Origin of the sea basin of the Sea of Okhotsk. Importance of the Sea of Okhotsk for Russia. Video: Sea of Okhotsk
Sea of Okhotsk located in the northwestern part Pacific Ocean off the coast of Asia and is separated from the ocean by the chain of the Kuril Islands and the Kamchatka Peninsula. From the south and west, it is bounded by the coast of Hokkaido, the eastern coast of Sakhalin Island and the coast of the Asian mainland. The sea is significantly elongated from southwest to northeast within a spherical trapezoid with coordinates 43°43"–62°42" N. sh. and 135°10"–164°45"E. e. The greatest length of the water area in this direction is 2463 km, and the width reaches 1500 km. The surface area of the sea surface is 1603 thousand km2, the length of the coastline is 10460 km, and the total volume of sea water is 1316 thousand km3. In my own way geographic location it belongs to the marginal seas of the mixed continental-marginal type. The Sea of Okhotsk is connected to the Pacific Ocean by the numerous straits of the Kuril Islands, and to the Sea of Japan through the La Perouse Strait and through the Amur Estuary by the Nevelskoy and Tatar Straits. The average value of the sea depth is 821 m, and the largest is 3521 m (in the Kuril basin).
The main morphological zones in the bottom topography are: the shelf (the continental and insular shoals of Sakhalin Island), the continental slope, on which separate underwater elevations, depressions and islands stand out, and the deep-water basin. The shelf zone (0–200 m) is 180–250 km wide and occupies about 20% of the sea area. Wide and gentle, in the central part of the basin, the continental slope (200–2000 m) occupies about 65%, and the deepest basin (more than 2500 m), located in the southern part of the sea, occupies 8% of the sea area. Within the area of the continental slope, several elevations and depressions are distinguished, where the depths change dramatically (the uplift of the Academy of Sciences, the uplift of the Institute of Oceanology and the Deryugin Basin). The bottom of the deep-water Kuril Basin is a flat abyssal plain, and the Kuril Ridge is a natural threshold separating the sea basin from the ocean.
The Amur Estuary, Nevelskoy in the north and Laperouse in the south straits connect the Sea of Okhotsk with the Sea of Japan, and the numerous Kuril Straits with the Pacific Ocean. The chain of the Kuril Islands is separated from the island of Hokkaido by the Strait of Treason, and from the Kamchatka Peninsula by the First Kuril Strait. Straits connecting the Sea of Okhotsk with adjacent areas Sea of Japan and the Pacific Ocean, provide the possibility of water exchange between the basins, which, in turn, have a significant impact on the distribution hydrological characteristics. The Nevelskoy and La Perouse straits are relatively narrow and shallow, which is the reason for the relatively weak water exchange with the Sea of Japan. The straits of the Kuril Islands, which stretch for about 1200 km, on the contrary, are deeper, and their total width is 500 km. The deepest are the Bussol (2318 m) and Krusenstern (1920 m) straits.
Northwest coast Sea of Okhotsk practically devoid of large bays, and the northern one is significantly indented. The Tauiskaya Bay protrudes into it, the coasts of which are indented with bays and bays. The bay is separated from the Sea of Okhotsk by the Koni Peninsula.
The largest bay of the Sea of Okhotsk lies in its northeastern part, extending 315 km into the mainland. This is Shelikhov Bay with Gizhiginskaya and Penzhinskaya lips. The Gizhiginskaya and Penzhinskaya bays are separated by the elevated Taigonos Peninsula. In the southwestern part of Shelikhov Bay, north of the Pyagin Peninsula, there is a small Yamskaya Bay.
The western coast of the Kamchatka Peninsula is leveled and practically devoid of bays.
The shores of the Kuril Islands are complex in outline and form small bays. From the Sea of Okhotsk side, the most large bays are located near the island of Iturup, which are deep-water and have a very intricately dissected bottom.
Quite a few mostly small rivers flow into the Sea of Okhotsk, therefore, with a significant volume of its waters, the continental runoff is relatively small. It is equal to about 600 km3 per year, while about 65% of the flow comes from the Amur River. Others comparatively major rivers- Penzhina, Okhota, Uda, Bolshaya (in Kamchatka) - bring much less to the sea fresh water. The flow comes mainly in spring and early summer. At this time, its greatest influence is felt mainly in the coastal zone, near the mouth areas of large rivers.
coast Sea of Okhotsk in different areas belong to different geomorphological types. For the most part, these are abrasion shores altered by the sea, and only on the Kamchatka Peninsula and Sakhalin Island are accumulative shores found. In general, the sea is surrounded by high and steep shores. In the north and northwest, rocky ledges descend directly to the sea. The coasts along the Sakhalin Bay 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 are somewhat elevated.
According to the features of the composition and distribution bottom sediments three main zones can be distinguished: the central one, which is composed mainly of diatomaceous silt, silty-argillaceous and partially clayey silts; the distribution zone of hemipelagic and pelagic clays in the western, eastern and northern parts of the Sea of Okhotsk; as well as the distribution zone of inequigranular sands, gravel sandstones and silts - in the northeast of the Sea of Okhotsk. Coarse clastic material, which is the result of ice rafting, is ubiquitous.
The Sea of Okhotsk is located in the monsoon zone. climate temperate latitudes. A significant part of the sea in the west deeply protrudes into the mainland and lies relatively close to the cold pole of the Asian land, so the main source of cold for the Sea of Okhotsk is located to the west of it. Relatively high ridges Kamchatka impedes the penetration of warm Pacific air. 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 factors, so the Sea of Okhotsk is generally cold.
In the cold part of the year (from October to April), the Siberian anticyclone and the Aleutian low act on the sea. The influence of the latter extends mainly to the southeastern part of the sea. This distribution of large-scale baric systems causes strong persistent northwesterly and northerly winds, often reaching storm strength. In winter, the wind speed is usually 10–11 m/s.
In the coldest month - January - the average air temperature in the north-west of the sea is -20 ... -25 ° С, in central regions- –10...–15°С, and in the southeastern part of the sea - –5...–6°С.
In autumn and winter, cyclones are predominantly of continental origin. They bring with them an increase in wind, sometimes a decrease in air temperature, but the weather remains clear and dry, as continental air comes from the cooled mainland. In March - April, large-scale baric fields are restructured, the Siberian anticyclone is destroyed, and the Hawaiian maximum is strengthened. As a result, during the warm season (from May to October), the Sea of Okhotsk is under the influence of the Hawaiian maximum and the area of low pressure located over Eastern Siberia. At the same time, weak southeasterly winds prevail over the sea. Their speed usually does not exceed 6–7 m/s. Most often, these winds are observed in June and July, although stronger northwesterly and northerly winds are sometimes observed in these months. In general, the Pacific (summer) monsoon is weaker than the Asian (winter) monsoon, since the horizontal pressure gradients are smoothed out in the warm season.
In summer, the average monthly air temperature in August decreases from the southwest to the northeast (from 18°C to 10–10.5°C).
During the warm season over southern part seas quite often pass tropical cyclones - typhoons. They are associated with an increase in wind to a storm, which can last up to 5–8 days. The predominance of southeasterly 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 this sea.
Geographical position, large extent along the meridian, monsoonal change of winds and good connection seas with the Pacific Ocean through the Kuril Straits are the main natural factors that most significantly affect the formation hydrological conditions Sea of Okhotsk.
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 upper layers of the southern part of the Kuril ridge, the runoff of the Sea of Okhotsk waters predominates, and in the upper layers of the northern part of the ridge, Pacific waters enter. In the deep layers, the inflow of Pacific waters prevails.
The inflow of Pacific waters significantly affects the distribution of temperature, salinity, and the formation of the structure and general circulation of the waters of the Sea of Okhotsk.
The following water masses are distinguished in the Sea of Okhotsk:
– surface water mass with spring, summer and autumn modifications. It is a thin heated layer 15–30 m thick, which limits the upper stability maximum, which is mainly determined by temperature;
– the Sea of Okhotsk water mass is formed from surface water in winter and manifests itself in spring, summer and autumn as a cold intermediate layer lying between 40–150 m horizons. This water mass is characterized by a fairly uniform salinity (31–32‰) and different temperatures;
- the intermediate water mass is formed mainly due to the descent of water along the underwater slopes, within the sea, ranging from 100–150 to 400–700 m, and is characterized by a temperature of 1.5 ° C and a salinity of 33.7‰. This water mass is distributed almost everywhere;
- 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 the horizons below 800–1000 m. This water mass is located at the horizons of 600–1350 m, has a temperature of 2.3 ° C and a salinity of 34.3 ‰.
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. This water mass fills the basin from the horizon of 1350 m to the bottom and is characterized by a temperature of 1.85 ° C and a salinity of 34.7 change only slightly with depth.
Water temperature on the sea surface decreases from south to north. In winter, almost everywhere, the surface layers cool down to a freezing temperature of –1.5...–1.8°C. Only in the southeastern part of the sea does it stay around 0°C, and near the northern Kuril Straits, under the influence of Pacific waters, the water temperature reaches 1–2°C.
Spring warming at the beginning of the season mainly goes 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 diverse. In August, the waters adjacent to the island of Hokkaido are warmest (up to 18–19°C). In the central regions of the sea, the water temperature is 11–12°С. The coldest surface waters are observed near Iona Island, near Cape Pyagin and near the Kruzenshtern Strait. In these areas, the water temperature is kept in the range of 6-7°C. The formation of local centers of increased and decreased water temperature 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, the change in temperature with depth is 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 ... 600 m, deeper it rises to 1–0°С, in the southern part of the sea and near the Kuril Straits, the water temperature drops from 2.5–3°С on the surface to 1–1.4°С at horizons of 300–400 m and further gradually rises to 1.9–2.4°C in the bottom layer.
In summer, surface waters are warmed up to a temperature of 10–12°C. In the subsurface layers, the water temperature is slightly lower than on the surface. A sharp decrease in temperature to –1...–1.2°С is observed between horizons of 50–75 m, deeper, to horizons of 150–200 m, the temperature quickly rises to 0.5–1°С, and then it rises more smoothly , and at the horizons of 200–250 m it is 1.5–2°С. Further, the temperature of the water almost does not change to the bottom. In the southern and southeastern parts of the sea, along the Kuril Islands, the water temperature drops from 10–14°С at the surface to 3–8°С at the 25 m horizon, then to 1.6–2.4°С at the 100 m horizon. and up to 1.4–2°C near 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 in it is negative, and only near the Kuril Straits does it have positive values. In different areas of the sea, the depth of the cold intermediate layer is different and varies from year to year.
Distribution salinity in the Sea of Okhotsk, relatively little changes with seasons. Salinity increases in the eastern part, which is under the influence of Pacific waters, and decreases in the western part, which is desalinated by continental runoff. In the western part, 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 freshening, the salinity on the surface is 25‰ or less, and the thickness of the freshened layer is about 30–40 m.
Salinity increases with depth in the Sea of Okhotsk. At the horizons of 300–400 m in the western part of the sea, the salinity is 33.5‰, and in the eastern part it is about 33.8‰. At a horizon of 100 m, salinity is 34‰ and further towards the bottom it increases slightly, by only 0.5–0.6‰.
In some bays and straits, the salinity value, its stratification can differ significantly from the waters high seas depending on local conditions.
In accordance with temperature and salinity, denser waters are observed in winter in the northern and central regions of the sea covered with ice. The density is somewhat less in the relatively warm Kuril region. In summer, the water density decreases, its lowest values are confined to the zones of influence of coastal runoff, and the highest values are observed in the 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 horizons. IN summer time a noticeable density stratification of waters along the vertical is created, the density increases especially noticeably at the horizons of 25–50 m, which is associated with the heating of waters in open areas and desalination near the coast.
Intense ice formation over most of the sea excites an enhanced thermohaline winter vertical circulation. At depths up to 250–300 m, it propagates to the bottom, and below it is prevented by the maximum stability that exists here. In areas with a rugged bottom topography, the spread of density mixing into the lower horizons is facilitated by the sliding of water along the slopes.
Under the influence of winds and water inflow through the Kuril Straits, character traits systems of non-periodic currents Sea of Okhotsk. The main one is the cyclonic system of currents, covering almost the entire sea. It is due to the predominance of cyclonic circulation of the atmosphere over the sea and the adjacent part of the Pacific Ocean. In addition, stable anticyclonic gyres can be traced in the sea.
Strong currents bypass the sea along the coastline counterclockwise: the warm Kamchatka Current, the stable East Sakhalin Current and the fairly strong Soya Current.
And finally, one more feature of the water circulation in the Sea of Okhotsk is two-way stable currents in most of the Kuril straits.
Currents on the surface of the Sea of Okhotsk are most intense near the western coast of Kamchatka (11–20 cm/s), in the Sakhalin Bay (30–45 cm/s), in the region of the Kuril Straits (15–40 cm/s), over the Kuril Basin (11 –20 cm/s) and during the Soya (up to 50–90 cm/s).
In the Sea of Okhotsk, various types of periodic tidal currents: semidiurnal, diurnal mixed with a predominance of semidiurnal or diurnal components. The velocities of tidal currents range from a few centimeters to 4 m/s. Away from the coast, the current velocities are low - 5–10 cm/s. In straits, bays and off the coast, their speeds increase significantly. For example, in the Kuril Straits, current velocities reach 2–4 m/s.
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 fluctuations in the level are also well developed here. They occur mainly during the passage of deep cyclones over the sea. Surge rises in the level reach 1.5–2 m. The largest surges are noted on the coast of Kamchatka and in the Gulf of Patience.
The significant size and great depths of the Sea of Okhotsk, frequent and strong winds over it determine the development of large waves here. The sea is especially stormy in autumn, and in some areas even in winter. These seasons account for 55–70% of storm waves, including those with wave heights of 4–6 m, and greatest heights waves reach 10–11 m. The most restless are the southern and southeastern regions of the sea, where the average frequency of storm waves is 35–40%, and in the northwestern part it decreases to 25–30%.
In ordinary years, the southern border of a 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, due to the winds, significant masses of ice are carried into it from the north, often accumulating near the Kuril Islands.
The ice cover in the Sea of Okhotsk lasts for 6-7 months. Floating ice covers more than 75% of the sea surface. Close-packed ice in the northern part of the sea presents 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. Part of the ice from the Sea of Okhotsk is carried into the ocean, where it breaks up and melts almost immediately.
Forecast resources hydrocarbons Sea of Okhotsk is estimated at 6.56 billion tons of oil equivalent, explored reserves - over 4 billion tons. The largest deposits on the shelves (along the coast of Sakhalin Island, the Kamchatka Peninsula, Khabarovsk Territory and Magadan region). The deposits of Sakhalin Island are the most studied. Exploration work on the shelf of the island began in the 70s. In the 20th century, by the end of the 1990s, seven large fields (6 oil and gas condensate and 1 gas condensate) and a small gas field in the Tatar Strait were discovered on the shelf of North-Eastern Sakhalin. The total gas reserves on the Sakhalin shelf are estimated at 3.5 trillion m3.
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Vegetation and animal world
are of great variety. In terms of stocks of commercial crab, the sea ranks first in the world. Salmon fish are of great value: chum salmon, pink salmon, coho salmon, chinook, sockeye - a source of red caviar. Intensive fishing is carried out for herring, pollock, flounder, cod, navaga, capelin, etc. Whales, seals, sea lions, fur seals live in the sea. The fishing of mollusks and sea urchins is gaining more and more interest. Various algae are ubiquitous in the littoral.
Due to the poor development of the adjacent territories, maritime transport has become of primary importance. Important sea routes lead to Korsakov on Sakhalin Island, Magadan, Okhotsk and other settlements.
the greatest anthropogenic load the areas of the Tauiskaya Bay in the northern part of the sea and the shelf areas of Sakhalin Island are affected. About 23 tons of oil products enter the northern part of the sea annually, 70–80% of which comes from river runoff. Pollutants enter the Tauyskaya Bay from onshore industrial and municipal facilities, and the wastewater from Magadan enters the coastal zone practically without treatment.
The shelf zone of Sakhalin Island is polluted by coal, oil and gas production enterprises, pulp and paper mills, fishing and processing vessels and enterprises, and sewage from municipal facilities. Annual receipt of oil products in southwestern part seas are estimated at about 1.1 thousand tons, with 75–85% of river runoff.
Petroleum hydrocarbons enter the Sakhalin Bay mainly with the runoff of the Amur River; therefore, their maximum concentrations, as a rule, are noted in the central and western parts bay along the axis of incoming Amur waters.
The eastern part of the sea - the shelf of the Kamchatka Peninsula - is polluted by river runoff, with which the main part of petroleum hydrocarbons enters the marine environment. In connection with the reduction of work at the fish canning enterprises of the peninsula since 1991, there has been a decrease in the volume of wastewater discharged into the coastal zone of the sea.
The northern part of the sea - Shelikhov Bay, Tauyskaya and Penzhinskaya bays - is the most polluted area of the sea with an average content of petroleum carbons in water 1–5 times higher than the permissible concentration limit. This is determined not only by the anthropogenic load on the water area, but also by the low average annual water temperatures and, consequently, the low ability of the ecosystem to self-purify. The highest level of pollution in the northern part of the Sea of Okhotsk was noted in the period from 1989 to 1991.
The southern part of the sea - the La Perouse Strait and the Aniva Bay - are subjected to intense oil pollution in the spring-summer period by commercial and fishing fleets. On average, the content of petroleum hydrocarbons in the La Perouse Strait does not exceed the limit of permissible concentration. Aniva Bay is slightly more polluted. The highest level of pollution in this area was noted near the port of Korsakov, once again confirming that the port is a source of intense pollution of the marine environment.
Pollution of the coastal zone of the sea along the northeastern part of Sakhalin Island is mainly associated with the exploration and production of oil and gas on the shelf of the island, and until the end of the 1980s, it did not exceed the maximum permissible concentration.
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The Sea of Okhotsk, whose resources are of great importance for states, is one of the most major seas related to the Pacific Ocean. Located off the coast of Asia. It is separated from the ocean by the islands - Hokkaido, the eastern coast of Sakhalin and the chain of the Kuril lands.
It is worth noting that this sea is considered the coldest of all located in the Far East. Even in summer, the temperature above it does not exceed 18 degrees C. south side, and in the northeast thermometers show 10 degrees - this is the maximum figure.
Brief description of the Sea of Okhotsk
It is cold and powerful. The Sea of Okhotsk washes the shores of Japan and Russia. According to its outlines, the reservoir resembles an ordinary trapezoid. The sea stretches from the southwest to the northeast. The length at the maximum limits is 2.463 km, and maximum width- 1,500 km. The coastline is over 10,000 km long. The depth of the Sea of Okhotsk (indicator of the maximum depression) is almost 4,000 km. The type of reservoir adjacent to the outskirts of the mainland is mixed.
Volcanic activity extends both to the surface and to the bottom of the sea. When a seismic movement or explosion occurs underwater underwater volcano, it can cause huge tsunami waves.
hydronym
The Sea of Okhotsk, whose resources are used in the national economic spheres of the two countries (Russia and Japan), got its name from the name of the Okhota River. By official sources earlier it was called Lamsky and Kamchatsky. In Japan, for a long time the sea was called "Northern". But due to confusion with another body of the same name, the hydronym was adapted and now the sea is called the Sea of Okhotsk.
Importance of the Sea of Okhotsk for Russia
It cannot be overestimated. Since 2014, the Sea of Okhotsk belongs to inland waters Russian Federation. The state makes full use of its resources. First of all, it is the main supplier of salmon fish species. These are chum salmon, sockeye salmon, chinook salmon and other members of the family. The extraction of caviar is organized here, which is highly valued. No wonder Russia is considered one of the largest suppliers of this product.
The problems of the Sea of Okhotsk, however, as well as other water bodies, have led to a significant decrease in populations. It was for this state that it was necessary to limit the catch of fish. And this applies not only to the salmon family, but also to other species, such as herring, flounder, cod.
Industry
Russia has achieved great results in the development of industry on the shores of the Sea of Okhotsk. First of all, these are ship repair enterprises and, of course, fish processing factories. These two areas were modernized in the 90s and are now of great importance for economic development states. Nowadays, many commercial enterprises have appeared here.
Industry is also developing quite well on about. Sakhalin. Earlier, in tsarist times, it was perceived negatively, as it served as a place for exile of people objectionable to the rule. Now the picture has changed radically. The industry is flourishing, people themselves tend to come here in order to earn big money.
Kamchatka seafood processing enterprises entered the world market. Their products are highly appreciated abroad. It meets the standards and is quite popular in many countries.
Thanks to oil and gas deposits, Russia is a monopoly in this area. There is not a single state that could supply the same volumes of oil and gas to Europe. That is why a lot of money from the sovereign treasury is invested in these enterprises.
Islands
There are few islands in the Sea of Okhotsk, the largest of them is Sakhalin. His coastline heterogeneous: in the northeast there is a lowland, the southeast is slightly elevated above sea level, in the west there is a shoal.
The Kuril Islands are of particular interest. They are small in size, there are about 30 large ones, but there are also smaller ones. Together they form a seismic belt - the largest on the planet. There are about 100 volcanoes on the Kuril Islands. Moreover, 30 of them are operational: they can constantly “excite” the Sea of Okhotsk.
The resources of the Shantar Islands are fur seals. The largest concentration of this species is observed here. However, recently their production has been regulated in order to avoid complete extermination.
gulfs
The coastline of the reservoir is slightly indented, although it has a large length. There are practically no bays and bays in this area. The basin of the Sea of Okhotsk is divided into three basins: the Kuril, TINRO and Deryugin basins.
The largest bays: Sakhalin, Tugursky, Shelikhov, etc. There are also several bays here - deeply cutting into the land sea bays that form the basin of large rivers. Among them are Penzhinskaya, Gizhiginskaya, Udskaya, Tauyskaya. Thanks to the bays, water exchange in the seas also occurs. And on this moment scientists call this question rather problematic.
Straits
They are part Okhotsk basin. This is the important element that connects the reservoir with and also with the Pacific Ocean. In addition, there are low and shallow and Nevelsk. They do not play a special role, since they are quite small. But the Krusenstern and Bussol straits are different large area, while their maximum depth reaches 500 meters. In many ways, they regulate the salinity of the Sea of Okhotsk.
Bottom and coastline
The depths of the Sea of Okhotsk are not uniform. From the side of Sakhalin and the mainland, the bottom is represented by a shoal - a continuation of the Asian part of the mainland. Its width is approximately 100 km. The rest of the bottom (about 70%) is represented by the continental slope. Near the Kuril Islands, next to about. Iturup is a sore cavity. In this place, the depth of the Sea of Okhotsk reaches 2,500 meters. At the bottom of the reservoir, two large towering sections of relief are distinguished with rather original names: the hill of the Institute of Oceanology and the USSR Academy of Sciences.
The coastline of the Sea of Okhotsk belongs to different geomorphological forms. Most of them are high and steep slopes. Only western territory Kamchatka and the east Sakhalin have a low-lying character. And here north coast is significantly indented.
Water exchange
The continental runoff is small. This is due to the fact that all the rivers flowing into the Sea of Okhotsk are not full-flowing, and cannot play a significant role. The most important is r. Cupid, it is on it that more than half of the total indicator of effluents falls. There are other relatively large rivers. This is Hunt, Uda, Bolshaya, Penzhina.
Hydrological characteristic
The reservoir is completely because the salinity of the Sea of Okhotsk is quite high. It is 32-34 ppm. It decreases closer to the coast, reaching a mark of 30 ‰, and in the intermediate layer - 34 ‰.
Most of the territory is covered in winter floating ice. Maximum low temperature water in the cold season ranges from -1 to +2 degrees. In summer, the sea depths warm up to 10-18ºC.
An interesting fact: at a depth of 100 meters there is an intermediate layer of water, the temperature of which does not change throughout the year and is 1.7 ° C below zero.
Climate features
The Sea of Okhotsk is located in temperate latitudes. This fact renders big influence on mainland, providing the Aleutian minimum dominates in the cold part of the year on the territory of the reservoir. It greatly influences northern winds, causing storm storms that continue throughout the winter.
In the warm season, weak southeasterly winds come from the mainland. Thanks to them, the air temperature rises to a large extent. However, cyclones come along with them, which can later form typhoons. The duration of such a typhoon can be from 5 to 8 days.
Sea of Okhotsk: resources
They will be discussed further. It is known that Natural resources Sea of Okhotsk is still poorly explored. The sea shelf with its hydrocarbon reserves is of the greatest value. Today, 7 are open on Sakhalin, Kamchatka, in the Khabarovsk Territory and Magadan administrative center. The development of these deposits began in the 70s. However, in addition to oil, the main wealth of the Sea of Okhotsk is flora and fauna. They are of great variety. Therefore, the industry is highly developed here. The most valuable species of salmon fish are found in the Sea of Okhotsk. In the depths, squids are mined, and in terms of catching crabs, the reservoir is in first place in the world. Recently, mining conditions have become more strict and harsh. And there are restrictions on the catch of some fish.
Fur seals, whales, seals live in the northern waters of the sea. Catching these representatives of the animal world is strictly prohibited. In recent years, fishing is gaining popularity - catching sea urchins and shellfish. From flora matter different types seaweed. Speaking about the use of the sea, it is worth noting its importance in transport sector. She is a priority. Important sea lines are laid here. trade routes, which connect big cities Korsakov (Sakhalin), Magadan, Okhotsk and others.
Ecological problems
The Sea of Okhotsk, like other waters of the World Ocean, suffers from human activities. Here are fixed ecological problems in the form of a drain of oil products and residues of gas compounds. Also quite problematic are the waste of industrial and household enterprises.
get dirty coastal zone began with the development of the first offshore fields, but until the end of the 80s it did not have such large-scale dimensions. Now human anthropogenic activity has reached a critical point and requires immediate resolution. The largest concentration of waste and pollution is concentrated off the coast of Sakhalin. This is mainly due to rich oil deposits.
The Sea of Okhotsk is one of the most large reservoirs on the entire planet. It is also one of the richest in terms of biological resources. The sea provides about 60% of the entire Russian Federation. Rare and endangered species live in its waters, and there are noisy "bird markets" on the banks.
The western boundary of the Sea of Okhotsk is drawn along east coast two islands: Sakhalin and Hokkaido. According to its physical and geographical characteristics, it is an inland sea. The Sea of Okhotsk also belongs to the seas of the so-called mixed continental-marginal type. Its area is 1603 thousand square meters. km. A average depth- 821 m. The maximum depth of the Sea of Okhotsk is 3916 m.
Straits of the Sea of Okhotsk
The Amur estuary, and also - these are the channels through which the Sea of \u200b\u200bOkhotsk connects with the Sea of \u200b\u200bJapan. Which ocean gives rise to the Sea of Japan? It, like the Okhotsk, belongs to the waters of the Pacific Ocean. With the help of a huge number of Kuril straits, the sea is also connected to the Pacific Ocean. The deepest are the straits of the Bussol and Krusenstern islands. According to the classification of geographer N. Zubov, the Sea of Okhotsk belongs to the category of basin seas. The depth of its straits is much less than the depth of the basin.
Islands of the Sea of Okhotsk
The part of which ocean the Sea of Okhotsk is, also determines its shape. In this part of the Pacific Ocean there are a large number of islands of various origins. But the coastline itself is considered relatively flat. The islands of the sea differ in their shape. There are also those that are located in the waters in compactly compressed groups. There are also singles. The map of the Sea of Okhotsk is dotted with many islands, including those that are in the zone of seismic activity (for example, these are the Kuriles). Scientists also distinguish the so-called islands of the transition zone. The first group includes those that are formed by a single lithospheric plate with the mainland.
And the second geographers include those that have the shape of elongated archipelagos. The first group includes small islands located near East Sakhalin. These are Seals and the Stone of Danger. Seal Island has a flat surface and steep banks. And the Danger Stone, in fact, is a group of bare stones located in the La Perouse Strait. Two hundred kilometers. from about. Sakhalin is located on Iona with rocky shores. Its height is about 150 m. And in the northwest is the Shantar archipelago, which includes about 15 islands, the territory of which is 2.5 km 2. IN Southern Kuriles included the islands of the so-called Great Kuril Ridge.
Salinity and temperature
The salinity of the waters is determined by the part of which ocean the Sea of Okhotsk is. The salinity of the sea is in many ways similar to the data of the Pacific Ocean. The surface waters of the Sea of Okhotsk have a salinity of 32.8-33.8 ppm. The intermediate layer has a salinity of 34.5 ppm. It is known that in the Pacific Ocean this figure is on average 30-35 ppm. The temperature at the surface of the water in the sea during the cold season ranges from -1.8°С to +2°С. In summer, the figures rise to + 18 ° С. But at a depth of about 50-150 meters, the water temperature remains constant year-round. It is about -1.7°C. Warmer waters with a temperature of about 2-3°C enter the sea through the Kuril Straits.
Sea ownership
Since March 2003, Russia has been recognized as the official right to the enclave of the sea. The Sea of Okhotsk, or rather, a significant part of its shelf with an area of \u200b\u200babout 52 thousand square meters. km. is now in the possession of the Russian Federation. This event was especially important for local fishermen. After all, before they could not do fishing anywhere in the sea. After the transfer of the Sea of Okhotsk to Russia, they will no longer have competitors from other countries who previously had to give away part of the fish they caught. In addition, other workers in the industrial industry since then have been able to cross the sea area along the most convenient route.
Biodiversity
"The Sea of Okhotsk - the basin of which ocean?" - this question is also often asked in connection with the description of its marine wealth. The fauna of the sea is rich in species that came to these waters from the Pacific territories. There are crabs, shrimps, sea urchins and stars, seals, whales, fur seals. According to some estimates, it ranks first in the world in terms of the number of crabs. It is in the waters of the Sea of \u200b\u200bOkhotsk that the giant king crab lives, the leg span of which can reach 1.5 m.
About 200 species of fish are also found in the sea - these are herring, cod, navaga, pollock, capelin. Also in this area you can often meet sharks. Their species composition is similar Bering Sea: katran, polar and salmon sharks are found here.
Other riches
The Sea of Okhotsk is rich not only in fish stocks, crabs and various shellfish. Geologists say that about 40% of the territory of its shelf are sources of black gold - oil. There are also rich deposits of natural gas. Many experts tend to believe that the amount of oil deposits at the bottom of the sea exceeds three billion barrels. But the complete transfer of the sea to Russia also means some obligations for Russia. The state must protect against poachers who hunt illegally on the territory of the sea.
Bottom Features
The bottom of the sea is very diverse. There are depressions, and gutters, and many hills. The part of which ocean the Sea of Okhotsk is, also determines the nature of its shelf. According to its characteristics, it is related to the bottom of the Pacific Ocean. The Pacific Ocean is known to have the largest number of deep sea trenches on the planet. The Sea of Okhotsk is located in the transition zone between the Asian continent and the Pacific Ocean. The sea region is a huge lithospheric plate, which is located between the Eurasian, North American and Pacific plates. The Pacific Ocean on the world map is separated from the Sea of Okhotsk by the Kuril-Kamchatka deep-sea trench.
Winter temperature surface water the sea usually does not fall below freezing temperature (at salinity values of 31-33.5‰, this is -1.6- -1.8°C). In summer, the temperature of surface waters usually does not exceed 7-14°C. Its values in different areas of the sea both in summer and winter are determined as depth of place, as well as horizontal and vertical movements of water. In coastal shallow areas of the sea and in areas of warm currents, the water temperature is higher than in areas of strong tidal mixing, where relatively warm surface and cold subsurface waters mix, or along the coast of Sakhalin, where the cold East Sakhalin Current passes.
The southern part of the sea is under the influence of warm currents, and the surface water temperature along the Kuril Islands is higher than along the continent. However, in February-March the inflow warm waters Soya weakens with the current (the La Perouse Strait is clogged with ice transferred from the north), and the temperature of the warm waters of the East Kamchatka Current invading the sea drops to 1 ° -2 ° С. But even so, the temperature of the surface waters of the southeastern part of the sea is several degrees higher than the temperature of the waters of the rest of the sea by 1-2°C.
Spring warming (from April-May) of surface waters everywhere leads to an increase in temperature and the disappearance of ice. The areas of the shelf and the southern part of the sea are the most heated (up to 2 and 6°С, respectively).
The rearrangement of the temperature field to the summer state is most noticeable in June. The areas of strong tidal mixing (for example, the entrance to Shelikhov Bay) remain the least heated.
The highest values (about 14°C on average) of the temperature of the surface waters of the sea were recorded in August. The water temperature is higher in areas of warm currents (for example, off the coast of Hokkaido) and near the coast (except for the coast of Sakhalin Island, where upwelling is observed) and lower in areas of tidal mixing. Due to the influence of warm and cold currents, the water temperature in the western (cold) and eastern (relatively warm) parts of the sea usually differ by several degrees.
The cooling of the surface waters of the sea begins in September. In October, the most noticeable decrease in temperature to 4°C in the northwestern part of the sea is due to the rise of deep waters. However, in most of the sea the temperature is still quite high (5.5 to 7.5°C). In November, there is a sharp decrease in surface water temperature. North of 54°N the water temperature drops below 2°C.
The distribution of surface water temperature in December remains with slight changes until spring. The lowest water temperatures correspond to areas of polynyas, and high - districts inflow of warm waters (La Perouse Strait and south- East End sea) and rising waters (Kashevarov Bank).
The distribution of water temperature on the surface makes it possible to distinguish thermal fronts (Fig.).
Main thermal fronts of the Sea of Okhotsk
Fronts form during the absence of ice and are most developed at the end of summer.
The thermal fronts of the sea have a different origin: tidal mixing, at the boundaries of warm currents, river runoff (especially from the Amur Estuary) and zones of subsurface water rise. Fronts appear at the boundary of warm currents near west coast Kamchatka (warm current from the Pacific Ocean) and along Hokkaido (warm current from the Sea of Japan). Fronts also form at the boundaries of strong tide zones (Shelikhov Bay and the area of the Shantar Islands). The East Sakhalin coastal front is caused by the rise of cold subsurface waters during the southern winds of the summer monsoon. The front in the central part of the sea corresponds to the average line of the distribution of packed ice in winter. Throughout the summer, there is a zone of cold (less than 3°C) water in the area of the Kashevarov Bank.
In the western part of the deep-sea basin, an anticyclonic eddy is observed throughout the year. The reason for its existence is the invading jets of warm water of the Soya Current and denser cold waters of the East Sakhalin Current. In winter, due to the weakening of the Soya current, the anticyclonic eddy weakens.
Water temperature distribution on the 50 m horizon
At the 50 m level, the water temperature is usually close (in winter) or lower (in summer) to the surface temperature. In winter, the horizontal distribution of water temperature in areas of ice formation due to intensive mixing of water up to a horizon of 50 m (and on the shelf to a depth of 100 m) is similar to the surface one. Only in May in most areas of the sea, except for zones of strong tidal mixing, does the surface layer warm up and, thus, a cold subsurface layer appears deeper than it. In July, at a horizon of 50 m, water with a temperature of less than 0°C is observed only in the northwestern part of the sea. In September, the water temperature continues to rise. But, if in the Shelikhov Bay it is about 3°C, near the Kuril Islands 4°C, then in most of the sea it is about 0°C.
The maximum values of water temperature at the horizon of 50 m are usually observed in October. But already in November, the area of water with a temperature of less than 1°C sharply increases.
The features of the water temperature field are:
Two tongues of relatively warm (over 0°C) waters along the Kamchatka peninsula and from the 4th Kuril Strait to Iona Island;
Warm water zone in the southwestern part of the sea. In winter, it narrows to a narrow strip along about. Hokkaido, and in summer it occupies most of the deep-water basin.
Distribution of water temperature on the horizon of 100 m
At the 100 m horizon, water of the cold subsurface layer is usually noted. Therefore, the lowest water temperatures are typical for the coastal regions of the northwestern part of the sea, and the highest for the zone along the Kuril Islands and for the strip from the 4th Kuril Strait to the Kashevarov Bank.
Intra-annual changes in water temperature are similar to those noted for the 50 m horizon.
Distribution of water temperature on the horizon of 200 m
A feature of this horizon is a sharp decrease in seasonal changes. But they (winter decrease and summer increase in water temperature) are always there. The cold subsurface layer on this and underlying horizons can be identified only in areas of intense tidal mixing (in particular, in the Kuril Straits and the adjoining part of the sea). The distribution of warm water, as well as at higher horizons, can be traced in two branches - along Kamchatka and from the 4th Kuril Strait to Iona Island.
Distribution of water temperature on the horizon of 500 m
At the horizon of 500 m and deeper, there are no seasonal changes. On this horizon mean annual temperature higher than on the sea surface. Below this horizon, the water temperature continuously decreases.
Distribution of water temperature on the horizon of 1000 m
The maximum water temperature at a horizon of 1000 m is located near the Krusenstern Strait (2.44°C), through which, apparently, the greatest transfer of warm water to the Sea of Okhotsk occurs at this depth. The lowest water temperatures on this horizon (2.2°С) are observed not in the northern part of the sea, but in the southern part.
The water temperature fields at standard horizons are given below.
1. Sea of Okhotsk.
2. The sea enters the Pacific basin.
3. Located in the northwestern part of the Pacific Ocean, separated from the ocean by the Kamchatka Peninsula, the Kuril Islands and the island of Hokkaido.
4. Located between 43° and 62° parallel north latitude.
5. Position of the sea between 135° and 165° meridians east longitude.
6. The length of the sea in directions in degrees and kilometers:
The extent of the sea from south to north is 19° degrees, i.e. approximately 2100 km;
The length of the sea from east to west is 20° degrees, 1575 km.
The length in km was calculated based on the length between parallels and meridians on a map with a scale of 1:35,000,000.
7. Washes the shores of Russia and Japan: the Kamchatka Peninsula, the Kuril Islands, about. Hokkaido, oh Sakhalin, Shantar Islands.
8. neighboring seas: the La Perouse Strait and the Tatar Strait (through the Amur Estuary) connect the Sea of Okhotsk with the Sea of Japan.
Neighbor Ocean: The First Kuril Strait and a number of straits in the chain of the Kuril Islands, such as the Fourth Kuril Strait, the Krusenstern Strait, the Bussol Strait and the Friza Strait, connect the Sea of Okhotsk to the Pacific Ocean.
9. View of the sea: marginal sea.
10. In winter, the water temperature at the sea surface ranges from -1.8° to 2.0° C, in summer surface waters warm up to 10° C and above.
11. Max Depth sea: 3521 m (in the Kuril basin), in some sources there is a depth of 3916 m, but I did not find this figure on the map, so you can operate with it if it is in your textbook.
Fig. 12. Distribution of depths The shelf zone (0–200 m) occupies about 20% of the sea area, the continental slope (200–2000 m), on which separate underwater heights, depressions and islands are distinguished by a sharp change in depths, and the deep-sea basin occupies about 65%, and the deepest basin (more than 2500 m), located in the southern part of the sea - 8% of the sea area.
13. Distribution of water salinity: according to the map of the average annual salinity of the surface waters of the World Ocean, in the northern and eastern parts of the sea, the salinity of surface waters is up to 32 ppm, and in the central, western and southern parts sea surface water salinity up to 33 ppm.
14. The Sea of Okhotsk is located in a temperate climate zone, while its eastern part (in the region of the Kuril Islands) is located in maritime area temperate climate, and the rest in the temperate monsoon region.
15. Features of the structure of the bottom:
The bottom is a wide range of different underwater elevations, depressions and trenches. The northern part of the sea is located on the continental shelf. In the western part of the sea there is a sandbank of Sakhalin, located near the island. In the east of the sea is the continental shelf of Kamchatka. As stated in paragraph 12, most of expanses of water is located on the continental slope. South edge sea is the deepest zone, this part of the sea is a bed that is located along the Kuril Islands. The southwestern part of the sea is characterized deep depressions and slopes. In the central zone of the sea there are two elevations: the Academy of Sciences and the Institute of Oceanology, they divide the marine underwater space into 3 basins: the northeastern TINRO basin (small depth of about 850 m, flat terrain), which is located west of Kamchatka. The second basin is the Deryugin depression, located east of Sakhalin, the water depth here reaches 1700 m, the bottom is a plain, the edges of which are somewhat elevated. The third basin - the Kuril - is the deepest (about 3300 m) of these three.
16. Features of the organic world.
Flora and fauna, on the one hand, are distinguished by great diversity, and, on the other hand, by the uneven distribution of this diversity. If in the southern, warmer part, the number of fish species is about 300, then in the northern, colder part, the number of species is more than two times less, only about 123 species. Nevertheless, in terms of stocks of commercial crab, the sea ranks first in the world. Salmon fish are of great value: chum salmon, pink salmon, coho salmon, chinook, sockeye salmon as a source of red caviar. There is also intensive fishing for herring, pollock, flounder, cod, navaga, capelin, etc. Whales, seals, sea lions, fur seals live in the sea. A huge amount of green, brown and red medicinal algae stands out from the flora.
