Sea of Okhotsk located in the northwestern part of the 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 limited by the coast of the island of Hokkaido, the eastern coast of the island of Sakhalin and the coast of the Asian continent. The sea extends significantly from southwest to northeast within a spherical trapezoid with coordinates 43°43"–62°42" N. w. and 135°10"–164°45" E. d. The greatest length of the water area in this direction is 2463 km, and the width reaches 1,500 km. The surface area of the sea surface is 1,603 thousand km2, the length of the coastline is 10,460 km, and the total volume of sea water is 1,316 thousand km3. In my own way geographical location it belongs to the marginal seas of the mixed continental-marginal type. The Sea of Okhotsk is connected to the Pacific Ocean by numerous straits of the Kuril Island chain, and to the Sea of Japan - through the La Perouse Strait and through the Amur Estuary - by the Nevelsky and Tatar Straits. The average sea depth is 821 m, and the greatest is 3521 m (in the Kuril Basin).
The main morphological zones in the bottom topography are: the shelf (the mainland and island shoals of Sakhalin Island), the continental slope, on which individual underwater hills, depressions and islands are distinguished, and the deep-sea basin. The shelf zone (0–200 m) has a width of 180–250 km and occupies about 20% of the sea area. The wide and gentle continental slope (200–2000 m) in the central part of the basin 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 hills and depressions are distinguished, where the depths change sharply (the rise of the Academy of Sciences, the rise of the Institute of Oceanology and the Deryugin Basin). The bottom of the deep-sea Kuril Basin is a flat abyssal plain, and the Kuril ridge is a natural threshold that fences off the sea basin from the ocean.
The Sea of Okhotsk is connected to the Sea of Japan through the Amur Estuary, Nevelskogo in the north and La Perouse in the south, and the numerous Kuril Straits are connected to the Pacific Ocean. The chain of the Kuril Islands is separated from the island of Hokkaido by the Izmena Strait, and from the Kamchatka Peninsula by the First Kuril Strait. The straits connecting the Sea of Okhotsk with adjacent areas of the Sea of Japan and the Pacific Ocean provide the possibility of water exchange between basins, which, in turn, have a significant impact on the distribution of 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 island chain, which stretches for about 1200 km, on the contrary, are deeper, and their total width is 500 km. The deepest waters are the Bussol (2318 m) and Kruzenshtern (1920 m) straits.
The northwestern coast of the Sea of Okhotsk is practically devoid of large bays, while the northern coast is significantly indented. The Taui Bay juts into it, the shores of which are indented by 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 bays. The Gizhiginskaya and Penzhinskaya bays are separated by the elevated Taygonos Peninsula. In the southwestern part of Shelikhov Bay, north of the Pyagina 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 their outline and form small bays. On the Sea of Okhotsk side, the largest bays are located near the island of Iturup, which are deep and have a very complexly dissected bottom.
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 km3 per year, with about 65% of the flow coming from the Amur River. Other relatively large rivers - Penzhina, Okhota, Uda, Bolshaya (in Kamchatka) - bring significantly 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 mouths of large rivers.
Shores The Sea of Okhotsk in different areas belongs to different geomorphological types. For the most part, these are abrasive shores modified by the sea, and only on the Kamchatka Peninsula and Sakhalin Island 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 are somewhat elevated.
According to the characteristics of composition and distribution bottom sediments Three main zones can be distinguished: the central zone, which is composed predominantly of diatomaceous silt, silty-clayey and partially clayey silts; zone of distribution of hemipelagic and pelagic clays in the western, eastern and northern parts of the Sea of Okhotsk; as well as a zone of distribution of heterogeneous sands, sandstones, gravels 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 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.
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. 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 the central regions - –10…–15°С, and in the south-eastern part of the sea - –5 ...–6°С.
In autumn-winter, cyclones are predominantly of continental origin. 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 destroyed, and the Hawaiian maximum intensifies. 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 the same 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 to the northeast (from 18°C to 10–10.5°C).
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.
Geographical location, large length along the meridian, 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 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 upper layers The southern part of the Kuril ridge is dominated by the flow of Sea of Okhotsk waters, and in the upper layers of the northern part of the ridge there is an influx of Pacific waters. In the deep layers, the influx of Pacific waters predominates.
The influx of Pacific waters significantly affects the distribution of temperature, salinity, 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 that has spring, summer and autumn modifications. It is a thin heated layer 15–30 m thick, which limits the upper maximum of stability, mainly determined by temperature;
– 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‰) and varying temperatures;
– the intermediate water mass is formed mainly due to the descent of water along underwater slopes, within the sea, located from 100–150 to 400–700 m, and is characterized by a temperature of 1.5 ° C and a salinity of 33.7‰. This body of water 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 horizons below 800–1000 m. This water mass is located at 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 deep water of the northwestern part of the Pacific Ocean near the 2300 m horizon. This water mass fills the basin from the 1350 m horizon to the bottom and is characterized by a temperature of 1.85 ° C and a salinity of 34.7‰, which change only slightly with depth.
Water temperature on the surface of the sea it decreases from south to north. In winter, almost everywhere the surface layers are cooled to a freezing temperature of –1.5...–1.8°C. Only in the southeastern part of the sea does it remain 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 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 warmest waters (up to 18–19°C) are those adjacent to the island of Hokkaido. In the central regions of the sea, the water temperature is 11–12°C. The coldest surface waters are observed off the island of Jonah, off Cape Pyagin and near the Krusenstern Strait. In these areas, the water temperature is between 6–7°C. 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°С on the surface to –0.25°С at horizons of 500– 600 m, deeper it rises to 1–0°С, in the southern part of the sea and near the Kuril Straits the water temperature from 2.5–3°С on the surface decreases to 1–1.4°С at horizons of 300–400 m and further gradually increases to 1.9–2.4°C in the bottom layer.
In summer, surface waters are heated to a temperature of 10–12°C. In the subsurface layers, the water temperature is slightly lower than on the surface. A sharp drop 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 horizons of 200–250 m is equal to 1.5–2°С. 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°С on the surface drops to 3–8°С at a horizon of 25 m, then to 1.6–2.4°С at a horizon of 100 m and up to 1.4–2°С 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 is it 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 changes 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, the surface salinity 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‰ and then 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 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 time 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 near the coast.
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.
Under the influence of winds and the influx of water through the Kuril Straits, the characteristic features of a system of non-periodic currents Sea of Okhotsk. 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.
Strong currents move around the sea along the coastline counterclockwise: the warm Kamchatka Current, the stable East Sakhalin Current and the rather strong Soya Current.
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.
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 Bay (30–45 cm/s), in the area of the Kuril Straits (15–40 cm/s), over the Kuril Basin (11 –20 cm/s) and during the Soya River (up to 50–90 cm/s).
In the Sea of Okhotsk are well expressed different kinds periodic tidal currents: semi-diurnal, diurnal and mixed with a predominance of semi-diurnal or diurnal components. Tidal current velocities 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.
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 some areas in the 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 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 normal 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, thanks to the winds, significant masses of ice are carried into it from the north, often accumulating near the Kuril Islands.
Ice cover in the Sea of Okhotsk lasts for 6–7 months. Floating ice covers more than 75% of the sea surface. 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. Some of the ice from the Sea of Okhotsk is carried into the ocean, where it almost immediately collapses and melts.
Forecast resources hydrocarbons The Sea of Okhotsk is estimated at 6.56 billion tons of oil equivalent, proven reserves are over 4 billion tons. The largest fields are on the shelves (along the coast of Sakhalin Island, the Kamchatka Peninsula, Khabarovsk Territory and the Magadan Region). The deposits of Sakhalin Island are the most studied. Exploration work on the island's shelf began in the 70s. XX century, by the end of the 90s, 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. Total gas reserves on the Sakhalin shelf are estimated at 3.5 trillion m3.
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Vegetation and fauna are very diverse. The sea ranks first in the world in terms of commercial crab reserves. Salmon fish are of great value: chum salmon, pink salmon, coho salmon, chinook salmon, sockeye salmon - a source of red caviar. Intensive fishing is carried out for herring, pollock, flounder, cod, navaga, capelin, etc. The sea is inhabited by whales, seals, sea lions, and fur seals. Fishing for mollusks and sea urchins is becoming increasingly interesting. Various algae are ubiquitous in the littoral zone.
Due to the poor development of the surrounding 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 Tauyskaya Bay in the northern part of the sea and the shelf areas of Sakhalin Island are exposed. About 23 tons of petroleum products enter the northern part of the sea annually, with 70–80% coming from river runoff. Pollutants enter Tauyskaya Bay from coastal industrial and municipal facilities, and Magadan wastewater 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 wastewater from municipal facilities. The annual supply of petroleum products to the southwestern part of the sea is estimated at approximately 1.1 thousand tons, with 75–85% from river runoff.
Petrocarbons enter the Sakhalin Bay mainly with the runoff of the Amur River, so their maximum concentrations are usually observed in the central and western parts of the bay along the axis of the incoming Amur waters.
The eastern part of the sea - the shelf of the Kamchatka Peninsula - is polluted by river runoff, with which the bulk of petroleum carbons enter the marine environment. Due to the reduction in work at the fish canning enterprises of the peninsula since 1991, there has been a decrease in the volume 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 the 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 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 Aniva Bay - are subject to intense oil pollution in the spring and summer by commercial and fishing fleets. On average, the content of petroleum carbons in the La Perouse Strait does not exceed the permissible concentration limit. Aniva Bay is slightly more polluted. The highest level of pollution in this area was observed 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 north-eastern 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 80s of the last century did not exceed the maximum permissible concentration.
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Square Sea of Okhotsk 1.603 million sq. km. Average depth 1780 m maximum depth 3521 m. West Side 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 coastline 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 part 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. 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 western part of the sea is located on the continental shelf and has 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. 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, and Kekurny. In the east, the coastline of the Kamchatka Peninsula is practically devoid of bays. In the southwest, the largest are Aniva and Terpeniya bays, Odessa Bay on the island of Iturup.
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 conditional lines 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 and small island Iona is the only one of all that is remote from the shores. 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 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% total area seas. 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 maximum depth 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 have a very complex nature. 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%. At strong excitement 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. With the same character 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 warming of waters in open areas and desalination near 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 motionless ice - fast ice, and floating ice, representing 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 surface by northwest winds. Kuril Islands and clog 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 Sea of Okhotsk is one of the largest bodies of water 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. Its waters are home to rare and endangered species, and its banks are home to bustling bird colonies.
The western border of the Sea of Okhotsk is drawn along the eastern shore of 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-margin type. Its area is 1603 thousand square meters. km. And the average depth is 821 m. The maximum depth of the Sea of Okhotsk is 3916 m.
Straits of the Sea of Okhotsk
The Amur Estuary, as well as those canals through which the Sea of Okhotsk is connected to the Sea of Japan. Which ocean gives rise to the Sea of Japan? It, like 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. In accordance with 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
Which ocean the Sea of Okhotsk is part of determines its outline. 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 located in the waters in compactly compressed groups. There are also loners. The map of the Sea of Okhotsk is dotted with many islands, including those that are located in a zone of seismic activity (for example, the Kuril Islands). Scientists also identify the so-called islands of the transition zone. The first group includes those formed by a single lithospheric plate with the continent.
And to the second, geographers include those that have the shape of elongated archipelagos. The first group includes small islands located near Eastern Sakhalin. This is the Seal and the Danger Stone. Seal Island has a flat surface and steep banks. And the Danger Stone is essentially a group of bare rocks located in the La Perouse Strait. Two hundred km. from Fr. Sakhalin is located on. Iona with rocky shores. Its height is about 150 m. And in the north-west is the Shantar archipelago, which includes about 15 islands, the territory of which is 2.5 km 2. The Southern Kuril Islands include the islands of the so-called Great Kuril Ridge.
Salinity and temperature
The salinity of the waters is determined by which ocean the Sea of Okhotsk is part of. The salinity indicators of the sea are in many ways similar to those 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 averages 30-35 ppm. The temperature at the surface of the sea water in the cold season ranges from -1.8°C to +2°C. In summer, the readings rise to +18°C. But at a depth of about 50-150 meters, the water temperature remains constant all year round. It is about -1.7°C. Through the Kuril Straits, warmer waters with a temperature of about 2-3°C enter the sea.
Belonging to the sea
Since March 2003, Russia has been recognized as the official right to the sea enclave. The Sea of Okhotsk, or more precisely, a significant part of its shelf with an area of about 52 thousand square meters. km. is now at the disposal of the Russian Federation. This event was especially important for local fishermen. After all, before they could not fish anywhere in the sea. After the transfer of the Sea of Okhotsk to Russia, they will no longer have competitors from other countries, which previously had to give away part of the fish they caught. In addition, other industrial workers have since had the opportunity to cross the maritime territory along the most convenient route.
Biological diversity
“The Sea of Okhotsk is the basin of which ocean?” - this question is also often asked in connection with the description of its marine riches. Animal world The sea is rich in species that came to these waters from the Pacific territories. Crabs, shrimps live here, 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 Okhotsk that the giant Kamchatka crab lives, whose leg span can reach 1.5 m.
There are also about 200 species of fish in the sea - herring, cod, navaga, pollock, and capelin. Sharks can also often be seen in this area. Their species composition is similar to the Bering Sea: katran, polar and salmon sharks are found here.
Other wealth
The Sea of Okhotsk is rich not only in fish stocks, crabs and various shellfish. Geologists claim that about 40% of its shelf area is a source of black gold - oil. There are also rich natural gas deposits here. Many experts are inclined to believe that the number 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 illegally fishing in the sea.
Bottom Features
The seabed is very diverse. There are depressions, troughs, and many hills. The type of ocean the Sea of Okhotsk is part of 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 contain 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 that lies between the Eurasian, North American and Pacific plates. Pacific Ocean on the world map it is separated from the Sea of Okhotsk by the Kuril-Kamchatka deep-sea trench.
