constant water exchange with the Pacific Ocean through the deep Kuril Straits, the chemical composition of the waters of the Sea of ​​Okhotsk is generally no different from the ocean. The values ​​and distribution of dissolved gases and nutrients in open areas of the sea are determined by the influx of Pacific waters, and in the coastal part, coastal runoff has a certain influence.

The Sea of ​​Okhotsk is rich in oxygen, but its content is not the same in different areas of the sea and changes with depth. A large amount of oxygen is dissolved in the waters of the northern and central parts of the sea, which is explained by the abundance of oxygen-producing phytoplankton here. In particular, in the central part of the sea, the development of plant organisms is associated with the rise of deep waters in zones of convergence of currents. The waters of the southern regions of the sea contain less oxygen, since the Pacific waters that are relatively poor in phytoplankton flow here. The highest content (7-9 ml/l) of oxygen is observed in the surface layer; deeper it gradually decreases and at a horizon of 100 m it is 6-7 ml/l, and at a horizon of 500 m it is 3.2-4.7 ml/l. then the amount of this gas decreases very quickly with depth and reaches a minimum at horizons of 1000–1300 m (1.2–1.4 ml/l), but in deeper layers it increases to 1.3–2.0 ml/l. The oxygen minimum is confined to the deep Pacific water mass.

The surface layer of the sea contains 2-3 µg/l of nitrites and 3-15 µg/l of nitrates. With depth, their concentration increases, and the content of nitrites reaches a maximum at horizons of 25-50 m, and the amount of nitrates here increases sharply, but the greatest values ​​of these substances are observed at horizons of 800-1000 m, from where they slowly decrease towards the bottom. The vertical distribution of phosphates is characterized by an increase in their content with depth, especially noticeable from horizons of 50-60 m, and the maximum concentration of these substances is observed in the bottom layers. In general, the amount of nitrites, nitrates and phosphates dissolved in sea waters increases from north to south, which is mainly due to the rise of deep waters. Local features of hydrological and biological conditions (water circulation, tides, degree of development of organisms, etc.) form the regional hydrochemical features of the Sea of ​​Okhotsk.

Economic use.
The economic importance of the Sea of ​​Okhotsk is determined by the use of its natural resources and maritime transport. The main wealth of this sea is game animals, primarily fish. Here, mainly its most valuable species are caught - salmon (chum salmon, pink salmon, sockeye salmon, coho salmon, chinook salmon) and their caviar. Currently, salmon stocks have decreased, and therefore their production has decreased. Fishing for this fish is limited. In addition, herring, cod, flounder and other types of marine fish are caught in the sea in limited quantities. The Sea of ​​Okhotsk is the main crab fishing area. Squid are being harvested in the sea. One of the largest herds of fur seals is concentrated on the Shantar Islands, the hunting of which is strictly regulated.

Sea transport lines connect the Okhotsk ports of Magadan, Nagaevo, Ayan, Okhotsk with other Soviet and foreign ports. Various cargoes arrive here from different regions of the Soviet Union and foreign countries.

The largely studied Sea of ​​Okhotsk still needs to solve various natural problems. In terms of their hydrological aspects, studies of water exchange between the sea and the Pacific Ocean, general circulation, including vertical movements of water, their fine structure and eddy-like movements, ice conditions, especially in the prognostic direction of the timing of ice formation, the direction of ice drift, etc., occupy an essential place. The solution to these and other problems will contribute to the further development of the Sea of ​​Okhotsk.

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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.
Shamraev Yu. I., Shishkina L. A. Oceanology. L.: Gidrometeoizdat, 1980.
Lithosphere of the Sea of ​​Okhotsk
The Sea of ​​Okhotsk in the book: A. D. Dobrovolsky, B. S. Zalogin. Seas of the USSR. Publishing house Moscow. University, 1982.
Leontyev V.V., Novikova K.A. Toponymic dictionary of the north-east of the USSR. - Magadan: Magadan Book Publishing House, 1989, page 86
Leonov A.K. Regional oceanography. - Leningrad, Gidrometeoizdat, 1960. - T. 1. - P. 164.
Wikipedia website.
Magidovich I. P., Magidovich V. I. Essays on the history of geographical discoveries. - Enlightenment, 1985. - T. 4.
http://www.photosight.ru/
photo: O. Smoliy, A. Afanasyev, A. Gill, L. Golubtsova, A. Panfilov, T. Selena.

The Sea of ​​Okhotsk is a semi-enclosed sea located in the northern hemisphere, part of the Pacific Ocean, washing the shores of Russia and Japan.

Previously, this sea was called “Kamchatka”. The Japanese called this sea "Hokkai", which literally translates as "North Sea", but the traditional name eventually changed to the Sea of ​​Okhotsk.

What rivers flow into

The following large rivers flow into the Sea of ​​Okhotsk:

• Kukhtui (a river whose length reaches 384 kilometers, it is located in the Khabarovsk Territory, just like the Okhota River);
  
• Okhota (a small river in the Khabarovsk Territory, the length of which reaches almost 400 kilometers);
• Amur (the length of the river reaches almost 2900 km, which makes this waterway quite large and important in Eastern Russia and China for infrastructure).

Relief of the Sea of ​​Okhotsk

The western part of the bottom is a flat slab and is located at a fairly shallow depth. In the very center there are large depressions. However, the maximum depth was recorded in the so-called Kuril Basin, which is located in the eastern part of the Sea of ​​Okhotsk. The bottom can be sandy, rocky, muddy-sandy.

The seashores are mostly high and rocky. In the southwest of Kamchatka the shores have low relief. There are volcanoes at the bottom of the Sea of ​​Okhotsk, and there are also on the islands. 70 are considered extinct, 30 are considered active.

The southeastern part of the sea almost never freezes - even in winter, which cannot be said about the northern part of the sea, where ice persists from October to June. The northern coast of the sea is heavily indented, which is why many natural bays have been created here, the largest of which is called Sherikhov Bay. In the west of the sea there are also many bays, the largest of which are the Shantar Sea and Sakhalin Bay.

Cities

On the shores of the Sea of ​​Okhotsk there is a small town called Okhotsk, which became the first Russian settlement built on the shores of the Pacific Ocean. Magadan is considered one of the largest cities on the shores of the Sea of ​​Okhotsk with a population of more than 90 thousand inhabitants.

Kholmsk photo

On the seashore there is also a relatively small town of Kholmsk with a population of 28 thousand inhabitants. Well, the last “big city” on the Sea of ​​Okhotsk can be called Korsakov with a population of 33 thousand people. The city is actively involved in fishing and fish processing.

Flora and fauna of the Sea of ​​Okhotsk

The number of fish species in the Sea of ​​Okhotsk is large; there has always been a fair amount of it, which is why the sea has become an important industrial site. The largest quantities in the Sea of ​​Okhotsk are herring, capelin, salmon, pollock and navaga. Among other valuable seafood, one can also highlight Kamchatka crab - they reach truly enormous sizes and are a delicacy for humans.

Beluga whale in the Sea of ​​Okhotsk photo

Sea urchins, starfish, shrimp and crabs, mussels, jellyfish, and corals live here. The Kamchatka crab is one of the largest representatives of crustaceans in the Far Eastern waters.

As in many northern waters, the Sea of ​​Okhotsk is home to several species of whales, including the rare fin whale, as well as the largest creatures on the planet to ever exist, blue whales. The waters of the sea are inhabited by beluga whales, seals and seals.

depths of the Sea of ​​Okhotsk photo

The world of birds is diverse and numerous. On the islands of the Sea of ​​Okhotsk, large colonies of gulls, cormorants, guillemots, guillemots, mottled guillemots, petrels, geese, etc. nest in large colonies.

birds on the Sea of ​​Okhotsk photo

Sea vegetation: brown and green algae, red algae, kelp, in some places there are abundant thickets of sea grass - zoster.

Characteristics of the Sea of ​​Okhotsk

The area of ​​the Sea of ​​Okhotsk reaches 1,603,000 square kilometers, and its volume exceeds 1,300,000 cubic meters. The average depth of the sea is quite large - approximately 1,700 meters, and the deepest point of the seabed is located at a depth of 3,916 meters.

In summer, the sea surface temperature is 18 degrees Celsius. And in winter it is colder - 2 degrees Celsius, and sometimes it can drop to minus temperatures -1.8 degrees. As for the climate, it is monsoonal, very harsh due to the northern winds, only in the south the air temperature is relatively high.

Sea of ​​Okhotsk in winter photo

If we compare the Sea of ​​Okhotsk with the neighboring seas: the Japanese and Bering seas, then it will be the coldest of them. In winter, the Sea of ​​Okhotsk is tormented by strong northern winds and thereby makes the climate even more severe. The minimum air temperature comes with January and reaches -25 degrees on average. In summer, the temperature rarely exceeds +15 degrees.

Quite often, storms occur on the Sea of ​​Okhotsk that last more than one week. They come to the southern part of the sea from the Pacific Ocean. The waves are high and the storms are long. In very severe winters, ice forms - both floating and also stationary. Ice floes float along Sakhalin and the Amur region, often even in summer.

Sakhalin photo

Coastal waters are the least saline and generally do not reach even 30%. But in the rest of the sea, the salt level sometimes reaches up to 34%. Surface waters are the least saline - no more than 32-33%, while already at depth the salinity exceeds 34%.

There are also islands in the Sea of ​​Okhotsk, but their number is extremely small. The largest one is Sakhalin Island. Most of the islands are located in a seismically active zone.