Sea of ​​Okhotsk major ports. Physical and geographical conditions of the Sea of ​​Okhotsk

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

Sea of ​​Okhotsk map Far East

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

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

There are few islands in the Sea of ​​Okhotsk. The largest border island is Sakhalin. The Kuril ridge has about 30 large, many small islands and rocks. The Kuril Islands are located in the seismic activity belt, which includes more than 30 active and 70 extinct volcanoes. Seismic activity is manifested on the islands and under water. In the latter case, tsunami waves are formed. In addition to the named "marginal" islands in the sea, there are the islands of Shantarsky, Spafaryeva, Zavyalova, Yamsky and the small island of Iona - the only one of them remote from the coast.
With a large length, the coastline is indented relatively weakly. At the same time, it forms several large bays (Aniva, Patience, Sakhalin, Academies, Tugursky, Ayan, Shelikhov) and bays (Udskaya, Tauiskaya, Gizhiginskaya and Penzhinskaya).

Atsonopuri volcano, Iturup island, Kuril Islands

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

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

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

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

Extraction of hydrocarbon raw materials on the shelf of Sakhalin.

The rivers Amur, Okhota, Kukhtui flow into it.

Sea of ​​Okhotsk Cape Velikan, Sakhalin Island

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

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

Cape Medyay Sea of ​​Okhotsk

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

On November 13-14, 2013, the Subcommittee established within the framework of the UN Commission on the Limits of the Continental Shelf agreed with the arguments of the Russian delegation as part of the consideration of the application of the Russian Federation for recognition of the bottom of the above-mentioned area high seas extension of the Russian continental shelf. On March 15, 2014, the 33rd session of the Commission in 2014 adopted a positive decision on the Russian application, first filed in 2001, and filed in a new edition in early 2013, and the central part of the Sea of ​​Okhotsk outside the exclusive economic zone of the Russian Federation was recognized Russian continental shelf.
Consequently, in the central part, other states are prohibited from extracting "sedentary" biological resources (for example, crab) and developing subsoil. Catching other biological resources, such as fish, is not subject to the restrictions of the continental shelf. Consideration of the application on the merits became possible due to the position of Japan, which, by an official note dated May 23, 2013, confirmed its consent for the Commission to consider the essence of the application without regard to resolving the issue of the Kuril Islands. Sea of ​​Okhotsk

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

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

From December 30, 2010 to January 31, 2011, a rescue operation was carried out in the Sea of ​​Okhotsk, which received extensive media coverage.
The operation itself was large-scale, according to the Deputy Minister of Transport Viktor Olersky and the head of the Federal Agency for Fishery Andrei Krayny, rescue operations on such a scale have not been carried out in Russia for 40 years.
The cost of the operation was in the range of 150-250 million rubles, 6,600 tons of diesel fuel were spent on it.
15 ships, on which there were about 700 people, were captured by ice.
The operation was carried out by the forces of the icebreaking flotilla: the icebreakers Admiral Makarov and Krasin, the icebreaker Magadan and the tanker Victoria worked as auxiliary vessels. The coordinating headquarters of the rescue operation was located in Yuzhno-Sakhalinsk, the work was carried out under the leadership of the Deputy Minister of Transport of the Russian Federation Viktor Olersky.

Most of the vessels got out on their own, the icebreakers rescued four vessels: the trawler Cape Elizabeth, the research vessel Professor Kizevetter (first half of January, Admiral Makarov), the refrigerator Coast of Hope and the mother ship Sodruzhestvo.
The first aid was provided to the seiner Cape Elizabeth, whose captain led his vessel after the introduction of a ban on entering the area.
As a result, Cape Elizabeth was frozen into ice in the area of ​​the Sakhalin Bay. Sea of ​​Okhotsk

The second liberated vessel was the Professor Kizevetter, whose captain, as a result of the investigation, was deprived of his diploma for six months.
In the area of ​​January 14, the icebreakers gathered together the remaining ships in distress, after which the icebreakers escorted both vessels of the caravan on a coupler.
After the “whiskers” of the “Commonwealth” broke off, it was decided to first drive a refrigerator through heavy ice.
The wiring was suspended in the region on January 20 due to weather conditions, but on January 24, the Coast of Hope refrigerator was brought to clean water.
On January 25, after bunkering, the Admiral Makarov returned to escort the mother ship.
On January 26, the towing "whiskers" broke again, we had to lose time for the delivery of new ones by helicopter.
On January 31, the floating base Sodruzhestvo was also taken out of ice captivity, the operation ended at 11:00 Vladivostok time.

Red Cape, Three Brothers Islands

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

Sakhalin Bay, swans have arrived Sea of ​​Okhotsk

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

Aniva Bay, Korsakov Port, Sakhalin Island

ANIVA BAY
Aniva is a bay of the Sea of ​​Okhotsk south coast Sakhalin Islands, between the peninsulas of Crillon and Tonino-Anivsky. From the south it is wide open to the La Perouse Strait.
The origin of the name of the bay is most likely connected with the Ainu words "an" and "willow". The first is usually translated as "available, located", and the second - as " mountain range, rock, top"; thus, "Aniva" can be translated as "having ridges" or "located among the ridges (mountains)".
Width 104 km, length 90 km, maximum depth 93 meters. The narrowed part of the bay is known as Salmon Bay. The warm current Soya affects the temperature regime and the dynamics of currents inside the bay, which is changeable.

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

The island got its name from the Manchu name of the Amur River - "Sakhalyan-ulla", which means "Black River" - this name, printed on the map, was erroneously attributed to Sakhalin, and in further editions of the maps it was already printed as the name of the island.

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

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

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

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

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

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

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

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

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

Geological structure
The Kuril Islands are a typical ensimatic island arc at the edge of the Okhotsk plate. It sits above a subduction zone where the Pacific Plate is being swallowed up. Most of the islands are mountainous. The highest height is 2339 m - Atlasov Island, Alaid volcano. The Kuril Islands are located in the Pacific volcanic ring of fire in a zone of high seismic activity: out of 68 volcanoes, 36 are active, there are hot mineral springs. Large tsunamis are not uncommon. The most famous are the tsunami of November 5, 1952 in Paramushir and the Shikotan tsunami of October 5, 1994. The last major tsunami occurred on November 15, 2006 in Simushir.

DETAILED GEOGRAPHY OF THE SEA OF OKHOTSK, DESCRIPTION OF THE SEA
Basic physical and geographical features.
Very importance have straits connecting the Sea of ​​Okhotsk with the Pacific Ocean and the Sea of ​​Japan, and their depths, since they determine the possibility of water exchange. The Nevelskoy and La Perouse straits are comparatively 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 somewhat larger - about 40 km, and the greatest depth is 53 m.

At the same time, the total width of the Kuril Straits is about 500 km, and the maximum depth of the deepest of them (Bussol Strait) exceeds 2300 m. Thus, the possibility of water exchange between the Sea of ​​Japan and the Sea of ​​Okhotsk is incomparably less than between the Sea of ​​Okhotsk and the Pacific Ocean. However, even the depth of the deepest of the Kuril Straits is much less than the maximum depth of the sea, therefore, r, which separates the sea basin from the ocean.
The most important for water exchange with the ocean are the straits of Bussol and Krusenstern, 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. The Friza, Fourth Kuril, Rikord and Nadezhda straits are of less importance, the depths of which are more than 500 m. The depths of the remaining straits generally do not exceed 200 m, and the areas are insignificant.

The shores of the Sea of ​​Okhotsk, which are not identical in external forms and structure, in different regions belong to different geomorphological types. From fig. 38 shows that for the most part these are abrasion shores altered by the sea, only in the west of Kamchatka and in the east of Sakhalin there are accumulative shores. In general, the sea is surrounded by high and steep shores. In the north and northwest, rocky ledges descend directly to the sea. A less high, and then a low-lying mainland coast approaches the sea near the Sakhalin Bay. The southeastern coast of Sakhalin is low, and the northeastern coast is low. very abrupt. The northeastern coast of Hokkaido is predominantly low-lying. The coast of the southern part of western Kamchatka has the same character, but its northern part is distinguished by some elevation of the coast.

The bottom relief of the Sea of ​​Okhotsk is varied and uneven. In general, it is characterized by the following main features. The northern part of the sea is a continental shelf - an underwater continuation of the Asian mainland. The width of the continental shoal in the area of ​​the Ayano-Okhotsk coast is approximately 100 miles, in the area of ​​the Uda Bay - 140 miles. Between the meridians of Okhotsk and Magadan, its width increases to 200 miles. From the western edge of the basin of the sea is the island sandbar of Sakhalin, from the eastern edge - the continental shelf 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 separate underwater heights, depressions and trenches stand out.
The deepest southern part of the sea deeper than 2500 m, which is a section of the bed, occupies 8% total area. It is elongated as a strip along the Kuril Islands, gradually narrowing from 200 km against about. Iturup up to 80 km against the Krusenstern Strait. Great depths and significant slopes of the bottom distinguish southwestern part sea ​​from the northeast, lying on the continental shelf.
Of the large elements of the relief of the bottom of the central part of the sea, two underwater hills stand out - the Academy of Sciences of the USSR and the Institute of Oceanology. Together with the protrusion of the continental slope, they determine the division of the sea basin into three basins: the northeastern TINRO basin, the northwestern Deryugin basin, and the southern deep-water Kuril basin. The depressions are connected by gutters: Makarov, P. Schmidt and Lebed. To the northeast of the TINRO depression, the Shelikhov Bay trough extends.

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

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

The hill of the Institute of Oceanology has a rounded shape, it is extended in the latitudinal direction by almost 200 miles, and in the meridional direction by about 130 miles. The minimum depth above it is about 900 m. The upland of the USSR Academy of Sciences is indented by the peaks of underwater valleys. A remarkable feature of the relief of the hills is the presence of their flat tops, which occupy a large area.

CLIMATE OF THE SEA OF Okhotsk
By its location, the Sea of ​​Okhotsk is located in the monsoon climate zone of temperate latitudes, which is significantly influenced by the physical and geographical features of the sea. Thus, a significant part of it in the west 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 in the west, and not in the north. 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 effect of cooling factors is stronger than warming factors, so the Sea of ​​Okhotsk is generally the coldest of the Far Eastern seas. At the same time, its large meridional extent causes significant spatial differences in the synoptic situation and meteorological indicators in each season. 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. Such a distribution of large-scale baric systems determines the dominance of strong, stable northwestern and northern winds, often reaching storm strength. Low winds and calms 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 northwest of the sea is −20–25°, in the central regions −10–15°, only in the southeastern part of the sea it is −5–6°, which is explained by the warming effect Pacific Ocean.

The autumn-winter time is characterized by the emergence of cyclones of predominantly continental origin. They entail intensification, winds, and sometimes a decrease in air temperature, but the weather remains clear and dry, as they bring in continental air from the chilled mainland of Asia. In March-April, large-scale baric fields are restructured. The Siberian anticyclone is collapsing and the Honolulu High is getting stronger. As a result, during the warm season (May to October), the Sea of ​​Okhotsk is under the influence of the Honolulu High and the area of ​​low pressure located over Eastern Siberia. In accordance with this distribution of the centers of action of the atmosphere, weak southeasterly winds prevail over the sea at this time. 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 small in the warm season.

bay Nagaevo

In summer, the air warms up unevenly over the entire sea. The average monthly air temperature in August decreases from southwest to northeast from 18° in the south to 12–14° in the center and to 10–10.5° in the northeast of the Sea of ​​Okhotsk. During the warm season over southern part oceanic cyclones quite often pass through the seas, which 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 of this sea.
Quite a few mostly small rivers flow into the Sea of ​​Okhotsk, therefore, with such a significant volume of its waters, the continental runoff is relatively small. It is equal to approximately 600 km3/year, while about 65% is provided by the Amur. Other relatively large rivers - Penzhina, Okhota, Uda, Bolshaya (in Kamchatka) - bring much less fresh water. It arrives mainly in spring and early summer. At this time, the influence of continental runoff is most noticeable, mainly in the coastal zone, near the mouth areas of large rivers.

Geographical position, large extent along the meridian, monsoonal change of winds and good connection of the sea with the Pacific Ocean through the Kuril Straits are the main natural factors, which most significantly affect the formation of the hydrological conditions of the Sea of ​​Okhotsk. The values ​​of heat input and output in the sea are determined mainly by radiative heating and cooling of the sea. The heat brought by the Pacific waters is of subordinate importance. However, for the water balance of the sea, the inflow and outflow of water through the Kuril Straits plays a decisive role. The details and quantitative indicators of water exchange through the Kuril Straits have not yet been studied enough, but the main ways of water exchange through the straits are known. The flow of surface Pacific waters into the Sea of ​​Okhotsk occurs mainly through the northern straits, in particular through the First Kuril. In the straits of the middle part of the ridge, both the inflow of Pacific waters and the outflow of Okhotsk waters are observed. Thus, in the surface layers of the Third and Fourth Kuril Straits, apparently, there is a runoff of water from the Sea of ​​Okhotsk, while in the bottom layers there is an inflow, and in the Bussol Strait, on the contrary: in the surface layers, an inflow, in the deep layers, a drain. In the southern part of the ridge, mainly through the straits of Ekaterina and Friza, there is mainly a runoff of water from the Sea of ​​Okhotsk. The intensity of water exchange through the straits can vary significantly. In general, in the upper layers of the southern part 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 influx of Pacific waters generally prevails.
The inflow of Pacific waters largely affects the distribution of temperature, salinity, formation of the structure and general circulation of the waters of the Sea of ​​Okhotsk.

Cape Stolbchaty, Kunashir Island, Kuril Islands

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

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 (Fig. 39). In August, the warmest (up to 18-19 °) waters adjacent to the island. Hokkaido. In the central regions of the sea, the water temperature is 11-12°. The coldest surface waters are observed near about. Iona, near Cape Pyagin and near the Kruzenshtern Strait. In these areas, the water temperature is kept within 6-7 °. 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 100–200 m. rises to 1–2° in the southern part of the sea; near the Kuril Straits, the water temperature drops from 2.5–3.0° on the surface to 1.0–1.4° at 300–400 m horizons and then gradually rises to 1, 9-2.4° at the bottom.

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 decrease in temperature to values ​​of −1.0–1.2° is observed between horizons of 50–75 m; in horizons of 200-250 m it is 1.5-2.0°. From here, 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° at the surface to 3–8° at a 25 m horizon, then to 1.6–2.4° at a 100 m horizon and down to 1 .4—2.0° at the bottom. The vertical temperature distribution in summer is characterized by a cold intermediate layer, a remnant of the winter cooling of the sea (see Fig. 39). In the northern and central regions of the sea, the temperature 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.

The distribution of salinity in the Sea of ​​Okhotsk varies relatively little with seasons and is characterized by its increase in the eastern part, which is under the influence of Pacific waters, and its decrease in the western part, desalinated by continental runoff (Fig. 40). In the western part, salinity on the surface is 28–31‰, and in the eastern part it is 31–32‰ or 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 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 the 100 m horizon, the salinity is 34.0‰, and further towards the bottom it increases insignificantly, by only 0.5–0.6‰. In individual bays and straits, salinity and its stratification may differ significantly from the open sea, depending on local hydrological conditions.

Temperature and salinity determine the values ​​and distribution of the density of the waters of the Sea of ​​Okhotsk. In accordance with this, denser waters are observed in winter in the northern and central ice-covered regions of the sea. Some less density in a 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. Density increases with depth. In winter, it rises relatively slightly from the surface to the bottom. In summer, its distribution in the upper layers depends on the temperature values, and on the middle and lower horizons on salinity. IN summer time a noticeable density stratification of the waters along the vertical is created, the density increases especially significantly at the horizons of 25-35-50 m, which is associated with the heating of waters in open areas and desalination near the coast.

Cape Nyuklya (Sleeping Dragon) near Magadan

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

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

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

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

The deep Pacific water mass is the water of the lower part of the warm layer of the Pacific Ocean, which enters the Sea of ​​Okhotsk at horizons below 800–2000 m, i.e., below the depth of the waters descending in the straits, and manifests itself in the sea as a warm intermediate layer. This water mass is located on the horizons of 600-1350 m, has a temperature of 2.3°C 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 the rise of waters, and the smallest values ​​of the characteristics are characteristic of the western and southern regions, where the waters sink.
The water mass of the Southern Basin is of Pacific origin and represents the deep water of the northwestern part of the Pacific Ocean from a horizon of 2300 m, corresponding to the maximum depth of the threshold in the Kuril Straits (Bussol Strait). The considered water mass generally fills the named basin from the horizon of 1350 m to the bottom. It is characterized by a temperature of 1.85° and a salinity of 34.7‰, which vary only slightly with depth.
Among the identified water masses, the Sea of ​​Okhotsk and the deep Pacific are the main ones and differ from each other not only in thermohaline, but also in hydrochemical and biological indicators.

Under the influence of winds and water inflow through the Kuril Straits, character traits system of non-periodic currents of the Sea of ​​Okhotsk (Fig. 41). 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 circulations and extensive areas of cyclonic water circulation can be traced in the sea.

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

Non-periodic currents on the surface of the Sea of ​​Okhotsk are most intense off the western coast of Kamchatka (11–20 cm/s), in Sakhalin Bay (30–45 cm/s), in the region of the Kuril Straits (15–40 cm/s), over the South 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 on its periphery. In the central part of the sea, velocities vary from 2 to 10 cm/s, with velocities below 5 cm/s predominating. A similar picture is also observed in the Shelikhov Bay, rather strong currents near the coast (up to 20–30 cm/s) and low velocities in the central part of the cyclonic gyre.

Periodic (tidal) currents are also well expressed in the Sea of ​​Okhotsk. Here their various types are observed: semidiurnal, diurnal and mixed with a predominance of semidiurnal or diurnal components. The velocities of tidal currents are different - 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, the velocities of tidal currents increase significantly; for example, in the Kuril Straits they reach 2–4 m/s.
The tides of the Sea of ​​Okhotsk have a very complex character. A tidal wave enters from the south and southeast from the Pacific Ocean. The semidiurnal wave moves to the north, and at the 50° parallel it is divided into two branches: the western one turns to the northwest, forming amphidromic regions to the north of Cape Terpeniya and in the northern part of Sakhalin Bay, the eastern one moves towards the Shelikhov Bay, at the entrance to which arises another amphidrome. The diurnal wave also moves north, but at the latitude of the northern tip of Sakhalin it is divided into two parts: one enters Shelikhov Bay, the other reaches the northwestern coast.

There are two main types of tides in the Sea of ​​Okhotsk: diurnal and mixed. The most common are diurnal tides. They are observed in the Amur Estuary, Sakhalin Bay, the Kuril Islands, off the western coast of Kamchatka and in Penzhinsky Bay. Mixed tides are observed on the northern and northwestern coasts of the sea and in the area of ​​the Shantar Islands.
The highest tides were recorded in the Penzhina Bay near Cape Astronomichesky (up to 13 m). These are the highest tides for the entire coast of the USSR. In second place is the region of the Shantar Islands, where the tide exceeds 7 m. The tides are very significant in the Sakhalin Bay and in the Kuril Straits. In the northern part of the sea, the tides reach up to 5 m. 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 effect 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 ice-free areas 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 restless are the southern and southeastern regions of the sea, where the average frequency of storm waves is 35 -50%, and in the northwestern part it decreases to 25-30%. In case of strong waves, a crowd forms in the straits between the Kuril Islands and between the Shantar Islands.

Severe and long winters with strong northwest winds contribute to the development of intense ice formation in the Sea of ​​Okhotsk. The ice of the Sea of ​​Okhotsk is exclusively of local formation. There are both fixed ice (fast ice) and floating ice, which are the main form of sea ice. In one quantity or another, ice is found in all areas of the sea, but in summer the entire sea is cleared of ice. The exception is the region of the Shantar Islands, where ice can persist in summer.
Ice formation begins in November in the bays and bays 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 parts of the sea. In ordinary years, the southern boundary of a relatively stable ice cover curves northward 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.

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

The southern coast of Kamchatka and the Kuril Islands are areas with low ice cover, where ice stays on average no more than three months a year. The thickness of the ice that grows during the winter reaches 0.8-1.0 m. Strong storms and tidal currents break the ice cover in many areas of the sea, forming hummocks and large leads. In the open part of the sea, solid immovable ice is never observed; usually, ice drifts here in the form of vast fields with numerous leads. Part of the ice from the Sea of ​​Okhotsk is carried into the ocean, where it breaks up and melts almost immediately. IN harsh winters floating ice is pressed against the Kuril Islands by northwestern winds and clogs some of the straits. Thus, in the winter time in the Sea of ​​Okhotsk there is no such place where an encounter with ice would be completely excluded.

hydrochemical conditions.
Due to the constant water exchange with the Pacific Ocean through the deep Kuril Straits, the chemical composition of the waters of the Sea of ​​Okhotsk generally does not differ from that of the ocean. The values ​​and distribution of dissolved gases and biogenic substances in the open areas of the sea are determined by the inflow of Pacific waters, and in the coastal part, coastal runoff has a certain effect.

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

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

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

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

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

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SOURCE OF INFORMATION AND PHOTO:
Team Nomads
http://tapemark.narod.ru/more/18.html
Melnikov A. V. Geographical names of the Russian Far East: Toponymic Dictionary. — Blagoveshchensk: Interra-Plus (Interra+), 2009. — 55 p.
Shamraev Yu. I., Shishkina L. A. Oceanology. L.: Gidrometeoizdat, 1980.
Lithosphere of the Sea of ​​Okhotsk
The Sea of ​​Okhotsk in the book: A. D. Dobrovolsky, B. S. Zalogin. Seas of the USSR. Moscow publishing house. un-ta, 1982.
Leontiev V.V., Novikova K.A. Toponymic Dictionary of the North-East of the USSR. - Magadan: Magadan book publishing house, 1989, p 86
Leonov A.K. Regional oceanography. - Leningrad, Gidrometeoizdat, 1960. - T. 1. - S. 164.
Wikipedia site.
Magidovich IP, Magidovich VI Essays on the history of geographical discoveries. - Enlightenment, 1985. - T. 4.
http://www.photosight.ru/
photo: O.Smoly, A.Afanasiev, A.Gill, L.Golubtsova, A.Panfilov, T.Selena.

The Sea of ​​Okhotsk was discovered during the first campaigns of the Cossacks through Siberia to the Pacific Ocean.

The local hunting tribes called it Lam - which means: “water”, “sea”, and from this word one of the first names of the sea came from among Russian sailors - “Lamskoye”, and the name of the coastal Tungus - “Lamuts”. Sometimes the sea was also called Tunguska.

However, another name gradually came into use and was fixed, namely, the Sea of ​​Okhotsk. The water area is 1603 thousand km².

Vsevolod Sibi... The coldest... Islands of the Hunts...

Subsequently, when Kamchatka was discovered and trips along the coast and the sea to this rich peninsula and to the mouth of the Penzhina River became more frequent, other names for the sea began to be used - "Kamchatka" and "Penzhina". However, these names did not take root.

It would seem, why should the sea be named after a small river that flows into it between 59 and 60 degrees north latitude? You can find much larger and full-flowing rivers flowing into this sea - like the same Penzhina. Why was their name not associated with the name of the sea? In this case, the matter depended not on the size of the river, but on its role in the life of coastal explorers.

The Cossacks, having left Yakutsk, moved east not straight through the mountains and taiga, but along a winding path along the rivers and portages between them. The caravan trail eventually led them to the Okhota River, and along it to the seashore.

Now Okhotsk is one of the ordinary port points and has lost its former significance. Other, much larger and more important centers arose along the coast.

But the surviving name of the sea testifies to the historical role of the river and the port, from which the Russian people began the development of a large sea area.

Almost everywhere the shores of the Sea of ​​Okhotsk are high and rocky. From afar, from the sea, they stand out on the horizon with black stripes framed on top by brown-green patches of vegetation. Only in some places - off the western coast of Kamchatka, off the northern part of Sakhalin - wide low-lying areas approach the sea.

The bottom of the Sea of ​​Okhotsk is similar in some respects to the bottom of the Sea of ​​Japan: both here and there, despite the great depths, there are underwater hollows, indicating that even in the Quaternary period, the area of ​​\u200b\u200bthe current sea stood high above ocean level and two huge rivers flowed through it - Cupid and Penzhina. Then a geological catastrophe occurred - part of the mainland sank and was flooded with the ocean. This is how the relatively young Sea of ​​Okhotsk was formed.

According to geologists, the eastern part of the Sea of ​​Okhotsk is one of the "restless" areas the globe. Until now, there are large fluctuations - shifts of the earth's crust.

We can feel and see them through earthquakes, volcanic eruptions, changes in the shape of islands.

Academician A. Zavaritsky believes that the Kamchatka-Kuril region is the most interesting region of the globe for science.

Often in this part of the Pacific Ocean there are underwater volcanic eruptions and underwater earthquakes. The originality of the area on the Kuril Islands is especially noticeable.

The ridge of the Kuril Islands, lying on the border between the Sea of ​​Okhotsk and the open part of the ocean, is quite special world. About thirty large and small islands and many rocks of volcanic origin are included in this range. Many islands are crowned high mountains, up to one and a half to two kilometers high. On many islands, hot springs spring from underground with a water temperature of 35 to 70 °. Some of the springs have healing properties. Smoke rises above some mountains that are active volcanoes.

There are about thirty active volcanoes on the islands. This shows that in the bowels of the earth here and now it is restless. Sometimes earthquakes in the ocean produce waves several tens of meters high, which roll over an enormous distance. One of these waves, the ship "Natalia" in 1780 was thrown into the depths of the island of Urup 300 meters from the coast. The ship remained ashore. A laconic entry has been preserved about this: “January 8th. In 1780, there was a severe earthquake, the sea rose so high that the gukor - that is, the ship that was in the harbor - was carried to the middle of the island.

Severe living conditions on the Kuril Islands, especially in the northern ones. ocean waves they hit the rocky shores with noise, breaking into millions of spray. Droplets of water, picked up by the wind, rush through the islands. Fogs linger here for a long time. Strong storms often occur in winter.

Video: Sea of ​​Okhotsk:...

This sea has several names - the Evenki called it the Lamsky Sea (Lam in Evenki - the sea), sometimes it is called the Kamchatka Sea. The Japanese call the sea "Hakkai" - the northern sea. The name Okhotskoye is connected with the name of the river Okhota, which flows into it.

The Sea of ​​Okhotsk is located near the Eurasian continent between the Kamchatka Peninsula and the mainland. In the south, it is delimited from the Pacific Ocean by the ridge of the Kuril Islands, the islands of Sakhalin and Hokkaido, and is connected to the Sea of ​​Japan through the La Perouse and Nevelskoy straits. The sea occupies an area of ​​1583 thousand sq. km, its average depth is 177 m, the largest is 3372 m (in the area of ​​the Kuril basin).

The location of the sea complete map Pacific - .

There are many bays along the coastline, the largest ones are: Shelikhov, Sakhalin, Udskaya Bay, Tauyskaya Bay, etc. north coast Sakhalin is flat. Large rivers flowing into the Sea of ​​Okhotsk: Amur, Okhota, Uda, Gizhiga, Penzhina.
There are many islands in the shelf zone: Shantar, Zavyalova, Spafareva, etc.

The bottom relief is evener than that of the neighbor - the Bering Sea. Only in the south is the deep-water Kuril basin. The northern shelf part of the sea bottom is shallow. In the zone of the continental shelf, sandy, pebbly-sandy, rocky and silty-sandy soils predominate, in the deep-water zone - silty soils.

The climate of the area where the sea is located is temperate. For most of the year, cold dry winds blow from Eurasia, cooling the sea, especially its northern regions. In winter, in some places the air temperature drops below 20 degrees C, in summer it warms up to + 12- + 18 degrees C. The upper layers of water have a temperature slightly above zero in winter, in summer they can warm up to 15 degrees C (in the south).
The currents are directed counterclockwise (cyclonic). The tides in different areas are very different.
The maximum height of the tides (more than 12 meters) is noted in the Penzhina Bay.
The northern part of the sea has been covered with ice since November, the southern and central ones remain open, but severe and prolonged storms often rage here.

Animal and plant world The Sea of ​​Okhotsk has an arctic character, but to the south there are more and more representatives of temperate flora and fauna.

The phytoplankton of the sea is dominated by diatoms. Thanks to good conditions for the development of phytoplankton (water temperature, good mixing of surface layers with deeper ones), phytoalgae develop rapidly. Zooplankton, the main consumer of phytoalgae, is represented by small organisms - copepods, jellyfish, larvae of mollusks and worms, etc.
The richest and most widespread group of plant organisms in the coastal zone are brown algae, including such a valuable representative as sea kale (or kelp). This algae is widely used in the food industry and in medicine. Red algae are also common in the Sea of ​​Okhotsk, and green algae in the northwestern part.

Coastal and shelf areas of the sea are inhabited by various molluscs (mussels, littorinas, cephalopods, etc.), crustaceans (crabs, shrimps, etc.), echinoderms (sea urchins, starfish) and other invertebrates. There are also many different bottom fish species (gobies, flounders, etc.)

The Sea of ​​Okhotsk is especially rich in crabs - in terms of the reserves of commercial species of these crustaceans, it ranks first in the world. More than 80% of the famous king crab, which is found in the Sea of ​​Japan and in the south of the Bering Sea. This huge crab (however, not even a crab, but a sea crayfish - it has ten legs, like crayfish), reaches a leg span of 1.5 meters! True, the body itself (cephalothorax) is not so impressive - up to a quarter of a meter in diameter. The Kamchatka crustacean miracle weighs up to 7 kg.

Marine mammals also live here: whales (humpback whales, gray whales, sperm whales, killer whales), seals (seals), fur seals.

Coastal cliffs, as in many northern seas, often become places for sea birds to arrange bird rookeries.

The fish world of the Sea of ​​Okhotsk is represented by more than 200 species of fish, including many valuable commercial ones. Herring, cod, flounder, navaga, pollock, capelin are caught here. The most valuable species of commercial fish are salmon (pink salmon, chum, chinook, sockeye salmon, coho salmon).

The Sea of ​​Okhotsk is a marginal sea in the northwestern part of the Pacific Ocean.

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

The coastline is slightly indented, the largest bays are: Academies, Aniva, Sakhalin, Patience, Tugursky, Ulbansky, Shelikhova (with Gizhiginskaya and Penzhinskaya lips); Tauyskaya, Udskaya lips. The north, northwestern shores are predominantly elevated and rocky, mostly abrasion, in some places strongly altered by the sea; in Kamchatka, in northern parts Sakhalin and Hokkaido, as well as at the mouths of large rivers - low-lying, largely accumulative. Most of the islands are located near the coast: Zavyalova, Spafaryeva, Shantarsky, Yamsky, and only a small island of Iona is located in the open sea.

relief and geological structure bottom.

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

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

Climate.

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

hydrological regime.

Large rivers flow into the Sea of ​​Okhotsk: Amur, Bolshaya, Gizhiga, Okhota, Penzhina, Uda. The river runoff is about 600 km3/year, about 65% falls on the share of the Amur. Desalinization of the surface layer of the sea is noted. water due to the excess of river runoff over evaporation. The geographical position of the Sea of ​​Okhotsk, in particular, its large extent along the meridian, the monsoon wind regime, water exchange through the straits of the Kuril ridge with the Pacific Ocean determine the features of the hydrological regime. Overall Width of all the Kuril straits reaches 500 km, but the depths above the rapids in the straits vary greatly. For water exchange with the Pacific Ocean, the most important are the Bussol straits with a depth of more than 2300 m and Kruzenshtern - up to 1920 m. This is followed by the Frieze, Fourth Kuril, Rikord and Nadezhda straits, all with depths at the thresholds of more than 500 m. The remaining straits have depths of less than 200 m and small cross-sectional areas. In shallow straits, unidirectional flows into the sea or ocean are usually observed. In deep straits, two-layer circulation prevails: in the near-surface layer in one direction, in the near-bottom one in the opposite direction. In the Bussol Strait, Pacific waters enter the sea in the surface layers, and in the bottom layers there is a runoff to the ocean. In general, the flow of the Sea of ​​Okhotsk waters predominates in the southern straits, while the inflow of the Pacific Ocean waters predominates in the northern straits. The intensity of water exchange through the straits is subject to means. seasonal and annual variability.

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

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

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

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

Research history.

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

Economic use.

In the Sea of ​​Okhotsk, there are about 300 species of fish, of which about 40 species are commercial, including cod, pollock, herring, saffron cod, sea bass. Salmonids are widespread: pink salmon, chum salmon, sockeye salmon, coho salmon, chinook salmon. Whales, seals, sea lions, fur seals live. Crabs are of great economic importance (1st place in the world in terms of stocks of commercial crab). The Sea of ​​Okhotsk is promising in terms of hydrocarbons, the explored oil reserves are over 300 million tons. The largest deposits have been discovered on the shelves of the Sakhalin Islands, Magadan and West Kamchatsky (see the article Okhotsk oil and gas province). On the Sea of ​​Okhotsk pass sea ​​routes connecting Vladivostok with northern regions Far East and the Kuril Islands. Major ports: Magadan, Okhotsk, Korsakov, Severo-Kurilsk.

Tidal phenomena in the area of ​​the Kuril ridge

Tides are the dominant factor that determines the dynamics of waters in the straits, and to a large extent determine changes in the vertical and horizontal structure of the waters. The tides in the region of the ridge, as in the Sea of ​​Okhotsk, are formed mainly by tidal waves propagating from the Pacific Ocean. Own tidal motions of the Sea of ​​Okhotsk, due to the direct impact of tide-forming forces, are negligible. Tidal waves in the northwestern part of the Pacific Ocean are predominantly progressive in nature and move in a southwesterly direction along the Kuril ridge. The speed of movement of tidal waves in the ocean when approaching the Kuril ridge reaches 25-40 knots (12-20 m/s). The amplitude of tidal level fluctuations in the ridge zone does not exceed 1 m, and the speed of tidal currents is about 10-15 cm/s. In the straits, the phase velocity of tidal waves decreases, and the amplitude of tidal level fluctuations increases to 1.7-2.5 m. Here, the velocities of tidal currents increase to 5 knots (2.5 m/s) or more. Due to the multiple reflection of tidal waves from the shores of the Sea of ​​Okhotsk, complex translational-standing waves take place in the straits themselves. Tidal currents in the straits have a pronounced reversal character, which is confirmed by measurements of currents at daily stations in the Bussol, Friza, Ekaterina and other straits. The horizontal orbits of tidal currents, as a rule, are close in shape to straight lines oriented along the straits.

Wind waves in the Kuril region

In summer, both from the Sea of ​​Okhotsk and from the ocean side of the Kuril Islands, large waves (height 5.0 m or more) occur less frequently than in 1% of cases. The frequency of waves with gradations of 3.0–4.5 m is 1–2% from the Sea of ​​Okhotsk side and 3–4% from the ocean side. For a wave height gradation of 2.0-2.5 m in the Sea of ​​Okhotsk, the frequency is 28-31%, and from the Pacific Ocean - 32-33%. For weak waves of 1.5 m or less on the Sea of ​​Okhotsk side, the frequency is 68-70%, and on the ocean side - 63-65%. The prevailing wave direction in the Kuril part of the Sea of ​​Okhotsk is from the southwest in the south of the region and the central Kuril Islands, to the northwest - in the north of the region. From the ocean side of the Kuril Islands in the south, the southwestern direction of waves prevails, and in the north, northwestern and southeastern waves are observed with equal probability.

In autumn, the intensity of cyclones increases sharply; wind speed, which generate larger waves. During this period, along the Sea of ​​Okhotsk coast of the islands, waves with a height of 5.0 m or more make up 6-7% of the total number of wave heights, and from the ocean side - 3-4%. The frequency of occurrence of the northwestern, northeastern and southeastern directions is increasing. Dangerous waves are produced by cyclones (typhoons) with a pressure in the center of less than 980 hPa and large baric pressure gradients of 10-12 hPa per 1° of latitude. Usually in September, typhoons come out in southern part Sea of ​​Okhotsk, moving along the Kuril ridge

In winter, the intensity of passing cyclones increases. The frequency of waves with a height of 5.0 m or more at this time is 7-8% on the Sea of ​​Okhotsk side, and 5-8% on the ocean side. The north-western direction of the waves and the excitement of the adjacent rhumbs predominate.

In spring, the intensity of cyclones drops sharply, their depth and radius of action are significantly reduced. The frequency of large waves over the entire water area is 1% or less, and the direction of waves changes to southwest and northeast.

Ice conditions

In the Kuril Straits in the autumn-winter period, due to intense tidal mixing and the inflow of warmer waters from the Pacific Ocean, the water temperature on the surface does not reach the negative values ​​necessary for the onset of ice formation. However, constant and strong northerly winds in winter are the main reason for the drift of floating ice in the study area. In severe winters, floating ice goes far beyond its average position and reaches the Kuril Straits. In January, individual tongues of floating ice in severe ice cover years leave the Sea of ​​Okhotsk into the ocean through the Ekaterina Strait, spreading 30-40 miles into the open part of the ocean. In February, near the South Kuril Islands, the tongues of ice move to the southwest, along the island of Hokkaido, to Cape Erimo and further south. The width of the ice mass in this case can reach 90 miles. Significant ice masses can be observed along Onekotan Island. The width of the ice strip here can reach 60 miles or more. In March, in extremely difficult years, ice comes out into the open ocean from the Sea of ​​Okhotsk from the massif in the southwest of the sea through all the straits, starting from Krusenstern and further south. Tongues of ice emerging from the straits flow southwest along the Kuril Islands, and then along the island of Hokkaido to Cape Erimo. The width of the ice mass in its various places can reach 90 miles. Off the eastern coast of the Kamchatka Peninsula, the width of the ice massif can reach more than 100 miles, and the massif can spread to the island of Onekotan. In April, floating ice can exit through any strait of the Kuril chain from the Krusenstern Strait and to the south, and the width of the ice tongues does not exceed 30 miles.

Influence of Atmospheric Circulation on Water Dynamics

A feature of the atmospheric processes of the Kuril region, as well as the entire Sea of ​​Okhotsk, is the monsoonal nature of the circulation of the atmosphere (Fig. 2.3). This is the predominance of southeasterly winds during the summer monsoon and reverse wind directions in the winter. The intensity of monsoon development is determined by the development of large-scale atmospheric processes associated with the state of the main atmospheric action centers that regulate atmospheric circulation over the seas of the Far East region. A fairly close causal relationship has been revealed between the features of atmospheric circulation and the variability in the intensity of development of one or another link in the system of currents in the Kuril Islands region, which, in turn, largely determines the formation of the temperature background of the region's waters.

CO - "cyclones over the ocean"; OA - "Okhotsk-Aleutian" /

Characteristics of the Soya and Kuril currents in September 1988-1993. (1Sv \u003d 10 6 m 3 / s)

The given data on the state of the Kuril currents in September for the period from 1988 to 1993. indicates the interannual variability of the characteristics of the system of these currents.

In the spring period of the year, with the predominance of the Okhotsk-Aleutian type of atmospheric circulation, a significant penetration of the Soya current into the Sea of ​​Okhotsk was noted in the subsequent summer season and, as a result, the formation of an increased temperature background of the water area in the South Kuril region. With the predominance of the northwestern type of atmospheric circulation in the spring period, in the subsequent summer season, on the contrary, there was an insignificant penetration of the warm Soya Current into the Sea of ​​Okhotsk, a greater development of the Kuril Current, and the formation of a lower temperature background in the water area.

The main features of the structure and dynamics of the waters of the Kuril region

The structural features of the waters of the Kuril region of the Pacific Ocean are associated with the Kuril current, which is the western boundary flow in the subpolar circular circulation of the northern part of the Pacific Ocean. The current is traced in the waters of the western modification of the subarctic structure, which has the following characteristics water masses :

1. Surface water mass(0-60 m); in spring °С=2-3°, S‰=33.0‰; in summer °С=8°, S‰=33.0‰.

2. Cold intermediate layer(60-200 m); ° С min \u003d 0.3 °, S ‰ \u003d 33.3 ‰ with a core at a depth of 75-125 m.

3. Warm intermediate layer(200-800 m); °С max =3.5°, S‰=34.1‰ with a core at a depth of 300-500 m.

4. Deep(800-3000 m); ° С = 1.7 °, S‰ = 34.7‰.

5. bottom(more than 3000 m); ° С = 1.5 °, S‰ = 34.7‰.

The Pacific waters near the northern straits of the Kuril chain are significantly different from the waters of the southern straits. The waters of the Kuril Current, which are formed by very cold and more desalinated waters of the eastern coast of the Kamchatka Peninsula and Pacific waters, mix with the transformed Sea of ​​Okhotsk waters in the zone of the Kuril straits. Further, the waters of the Oyashio Current are formed by a mixture of the Sea of ​​Okhotsk waters transformed in the straits and the waters of the Kuril Current.

General scheme water circulation In the Sea of ​​Okhotsk, in general, it is a large cyclonic gyre, which in the northeastern part of the sea is formed by surface, intermediate and deep Pacific waters that enter during water exchange through the northern Kuril straits. As a result of water exchange through the southern and central Kuril straits, these waters partially penetrate into the Pacific Ocean and replenish the waters of the Kuril Current. The cyclonic current pattern typical for the Sea of ​​Okhotsk as a whole, due to the prevailing cyclonic atmospheric circulation of the atmosphere over the sea, is corrected in the southern part of the sea by the complex bottom topography and local features of the water dynamics of the Kuril Straits zone. In the region of the southern basin, a stable anticyclonic circulation is noted.

The structure of the waters of the Sea of ​​Okhotsk, defined as the Sea of ​​Okhotsk variety of the subarctic water structure, consists of the following water masses:

1. Surface water mass(0-40 m) with temperature and salinity of about 2.5° and 32.5 in spring and 10-13° and 32.8, respectively, in summer.

2. Cold intermediate water mass(40-150 m), formed in the Sea of ​​Okhotsk in winter, with core characteristics: ° С min = -1.3 °, S = 32.9 at a depth of 100 m.

Along the Kuril Islands in the Sea of ​​Okhotsk, there is a sharp break in the core of the cold intermediate layer with a minimum temperature below +1°C at a distance of 40-60 miles from the coast of the islands. The “clipping” of the cold intermediate layer indicates the existence of a pronounced frontal separation between the Sea of ​​Okhotsk intermediate waters and transformed waters in the straits during tidal vertical mixing. The frontal section limits the distribution of a patch of colder surface waters in the water area along the Kuril Islands. That is, the cold intermediate layer in the Sea of ​​Okhotsk is not related to that in the Kuril-Kamchatka current and is determined by the winter temperature conditions of the region.

3. Transitional water mass(150-600 m), formed as a result of tidal transformation of the upper layer of the Pacific and Sea of ​​Okhotsk waters in the zone of the Kuril Straits (T°=1.5°, S=33.7).

4. Deep water mass(600-1300m), which manifests itself in the Sea of ​​Okhotsk in the form of a warm intermediate layer: ° С = 2.3 °, S = 34.3 at a depth of 750-1000 m.

5. Water mass of the southern basin(more than 1300 m) with characteristics: ° С = 1.85, S = 34.7.

In the southern part of the Sea of ​​Okhotsk surface water mass has three modifications. The first modification is low-salt (S<32,5‰), центральная охотоморская формируется преимущественно при таянии льда и располагается до глубины 30 м в период с апреля по октябрь. Вторая - Восточно-Сахалинского течения, наблюдается в слое 0-50 м и характеризуется низкой температурой (<7°) и низкой соленостью (<32,0‰). Третья - теплых и соленых вод течения Соя, являющегося продолжением ветви Цусимского течения, распространяющегося вдоль охотоморского побережья о.Хоккайдо (в слое 0-70 м) от пролива Лаперуза до южных Курильских островов. С марта по май имеет место “предвестник” течения Соя (Т°=4-6°, S‰ =33,8-34,2‰), а с июня по ноябрь - собственно теплое течение Соя с более высокой температурой (до 14-17°) и более высокой соленостью (до 34,5‰).

Straits of the Kuril chain

In the Kuril archipelago, approximately 1200 km long, there are 28 relatively large islands and many small ones. These islands form the Greater Kuril Ridge and the Lesser one, located along the ocean side of the Greater Kuril Ridge, 60 km southwest of the latter. The total width of the Kuril Straits is about 500 km. Of the total cross-sections of the straits, 43.3% falls on the Bussol Strait (threshold depth 2318 m), 24.4% - on the Krusenstern Strait (threshold depth 1920 m), 9.2% - on the Friza Strait and 8.1% - to the IV Kuril Strait. However, the depth of even the deepest of the Kuril Straits is much less than the maximum depth of the areas of the Sea of ​​Okhotsk (about 3000 m) and the Pacific Ocean (more than 3000 m) adjacent to the Kuril Islands. Therefore, the Kuril ridge is a natural threshold that separates the sea basin from the ocean. At the same time, the Kuril Straits are precisely the zone in which water exchange takes place between these basins. This zone has its own features of the hydrological regime, which differ from the regime of the adjacent deep-sea regions of the ocean and sea. Features of the orography and topography of the bottom of this zone have a corrective effect on the formation of the structure of waters and the manifestation of such processes as tides, tidal mixing, currents, etc.

Based on the generalization of long-term observational data, it has been established that in the zone of the straits, a more complex hydrological structure of waters is observed than previously thought. Firstly, the transformation of waters in the straits is not unambiguous. The transformed water structure, which has the characteristic features of the Kuril variety of the subarctic water structure (characterized by negative temperature anomalies and positive salinity anomalies on the surface in the warm half of the year, a thicker cold intermediate layer and smoother extrema of intermediate water masses, including a positive minimum temperature anomaly), is observed mainly on the shelf of the islands, where tidal mixing is more pronounced. In shallow water, tidal transformation leads to the formation of a vertically uniform water structure. In the deep water areas of the straits, well-stratified waters are observed. Secondly, the difficulty lies in the fact that the zone of the Kuril Straits is characterized by the presence of heterogeneities of different scales, which are formed during eddy formation and frontogenesis in the process of contact between the streams of the Kuril currents, which occurs against the background of tidal mixing. At the same time, in the structure of thermohaline fields there is a change in the position of the boundaries and extrema of the intermediate layers. In the areas of vortices, as well as in the areas of cores of flows that carry and retain their characteristics, localization of homogeneous cores of the minimum temperature of the cold intermediate layer is observed. Third, the structure of waters in the zones of the straits is corrected by the variability of water exchange in the straits. In each of the main Kuril straits in different years, depending on the development of one or another link in the system of currents of the region, either the predominant runoff of the Sea of ​​Okhotsk waters, or the predominant supply of Pacific waters, or two-way circulation of waters is possible.

IV Kuril Strait

IV Kuril Strait - one of the main northern straits of the Kuril Islands. The cross section of the strait is 17.38 km 2, which is 8.1% of the total cross-sectional area of ​​​​all the Kuril straits, its depth is about 600 m. The topographic feature of the strait is its openness towards the Sea of ​​Okhotsk and the presence of a Pacific Ocean.

Thermohaline structure of the waters of the IV Kuril Strait

Due to the complex bottom relief in the strait, the amount of water masses is different. in shallow water vertical mixing leads to homogenization of water. In these cases, only the surface water mass takes place. For the main part of the strait, where the depth is 500-600 m, two water masses are observed - surface and cold intermediate. At deeper stations on the Sea of ​​Okhotsk side, a warmer near-bottom water mass is also observed. At some stations in the strait, a second temperature minimum is observed. Since there is a threshold with depths of about 400 m in the strait from the side of the Pacific Ocean, the water exchange between the Pacific Ocean and the Sea of ​​Okhotsk is practically carried out to the depth of the threshold. That is, the Pacific and Sea of ​​Okhotsk water masses, located at great depths, do not have contact in the strait zone.

Krusenstern Strait

The Kruzenshtern Strait is one of the largest and deepest straits of the Kuril Islands. The cross-sectional area of ​​the strait is 40.84 km2. The threshold of the strait, with depths of 200-400 m, is located on its ocean side. The strait has a trough with depths from 1200 m to 1990 m, through which deep water can be exchanged between the Pacific Ocean and the Sea of ​​Okhotsk. The northeastern part of the strait is occupied by shallow waters with depths of less than 200 m. Simushir and from the north by the island of Shiashkotan.

Thermohaline structure of the waters of the Krusenstern Strait