The Arctic Ocean is the smallest ocean on our planet. Its area is only 14.78 million km2. For this reason, sometimes in foreign literature this body of water is considered an inland sea. However, in Russian classical geography it has always been considered an independent ocean. also the shallowest. It is located in the center and has very harsh climatic conditions. The planet's North Pole is located on its territory. A significant part of the ocean area is made up of marginal seas off the coast and which it washes.
The ocean is of great importance primarily for Russia. Even in ancient times, hundreds of years ago, the inhabitants of the northern lands - the Pomors - mastered its waters, fished here, hunted sea animals, wintered on Spitsbergen and sailed to the mouth of the Ob. The study of the ocean shores began in the 18th century with the organization of the Great Northern Expedition, which described the ocean shores from the mouth of the Pechora to the strait. The circumpolar regions were described by Fridtjof Nansen and Georgiy Yakovlevich Sedov. The possibility of crossing the entire ocean in one navigation was proven by Otto Yulievich Schmidt in 1932; this journey, in fact, marked the beginning of the Northern Sea Route. In 1937, the first polar station “North Pole - 1” was organized on a drifting ice floe. Under the leadership of Ivan Dmitrievich Papanin, a group of four polar explorers drifted on an ice floe from the North Pole to the shores, exploring the features and routes of movement of Arctic floating ice.
The Arctic Ocean is located on the North American and Eurasian Seas. Most of its territory is occupied by the shelf, which accounts for about a third of the total area. The central part is occupied by the Nansen and Amundsen basins, where deep-sea faults and the Mendeleev and Lomonosov ridges pass.
The ocean is located in the Arctic and subarctic zones, which determined its climatic features. Arctic air masses prevail here all year round. However, unlike Antarctica, the climate here is still warmer and milder. This is due to the fact that the ocean retains large reserves of heat, constantly replenished by the waters of the Atlantic. The Arctic Ocean makes the winters of the Northern Hemisphere milder, strange as it may seem at first glance, but if there were land in the north, the same as in the Southern Hemisphere, the climate would be much drier and colder. The warm North Atlantic Current, which penetrates here from the south and is the “heating system” of Europe, is also of great importance here. At the same time, the polar regions of the ocean are under ice. However, in recent decades the ice cover has been rapidly retreating. The melting of the Arctic in the summer of 2007 was record-breaking. According to climatologists, this process will continue. The salinity of the Arctic Ocean is very low. Firstly, fresh water is brought here by the deep rivers of Eurasia and North America, and secondly, ice constantly breaks off from the ice cap, their melting has a very strong desalinating effect on the ocean water, also reducing its salinity. These ice mountains - icebergs penetrate the waters of the North Atlantic, creating a great danger for shipping. As you know, the huge passenger ship Titanic sank when it collided with an iceberg.
The nature of the ocean is rich only in the Atlantic waters. There is a lot of plankton and algae that have adapted to low temperatures. There are many whales, seals, and walruses in the ocean. Polar bears live here and huge “bird colonies” gather here. There are a lot of commercial fish off the coast: cod, navaga, halibut.
The importance of the Arctic Ocean is enormous. Despite the not very large reserves of biological resources, fish and algae are actively harvested here, and seals are hunted. Significant reserves, including gas and oil, are concentrated on the ocean shelf. Without the development and study of the Arctic Ocean, it would be impossible to carry out navigation along the Northern Sea Route, connecting European, Siberian and Far Eastern ports.
The Arctic Ocean is the smallest, shallowest, and freshest of all oceans.
Description and characteristics
The Arctic Ocean is conventionally divided into three parts: the Canadian Basin, the North European and the Arctic. It is located between North America and Eurasia. The small size of the water area allows some geographers to consider the ocean an inland sea of the Atlantic.
Area: 14.75 million sq. km
Average depth: 1225 m, greatest - 5527 m (point in the Greenland Sea)
Average temperature: in winter - from 0°C to -4°C, in summer the water can warm up to +6°C.
Volume: 18.07 million cubic meters
Seas and bays: 11 seas and Hudson Bay occupy 70% of the ocean area.
Currents of the Arctic Ocean
Shipping in the Arctic is less developed than in other oceans, and therefore the currents are far from fully studied. The following are currently known:
Cold:
East Greenlandic- washes Greenland from the east and west and carries the cold waters of the Arctic to the Atlantic. Speed: 0.9-1.2 km/h, water temperature in summer rises to 2°C.
Transarctic- one of the main ocean currents. It originates near the coasts of Chukotka and Alaska thanks to the runoff waters of rivers that flow into the ocean. Next, the current crosses the entire Arctic Ocean and, through the strait between Spitsbergen and Greenland, enters the Atlantic.
This current passes through the entire ocean in a wide strip, capturing the North Pole and ensuring the continuous movement of ice.
Warm:
Gulf Stream represented in the Arctic with its branches. First of all, this is the North Atlantic, which partially reaches the waters of the Arctic Ocean, as well as the Norwegian and North Cape.
Norwegian- washes the shores of the Scandinavian Peninsula and moves further to the northeast, significantly softening the weather and climate in Scandinavia. Speed 30 m/sec, water temperature 10-12°C.
North Cape- branches off from the Norwegian Current and stretches along the northern coast of Scandinavia all the way to the Kola Peninsula. Thanks to the warm waters of the North Cape Current, part of the Barents Sea never freezes. Speed 0.9-1.8 km/h, temperature in winter 2-5°C, in summer - 5-8°C.
Spitsbergen- another branch of the Gulf Stream, a continuation of the Norwegian Current, which moves along the coast of Spitsbergen.
The underwater world of the Arctic Ocean
The harsh conditions of the Arctic zone have caused the poverty of ocean flora and fauna. Exceptions are the North European Basin, the White and Barnets Seas with the richest flora and fauna.
The ocean flora is represented mainly by fucus and kelp. The ocean waters are also rich in phytoplankton, of which there are over 200 species.
The fauna is unevenly distributed. The habitats of animals are greatly influenced not only by water temperature, but also by the currents of the Pacific and Atlantic Oceans.
Fish - more than 150 species (among them commercial fish include salmon, cod, flounder, and herring).
Birds - about 30 species: guillemots, white geese, eiders, guillemots, black geese. Birds live here in colonies.
Mammals: whales, narwhals, walruses, beluga whales, seals.
It should be noted that the fauna of the Arctic Ocean has two features: gigantism and longevity. Jellyfish can reach a diameter of 2 meters, spiders - up to 30 cm. And longevity is explained by the fact that in harsh climatic conditions the development of life cycles occurs much more slowly.
Arctic Ocean Research
Disputes are still ongoing about whether to distinguish this water area as an independent ocean. Many countries officially call it a sea. Even the names are different in different languages.
In 1650, the Dutch geographer Varenius first dubbed the waters of the north an ocean, giving it the name Hyperborean. Other peoples called it Scythian, Tatar, Arctic, Breathing. In the 20s of the 19th century, Russian admiral F. Litke first proposed the full name - the Arctic Ocean. In Western Europe and America, this ocean is called the Arctic Ocean.
The first written mention of the ocean dates back to the 4th century BC. Until the 16th century, research was local in nature. The peoples who lived on the northern coasts of Iceland, Ireland, Scandinavia and Russia roamed the coastal waters where they fished and hunted.
More thorough and large-scale studies of the water area began with the development of trade relations between states. Here are the main dates and the largest openings:
1594-1596 - three expeditions of V. Barents with the goal of finding a northern route to Asia. Barents was the first to spend the winter in the Arctic.
1610 - G. Hudson reached the strait, which now bears his name.
1641-1647 - expedition of S.I. Dezhnev, discovery of the strait between Asia and America, which would later be called the Bering Strait.
1733-1743 - Great Northern Expedition. More than 550 people took part in it. 7 detachments were created under the leadership of V. Bering, H. Laptev, D. Laptev, S. Chelyuskin, F. Minin, G. Gmelin, G. Miller. Each detachment was assigned a separate section of the coast and coastal waters. As a result, scientists received detailed maps of the coast of Siberia, the Bering Strait and the shores of North America were rediscovered, and numerous islands were described and mapped.
1845 - expedition of the Englishman D. Franklin, discovery of the Northwest Passage.
1930s - conquest of the Northern Sea Route.
1937-1938 - the work of the first polar research station "North Pole" was organized on a drifting ice floe.
1969 - W. Herbert's expedition reached the North Pole. This is an officially recognized date, although back in 1908-1909 two Americans, R. Peary and F. Cook, claimed that they had visited the Pole. But many researchers have expressed doubts about the reliability of these claims.
1980 - Russian scientists compiled a detailed atlas of the ocean.
Since the end of the 20th century, a comprehensive study of the ocean has been carried out; numerous institutes and laboratories have been created in Russia, Norway, Iceland, Canada, and the USA.
The Arctic Ocean stores almost a quarter of the world's oil reserves.
Ocean waters form a “dead water” effect. Once trapped, the ship cannot move, even if all engines are running at full power. This happens because surface and subsurface waters have different densities, and internal waves are formed at the junction of them.
In terms of the number of islands, the Arctic Ocean ranks third after the Pacific Ocean. And most of the islands belong to Russia.
Drifting ice floes are used by both humans and animals as a means of transport: people build research stations here, and polar bears use ice floes to cover long distances.
There is no time at the North Pole (as well as at the South Pole). All lines of longitude converge here, so the time always shows noon. People working at the pole usually use the time of the country they come from.
And the sunrise and sunset at the pole occurs once a year! In March, the sun rises, marking the beginning of the polar day, which lasts 178 days. And in September it sets, and the long polar night begins (187 days).
This ocean is recognized as the smallest in area and depth. It is located in the central part of the Arctic. Its location is the key to answering the question of which continents are washed by the Arctic Ocean. Its second name is Polar, and its waters reach the shores of the North American and Eurasian continents.
Characteristics of ocean conditions
The area occupied by the Arctic Ocean is small, and it does not prevent the appearance of a large number of islands in the basin. And these are not small rocks that come to the surface, but continental archipelagos of large areas (Novaya Zemlya, Spitsbergen, Greenland, etc.).
The continents washed by the Arctic Ocean are the northernmost on the planet. Cold waters are partly warmed by warm currents that come from the Atlantic, bypassing Northern Europe. A slightly heated current comes from the side passing through. The circulation of warm air masses also has a certain influence. In winter, the ocean is bound by a thick ice crust; the temperature usually does not rise above -40 ºC.
What continents is washed by the Arctic Ocean?
While studying the Earth's watery shell, you cannot miss the space that connects the two continents. The Polar Ocean is bordered by the following and North America. Access to other oceans occurs through straits between continents.
The main part of the water area consists of seas, most of which are marginal and only one is internal. Many islands are located near continents. washes continents whose shores are located beyond the Arctic Circle. Its waters are located in the harsh Arctic climate zone.
Ocean climate
In geography lessons, schoolchildren are explained which continents are washed by the Arctic Ocean and what its climatic features are. Arctic air is much warmer than Antarctic air. Because the polar waters receive heat from the adjacent oceans. With the last of them, interaction is less active. As a result, it turns out that the Northern Hemisphere is “warmed up” by the Arctic Ocean.
The influence of air currents from the west and southwest led to the formation of the North Atlantic Current. are transported parallel to the coast of the Eurasian continent in an easterly direction. They are met by streams passing through the Bering Strait from the Pacific Ocean.
A well-known natural feature of these latitudes is the presence of an ice crust on the waters. The polar ocean washes the shores of the continents where low temperatures prevail in the Arctic Circle. Covering with ice also occurs due to the low concentration of salts in the surface layer of water. The reason for desalination is abundant river flows from the continents.
Economic use
What continents is washed by the Arctic Ocean? North America and Eurasia. However, it is of greater economic importance for countries that have access to it. The harsh local climate hinders the search for mineral deposits. But, despite this, scientists managed to explore hydrocarbon deposits on the shelf of some northern seas, as well as off the coast of Canada and Alaska.
The fauna and flora of the ocean are not rich. Near the Atlantic, fishing and seaweed production are carried out, as well as seal hunting. Whaling ships operate within strict quotas. (NSR) began to be developed only in the 20th century. Using it, ships can get from Europe to the Far East much faster. Its role in the development of the Siberian region is great. Forest resources and ore are transported from there by sea, and food and equipment are delivered to the region.
The duration of navigation is 2-4 months a year. Icebreakers are helping to extend this period in some areas. The operation of the NSR in the Russian Federation is ensured by various services: polar aviation, a complex of weather observation stations.
History of the study
What continents is washed by the Arctic Ocean? What are the weather and natural conditions like in the Arctic Circle? Polar explorers were looking for answers to these and many questions. The first trips by sea were made on wooden boats. People hunted, fished, and studied the features of northern navigation.
Western sailors in the polar ocean tried to explore a short route from Europe to India and China. The expedition, which began in 1733 and lasted a decade, made a great contribution. The feat of scientists and navigators cannot be underestimated: they mapped the outlines of the coastline from Pechora to the Bering Strait. Information about flora, fauna and weather conditions was collected at the end of the 19th century. In the first half of the next century, passage through the ocean was accomplished during one navigation. The sailors took measurements of depths, the thickness of the ice crust and meteorological observations.
The Arctic Ocean lies between two continents - Eurasia and North America. According to its physical and geographical features, it is divided into the deep-sea Arctic basin, approximately in the center of which the Earth’s North Pole is located, and the marginal Arctic seas, most of them shallow. There are many islands in these seas, some of them are grouped into large and small archipelagos.
The waters of the Arctic Ocean wash the shores of our Motherland from the north. The main route of the Northern Sea Route runs along them - along the White, Barents, Kara, Laptev, East Siberian and Chukchi seas. Most of the Arctic Ocean lies within the Arctic Circle. The most important feature of this area is the polar night and polar day. In Murmansk, the starting point of the Northern Sea Route, the polar night lasts 40 days, the polar day - 58; at Cape Chelyuskin - the northernmost point of the continent - the duration of the polar night is 107 days, the polar day is 123; At the North Pole, the polar night and polar day last approximately six months.
The nature of the Arctic Ocean is extremely harsh. Winter lasts nine to eleven months with severe frosts and severe snowstorms. All visible life freezes. Only occasionally will a lone polar bear pass by in search of food, or a graceful arctic animal, the white arctic fox, will flash past. The short, cold summer, cloudy and damp, is also not encouraging. The sky is almost always covered with a dense layer of low, dull clouds, an annoying drizzling rain falls almost every day, and a fog piercing with dampness often creeps in. Despite the fact that the sun makes its way above the horizon around the clock, it is very rarely possible to see it. The air temperature on Franz Josef Land, Cape Chelyuskin, and Severnaya Zemlya in summer stays around 0°C. On any summer day it can drop to -5°, -10°, heavy snowfall and blizzard are possible.
The Arctic basin is covered with drifting ice fields at all times of the year. As a result of uneven drift, the ice spreads in places, and spaces of open water are formed - leads; in other places, on the contrary, the ice is compressed and, breaking, they form chaotic piles - hummocks. In the marginal seas in winter, floating ice freezes to the shores as stationary ice fast ice. In summer, the fast ice is destroyed and cracked. There are years when the broken ice moves far from the coast, clearing the way for steamships, and sometimes it does not move away at all or does not move far away, making navigation difficult.
The Arctic land also looks harsh. All mainland coasts and islands are bound by permafrost. Many islands are partially or even completely buried by powerful glaciers. There are no trees or bushes anywhere.
The beginning of Russian exploration of the Arctic Ocean dates back to the middle of the 12th century, when the Pomors first came to the shores of the White Sea and then the Barents Sea, where they hunted seals, walruses, whales, polar bears, and valuable fish species. Gradually expanding their fishing areas, the Pomors, apparently in the 14th century. already sailed to Novaya Zemlya and no later than the 16th century - to Spitsbergen.
In 1525, the Russian writer and diplomat Dmitry Gerasimov first expressed the idea of the likely existence of a waterway running along the northern shores of Europe and Asia. Gerasimov's idea served as an impetus for the search for the Northern Sea Route by England and Holland, which equipped them for this purpose in the 16th-17th centuries. several expeditions. However, none of them went further than the western regions of the Kara Sea.
The first English expedition set sail in 1553 from London on three small sailing ships. During a strong storm on the approach to the North Cape, the ships lost each other. Two of them, including the one on which the head of the expedition, Admiral Hugh Willoughby, was, went to Novaya Zemlya or to Kolguev Island, from where they turned back and stopped for the winter on the Murmansk coast, near the mouth of the Varsina River. The first wintering of Europeans in the waters of the Arctic Ocean ended tragically - the entire personnel of both ships, numbering 65 people, died from cold and hunger. The fate of the third ship, commanded by Richard Chancellor, was happier. But his voyage was limited to the lower reaches of the Northern Dvina.
In 1596, a Dutch ship under the command of Jacob Gemskerk and Willem Barents successfully reached the northern shore of Novaya Zemlya. It seemed to the sailors that the desired path to the countries of the East was already open, but their ship was tightly covered with ice in the bay, which they called Ice Harbor. The sailors went ashore and built a house. Several people could not bear the hardships of the harsh winter and died. Barents and many others became seriously ill with scurvy. With the onset of summer, the Dutch abandoned the ship frozen in the ice and went south along the coastal strip of clear water in two boats. Near the island of Mezhdusharsky they were noticed by Russian Pomors hunting here. They supplied the distressed sailors with food and indicated the safest route to return to their homeland. On September 2, 1597, the Dutch arrived safely in Cola, and from there they returned to Amsterdam on a passing ship. But Barents was not among them. The brave navigator died in the first days of sailing on boats.
While the British and Dutch unsuccessfully tried to open the Northern Sea Route, a great movement of Russian Pomors and explorers began to the east. Already in the middle of the 16th century. Pomors mastered the sea route at the mouth of the Ob. Using the tributaries of Siberian rivers, Pomors and explorers from the Ob crossed to the Yenisei and Lena. They made voyages to the Arctic Ocean and along its shores. Thus, the sea route was opened from the mouth of the Yenisei to Pyasina, from the mouth of the Lena to the Olenek and Anabar rivers to the west, to the Yana, Indigirka and Kolyma rivers to the east.
In 1648, a group of sailors led by the “trading man” Fedot Alekseev Popov and the Cossack ataman Semyon Ivanov Dezhnev bypassed the Chukotka Peninsula on kochas and entered the Pacific Ocean. In 1686-1688. The trade expedition of Ivan Tolstoukhov on three kochas circumnavigated the Taimyr Peninsula from west to east. In 1712, explorers Mercury Vagin and Yakov Permyakov first visited Bolshoi Lyakhovsky Island, marking the beginning of the discovery and exploration of the entire group of New Siberian Islands. In a little more than a century, Russian Pomors and explorers traversed the entire Northern Sea Route in separate sections. Dmitry Gerasimov's assumption about the existence of a sea route from Europe to the Pacific Ocean around the northern shores of Eurasia was confirmed.
The seas of the Arctic Ocean are located in the Arctic zone between 70 and 80° N. w. and wash the northern coast of Russia. From west to east, the Barents, White, Kara Sea, Laptev Sea, East Siberian and Chukchi Seas replace each other. Their formation occurred as a result of the flooding of the marginal parts of Eurasia, as a result of which most of the seas are shallow. Communication with the ocean is carried out through wide open spaces of water. The seas are separated from each other by the archipelagos and islands of Novaya Zemlya, Severnaya Zemlya, the New Siberian Islands and Wrangel Island. The natural conditions of the northern seas are very harsh, with significant ice cover from October to May - June. Only the southwestern part of the Barents Sea, where the branch of the warm North Atlantic Current enters, remains ice-free all year round. The biological productivity of the seas of the Arctic Ocean is low, which is associated with unfavorable conditions for the development of plankton. The greatest ecosystem diversity is characteristic only of the Barents Sea, which is also of great fishing importance. The Northern Sea Route passes through the seas of the Arctic Ocean - the shortest distance from the western borders of Russia to the north and Far East - it has a length of 14,280 km from St. Petersburg (via the North and Norwegian Seas) to Vladivostok.Barencevo sea
The Barents Sea washes the coasts of Russia and Norway and is limited by the northern coast of Europe and the archipelagos of Spitsbergen, Franz Josef Land and Novaya Zemlya (Fig. 39). The sea is located within the continental shallows and is characterized by depths of 300-400 m. The southern part of the sea has a predominantly leveled relief, the northern part is characterized by the presence of both hills (Central, Perseus), and depressions and trenches.The climate of the Barents Sea is formed under the influence of warm air masses from the Atlantic and cold Arctic air from the Arctic Ocean, which causes great variability in weather conditions. This leads to significant temperature variations in different parts of the water area. In the coldest month of the year—February—the air temperature varies from 25 °C in the north to -4 °C in the southwest. Cloudy weather usually prevails over the sea.
The salinity of the surface layer of water in the open sea throughout the year is 34.7-35%o in the southwest, 33-34%o in the east, and 32-33%o in the north. In the coastal strip of the sea in spring and summer, salinity drops to 30-32% o, by the end of winter it increases to 34-34.5%.
In the water balance of the Barents Sea, water exchange with neighboring waters is of great importance. Surface currents form a counterclockwise gyre. The role of the warm North Cape Current (a branch of the Gulf Stream) is especially important in the formation of the hydrometeorological regime. In the central part of the sea there is a system of intracircular currents. The circulation of sea waters changes under the influence of changes in winds and water exchange with adjacent seas. Along the coasts, the importance of tidal currents increases, characterized as semidiurnal, the highest height of which is 6.1 m near the Kola Peninsula.
Ice cover reaches its greatest extent in April, when at least 75% of the sea surface is occupied by floating ice. However, its southwestern part remains ice-free in all seasons due to the influence of warm currents. The northwestern and northeastern margins of the sea are completely free of ice only in warm years.
The biodiversity of the Barents Sea stands out among all the waters of the Arctic Ocean, which is associated with natural and climatic conditions. There are 114 species of fish found here, 20 of which are of commercial importance: cod, haddock, herring, sea bass, halibut and others. The benthos is very diverse, among which sea urchins, echinoderms, and invertebrates are common. Introduced back in the 30s. XX century Kamchatka crab adapted to new conditions and began to reproduce intensively on the shelf. The coasts abound with bird colonies. Large mammals include the polar bear, beluga whale, and harp seal.
Haddock, a fish of the cod family, is an important fishery species in the Barents Sea region. Haddock makes long-distance feeding and spawning migrations. Haddock eggs are carried by currents over long distances from their spawning grounds. Fry and juveniles of haddock live in the water column, often hiding from predators under the domes (bells) of large jellyfish. Adult fish lead a predominantly bottom-dwelling lifestyle.
Serious environmental problems in the Barents Sea are associated with contamination from radioactive waste from Norwegian processing plants, as well as the flow of contaminated water from the land surface. The greatest pollution with oil products is typical for the Kola, Teribersky and Motovsky bays.
White Sea
White Sea belongs to the category of internal and is the smallest among the seas washing Russia (Fig. 40). It washes the southern coast of the Kola Peninsula and is separated from the Barents Sea by a line connecting Capes Svyatoy Nos and Kanin Nos. The sea is replete with small islands, among which the most famous are Solovetsky. The shores are indented by numerous bays. The bottom relief is complex; in the central part of the sea there is a closed basin with depths of 100–200 m, separated from the Barents Sea by a threshold with shallow depths. The soils in shallow water are a mixture of pebbles and sand, turning into clayey silt at depths.
The geographic location of the White Sea determines the climatic conditions, where features of both marine and continental climates appear. In winter, cloudy weather sets in with low temperatures and heavy snowfalls, and the climate in the northern part of the sea is somewhat warmer, which is due to the influence of warm air and water masses from the Atlantic. In summer, the White Sea is characterized by cool, rainy weather with average temperatures of +8–+13°C.
The influx of fresh water and insignificant water exchange with neighboring water areas have determined the low salinity of the sea, which is about 26%o near the coasts and 31%o in the deep zones. In the centric part, an annular flow is formed, directed counterclockwise. Tidal currents are semi-diurnal in nature and range from 0.6 to 3 m. In narrow areas, the height of the tide can reach 7 m and penetrate high up the rivers up to 120 km (Northern Dvina). Despite its small area, storm activity is widespread in the sea, especially in the autumn; the White Sea freezes annually for 6-7 months. Fast ice forms near the coast, the central part is covered with floating ice, reaching a thickness of 0.4 m, and in severe winters - up to 1.5 m.
The diversity of ecosystems in the White Sea is much lower than in the neighboring Barents Sea, however, various algae and bottom invertebrates are found here. Among marine mammals, the harp seal, beluga whale, and ringed seal should be noted. In the waters of the White Sea there are important commercial fish: navaga, White Sea herring, smelt, salmon, cod.
In 1928, Soviet hydrobiologist K.M. Deryugin noted in the White Sea the presence of a number of endemic forms due to isolation, as well as a shortage of species compared to the Barents Sea, which is associated with the peculiarities of the hydrodynamic regime. Over time, it became clear that there are no endemics in the White Sea, all of them are either reduced to synonyms, or are still found in other seas.
The water area is of great transport importance, as a result of which the ecological condition of certain areas of the water area is deteriorating, especially associated with the transportation of petroleum products and chemical raw materials.
Kara Sea
The Kara Sea is the coldest sea washing the shores of Russia (Fig. 41). It is limited to the coast of Eurasia in the south and the islands: Novaya Zemlya, Franz Josef Land, Severnaya Zemlya, Heiberg. The sea is located on the shelf, where depths range from 50 to 100 m. In shallow water, sandy soil dominates, and the gutters are covered with silt.The Kara Sea is characterized by a marine polar climate, which is due to its geographical location. Weather conditions are variable and storms are frequent. This area recorded the lowest temperature that can be set at sea: -45-50 °C. In summer, an area of high pressure forms over the water area, the air warms up from +2-+6 °C in the north and west to + 18-+20 °C on the coast. However, even in summer there may be snow.
The salinity of the sea near the coasts is about 34%o, which is associated with good mixing and uniform temperatures; in the inland areas the salinity increases to 35%o. At river mouths, especially when ice melts, salinity decreases sharply and the water becomes closer to fresh.
The circulation of water in the Kara Sea is complex, which is associated with the formation of cyclonic water cycles and the river flow of Siberian rivers. The tides are semidiurnal and their height does not exceed 80 cm.
The sea is covered with ice almost all year round. In some areas, multi-year ice is found, up to 4 m thick. Fast ice forms along the Zeregovaya line, the formation of which begins in September.
The Kara Sea contains predominantly Arctic ecosystems; however, during the period of global warming, accumulations of boreal and boreal-Arctic species are observed. The greatest biodiversity is confined to upwelling zones, the edge of sea ice, river estuaries, areas of underwater hydrothermal fluids and the tops of the seafloor relief. Commercial concentrations of cod, flounder, black halibut, and whitefish have been recorded in the water area. Among the environmentally unfavorable factors leading to disruption of ecosystems, it should be noted pollution with heavy metals and petroleum products. Also in the water area there are sarcophagi of radioactive reactors, the burial of which was carried out in the second half of the 20th century.
Arctic omul is a semi-anadromous fish and an important commercial species. It spawns in the Yenisei River, and feeds in the coastal zone of the Kara Sea. According to one hypothesis, the omul could reach Lake Baikal, the cause of which is a glacier. Because of the glacier, the omul was unable to return to its “historical homeland”, giving rise to a branch of the Baikal omul.
Laptev sea
The Laptev Sea is a marginal sea of the Arctic Ocean, located between the Taimyr Peninsula and the Severnaya Zemlya islands in the west and the New Siberian Islands in the east (Fig. 42). This is one of the deepest northern seas, the greatest depth is 3385 m. The coast is heavily indented. The southern part of the sea is shallow with depths of up to 50 m, bottom sediments are represented by sand, silt with admixtures of pebbles and boulders. The northern part is a deep-sea basin, the bottom of which is covered with silt.The Laptev Sea is one of the harshest seas in the Arctic Ocean. Climatic conditions are close to continental. In winter, an area of high atmospheric pressure dominates, which causes low air temperatures (-26-29 °C) and slight cloudiness. In summer, the area of high pressure gives way to low pressure, and the air temperature increases, reaching its highest point in August at +1-+5 °C, but in enclosed spaces the temperature can reach higher values. For example, in Tiksi Bay a temperature of +32.5 °C was recorded.
Water salinity varies from 15%o in the south to 28%o in the north. Near the mouth areas, salinity does not exceed 10%. Salinity increases with depth, reaching 33%. Surface currents form a cyclonic gyre. Tides are semidiurnal, up to 0.5 m high.
The cold climate causes active development of ice in the water area, which can persist throughout the year. Hundreds of kilometers of shallow water are occupied by fast ice, and floating ice and icebergs are found in open waters.
The ecosystems of the Laptev Sea are not distinguished by species diversity, which is associated with extreme natural conditions. The ichthyofauna has only 37 species, and the bottom fauna is about 500. Fishing is developed mainly along the coasts and at river mouths. However, the Laptev Sea is of great transport importance. The port of Tiksi is of greatest importance. The ecological state of some areas of the sea is assessed as catastrophic. In coastal waters, there is an increased content of phenol, petroleum products, and organic substances. Most of the pollution comes from river waters.
From time immemorial, the Laptev Sea has been the main “workshop” for ice production in the Arctic. An international group of researchers within the Polynya project studied the climate in the water area for several years, as a result of which it was noted that since 2002, the water temperature has increased by 2 °C, which will inevitably affect its ecological state.
East-Siberian Sea
The East Siberian Sea is a marginal sea of the Arctic Ocean. It is located between the New Siberian Islands and Wrangel Island (see Fig. 42). The coasts are flat, slightly indented, and in some places there are sandy and silty dry areas. In the eastern part beyond the mouth of the Kolyma there are rocky cliffs. The sea is shallow, the greatest depth is 358 m. The northern border coincides with the edge of the continental shallows.The bottom topography is leveled and has a slight slope from southwest to northeast. Two underwater trenches stand out in the relief, which are presumably former river valleys. The soil is represented by silt, pebbles, and boulders.
The proximity to the North Pole determines the severity of the climate, which should be classified as polar marine. It is also worth noting the influence on the climate of the Atlantic and Pacific oceans, from where cyclonic air masses come. The air temperature in January over the region is -28-30 °C, the weather is clear and calm. In summer, an area of high pressure forms over the sea, and low pressure over the adjacent land, which leads to the emergence of strong winds, the speed of which is maximum towards the end of summer, when the western part of the water area turns into a zone of strong storms, while the temperature does not exceed +2-+3 °C . This section of the Northern Sea Route becomes the most dangerous during this period.
The salinity of water near river mouths is no more than 5%o, increasing towards the northern outskirts to 30%o. With depth, salinity increases to 32%.
Even in summer the sea is not free of ice. They drift in a northwesterly direction, obeying the circulation of water masses. As the activity of the cyclonic gyre intensifies, ice penetrates into the water area from the northern borders. The tides in the East Siberian Sea are regular, semi-diurnal. They are most clearly expressed in the northwest and north; near the southern coasts the tide height is insignificant, up to 25 cm.
The combination of natural and climatic conditions influenced the formation of ecosystems in the East Siberian Sea. Biodiversity is much lower compared to other northern seas. In the estuary areas there are schools of white fish, polar cod, Arctic char, whitefish, and grayling. There are also marine mammals: walruses, seals, polar bears. Cold-loving brackish-water forms are common in the central parts.
East Siberian cod (ninefin) (Fig. 43) lives near the coast in brackish waters and enters river mouths. The biology of the species has hardly been studied. Spawning occurs in summer in warm coastal waters. It is an object of fishing.
Chukchi Sea
The Chukchi Sea is located between the Chukotka and Alaska peninsulas (Fig. 44). The Long Strait connects it with the East Siberian Sea, in the area of Cape Barrow it borders on the Beaufort Sea, and the Bering Strait connects it with the Bering Sea. The International Date Line runs through the Chukchi Sea. More than 50% of the sea area is occupied by depths of up to 50 m. There are shallows with depths of up to 13 m. The bottom relief is complicated by two underwater canyons with depths from 90 to 160 m. The coast is characterized by slight ruggedness. The soils are represented by loose deposits of sand, silt, and gravel. The climate of the sea is greatly influenced by the proximity of the North Pole and the Pacific Ocean. In summer, anticyclonic circulation occurs. The sea is characterized by high storm activity.
The circulation of water masses is determined by the interaction of cold Arctic and warm Pacific waters. A cold current passes along the Eurasian coast, carrying water from the East Siberian Sea. The warm Alaskan Current enters the Chukchi Sea through the Bering Strait, heading towards the shores of the Alaska Peninsula. Tides are semidiurnal. The salinity of the sea varies from west to east from 28 to 32%. Salinity decreases near melting ice edges and river mouths.
The sea is covered with ice for most of the year. In the southern part of the sea, clearing of ice occurs during 2-3 warm months. However, floating ice brings it to the coast of Chukotka from the East Siberian Sea. The north is covered with multi-year ice more than 2 m thick.
The penetration of warm waters of the Pacific Ocean is the main reason for a slight increase in the species diversity of the Chukchi Sea. Boreal species are joining the typical Arctic species. 946 species live here. There are navaga, grayling, char, and polar cod. The most common marine mammals are polar bears, walruses, and whales. The location at a sufficient distance from industrial centers determines the absence of serious changes in marine ecosystems. The ecological picture of the water area is negatively affected by the supply of petroleum products along the Northern Sea Route, as well as by waters containing aerosol materials coming from the coast of North America.
The Chukchi Sea serves as a link between the ports of the Far East, the mouths of Siberian rivers and the European part of Russia, as well as between the Pacific ports of Canada and the USA and the mouth of the Mackenzie River.