East Siberian Sea: description, resources and problems. East Siberian Sea Physical and geographical position of the East Siberian Sea

This is an arctic sea included in. Located near Eastern Siberia. Fully located above the Arctic Circle. Its borders are almost everywhere conditional lines. Only in the south is the sea bounded by the mainland. It connects through the straits with the Chukchi Sea.
Sea area - 913 thousand sq. Km. The depth is shallow and averages 54 meters, the maximum is 915 meters.
The shores are indented by bays (Kolyma Bay, Omulakhskaya and Chaunskaya bays). The western coast of the mainland is gentle, the eastern one is mountainous with cliffs.
The few islands form groups: New Siberian Islands, Medvezhye, Shalaurov Islands. Some islands are crumbling as they are made entirely of sand and ice.
Rivers flowing into the sea: Lapcha, Khroma, Kolyma, Alazeya, etc.
This sea is completely located on the shelf, as a result of which its bottom is a plain, gradually lowering to the north. There are no significant hills or depressions, the depth almost everywhere does not exceed fifty meters.
Climate in the East Siberian Sea arctic, influenced by the air masses of two oceans: and. Winter is characterized by clear weather with temperatures down to -30 degrees. Summer is gloomy, cold and windy, rain and sleet often fall. In winter, almost the entire sea is covered with ice; in summer, the coastal part in the west is freed from ice, and in the east, floating ice floes are characteristic.
In the expanses of water East Siberian Sea whitefish are found (such as omul, muksun). Mammals are represented by seals, walruses, polar bears.
The famous Northern Sea Route runs along the East Siberian Sea. The most important ports are Pavek and Ambarchik.

The Greenland Sea is one of the marginal seas of the Arctic Ocean.
The sea, with an area of ​​1205 thousand square kilometers, is located between the Bear Islands, Svalbard, Iceland, Greenland and Jan Mayen. The average depth of this sea is 1641 m, while the maximum reaches 5527 m.
The Greenland Sea bed is a large basin, which is bounded in the east by the Mona and Knipovich ranges, and in the south by the Greenland-Icelandic rapids.
Greenlandic climate [...]

Off the coast of the East Siberian Sea

The East Siberian Sea is located between the Novosibirsk Islands and about. Wrangel. Its western border is the eastern border of the Laptev Sea, it runs from the point of intersection of the meridian of the northern tip of about. Kotelny with the edge of the continental shelf (79 ° N, 139 ° E) to the northern tip of this island (Cape Anisiy), then along the eastern shores of the New Siberian Islands to Cape Svyatoy Nos (Dmitry Laptev Strait). The northern border runs along the edge of the continental shelf from the point with coordinates 79 ° N, 139 ° E. to the point with coordinates 76 ° N, 180 ° E, and the eastern border - from the point with these coordinates along the meridian 180 ° to the island. Wrangel, then along its north-western coast to Cape Blossom and further to Cape Yakan on the mainland. The southern border runs along the mainland coast from Cape Yakan to Cape Svyatoy Nos.

The East Siberian Sea belongs to the type of continental marginal seas. Its area is 913 thousand km 2, volume - 49 thousand km 3, average depth - 54 m, maximum depth - 915 m, i.e. this sea lies entirely on the continental shelf.

The coastline of the East Siberian Sea forms rather large bends, in places extending into the land, in places protruding into the sea, but there are also areas with a flat coastline. Small convolutions are usually confined to the mouths of small rivers.

The landscapes of the western part of the East Siberian Sea coast differ sharply from the eastern one. In the area from the New Siberian Islands to the mouth of the Kolyma, the shores are very low and monotonous. The swampy tundra approaches the sea here. East of the mouth of the Kolyma, beyond Cape Bolshoy Baranov, the coast becomes mountainous. From the mouth of the Kolyma to about. Aion, low hills approach the water, steeply breaking off in places. Chaunskaya Bay is framed by low, but steep, smooth banks. Different in relief and structure of the sea coast in different areas refers to different morphological types of coast.

East-Siberian Sea

Climate

Located in high latitudes, the East Siberian Sea is in the atmospheric impact zone of the Atlantic and Pacific oceans. Cyclones of Atlantic origin penetrate into the western part of the sea (although rarely), while cyclones of the Pacific origin penetrate into the eastern regions. The climate of the East Siberian Sea is polar sea, but with signs of continentality.

In winter, the main influence on the sea is exerted by the spur of the Siberian maximum, which goes to the coast, and the crest of the polar anticyclone is weakly expressed. In this regard, southwestern and southern winds prevail over the sea at a speed of 6-7 m / s. They bring cold air from the continent, so the average monthly air temperature in January is about –28-30 °. In winter, the weather is calm, clear, which on some days is interrupted by cyclonic invasions. Atlantic cyclones in the west of the sea cause increased wind and some warming, while Pacific cyclones, which have cold continental air in their rear, only increase wind speed, cloudiness and cause blizzards in the southeastern part of the sea. On mountainous areas of the coast, the formation of a local wind - a phene - is associated with the passage of Pacific cyclones. It usually reaches storm strength, causing a slight increase in temperature and a decrease in air humidity.

In summer, the pressure over the mainland Asia is lowered, and over the sea it is increased, therefore, the winds of the northern points prevail. At the beginning of the season they are very weak, but during the summer their speed gradually increases, reaching an average of 6-7 m / s. By the end of summer, the western part of the East Siberian Sea becomes one of the most turbulent sections of the Northern Sea Route. The wind often blows at a speed of 10-15 m / s. The increase in the wind here is associated with hair dryers. The southeastern part of the sea is much calmer. Sustainable northerly and northeasterly winds cause low air temperatures. The average July temperature is 0-1 ° in the north of the sea and 2-3 ° in the coastal regions. In summer, over the East Siberian Sea is mostly cloudy weather with light drizzling rain, sometimes sleet.

In autumn, there are almost no returns of heat, which is explained by the remoteness of the sea from the oceanic centers of atmospheric action and their weak influence on atmospheric processes. Relatively cold summers throughout the sea, stormy weather at the end of summer and especially in autumn in the marginal regions of the sea and calmness in the central part of it are characteristic climatic features of the sea.

The continental runoff into the East Siberian Sea is relatively small - about 250 km 3 / year, which is only 10% of the total river runoff into all Arctic seas. The largest of the flowing rivers - the Kolyma - gives about 130 km 3 of water per year, and the second largest river - the Indigirka - 60 km 3 of water / year. All other rivers pour about 350 km 3 of water into the sea during the same time. All river water flows into the southern part of the sea, with about 90% of the flow, as in other Arctic seas, during the summer months.

With a very large size of the East Siberian Sea, coastal runoff does not significantly affect its general hydrological regime, but only determines some hydrological features of coastal areas in summer. High latitudes, free communication with the Central Arctic Basin, high ice coverage and low river runoff determine the main features of the hydrological conditions of the East Siberian Sea.

Water temperature and salinity

Types of vertical distribution of temperature (1), salinity (2) and density (3) of water in the Arctic seas

Due to the shallowness and the absence of deep trenches extending beyond the northern limits of the East Siberian Sea, the overwhelming part of its space from surface to bottom is occupied by surface Arctic waters. Only in relatively limited estuarine areas is a kind of water formed as a result of mixing river and sea waters. It is characterized by high temperatures and low salinity.

The surface water temperature in all seasons generally decreases from south to north. In winter, it is close to the freezing point and near river mouths is –0.2–0.6 °, and at the northern borders of the sea –1.7–1.8 °. In summer, the distribution of surface temperature is due to ice conditions. The water temperature in bays and bays reaches 7-8 °, in open, ice-free regions 2-3 °, and at the edge of the ice it is close to 0 °.

The change in water temperature with depth in winter and spring is little noticeable. Only near the mouths of large rivers does it decrease to –0.5 ° in the under-ice horizons and to –1.5 ° at the bottom. In summer, in ice-free areas, the water temperature slightly decreases from surface to bottom in the coastal zone in the west of the sea. In its eastern part, the surface temperature is observed in a layer of 3-5 m, from where it drops sharply to horizons of 5-7 m and then gradually decreases to the bottom. In the zones of influence of coastal runoff, the uniform temperature covers a layer up to 7-10 m, between 10-20 m horizons it sharply, and then gradually decreases to the bottom. The shallow, slightly warmed East Siberian Sea is one of the coldest Arctic seas.

Salinity at the surface generally increases from southwest to northeast. In winter and spring, it is 4-5 ‰ near the mouths of the Kolyma and Indigirka, reaches 24-26 ‰ near the Bear Islands, increases to 28-30 ‰ in the central regions of the sea and rises to 31-32 ‰ on its northern outskirts. In summer, as a result of the influx of river waters and melting of ice, the surface salinity decreases to 18-22 ‰ in the coastal zone, 20-22 ‰ near the Medvezhye Islands, to 24-26 ‰ in the north, at the edge of melting ice.

In winter, over most of the sea, salinity slightly increases from surface to bottom. Only in the northwestern region, where ocean waters penetrate from the north, does salinity increase from 23 ‰ in the upper layer 10-15 m thick to 30 ‰ at the bottom. Near the estuarine areas, the upper desalinated layer up to horizons of 10-15 m is underlain by more saline waters. From the end of spring and during the summer, a desalinated layer 20-25 m thick forms on ice-free spaces, under which salinity increases with depth. Consequently, in shallow areas (down to depths of 10-20 and even up to 25 m), freshening covers the entire water column. In deeper areas in the north and east of the sea, at levels of 5-10 m, and in some places 10-15 m, salinity increases sharply, and then gradually and slightly rises to the bottom.

In the autumn-winter season, the water density is higher than in the spring and summer. The density is higher in the north and east than in the west of the sea, where desalinated waters from the Laptev Sea penetrate. However, these differences are small. Typically, density increases with depth. Its vertical distribution is similar to the course of salinity.

Different degrees of water stratification create unequal conditions for the development of mixing in different regions of the East Siberian Sea. In relatively weakly stratified and ice-free areas, strong winds in summer mix the water up to 20–25 m horizons. Consequently, in areas limited by a depth of 25 m, wind mixing extends to the bottom. In places of sharp stratification of waters in terms of density, wind mixing penetrates only up to horizons of 10-15 m, where it is limited by significant vertical density gradients.

Autumn-winter convection in the East Siberian Sea at depths of 40-50 m, which occupies more than 70% of its entire area, penetrates to the bottom. Towards the end of the cold season, the winter vertical circulation extends to the level of 70-80 m, where it is limited by the high vertical stability of the waters.

Bottom relief

The underwater relief of the shelf forming the sea bed, in general terms, is a plain, very slightly inclined from the southwest to the northeast. The seabed has no noticeable depressions and elevations. Depths up to 20-25 m prevail. To the northeast of the mouths of the Indigirka and Kolyma, shallow trenches are noted on the seabed. It is believed that these are traces of ancient river valleys, flooded with the sea. The area of ​​shallow depths in the western part of the sea forms the Novosibirsk shoal. The greatest depths are concentrated in the northeastern part of the sea. A noticeable increase in depth occurs in the horizon from 100 to 200 m.

Topography of the bottom and current of the East Siberian Sea

Currents

Constant currents on the surface of the East Siberian Sea form a weakly expressed cyclonic circulation. A steady transfer of water from west to east can be traced along the mainland coast. Near Cape Billing, part of the waters is directed to the north and northwest and is carried out to the northern margins of the sea, where it is included in the flows going to the west. In different synoptic situations, the movement of waters also changes. Part of the waters from the East Siberian Sea through the Long Strait is carried out into the Chukchi Sea. Constant currents are often disturbed by wind currents, which are often stronger than constant currents. The influence of tidal currents is relatively small.

Regular semi-daily tides are observed in the East Siberian Sea. They are caused by a tidal wave that enters the sea from the north and moves towards the coast of the mainland. Its front will stretch from the north-north-west to the east-south-east from the New Siberian Islands to about. Wrangel.

The tides are most pronounced in the north and northwest. They weaken as we move south, as ocean tidal waves are largely damped in the vast shallow waters. Thus, in the area from Indigirka to Cape Shelagsky, tidal level fluctuations are almost invisible. To the west and east of this area, the tide is also small - 5-7 cm. At the mouth of the Indigirka, the configuration of the shores and bottom relief contribute to an increase in tides up to 20-25 cm. Level changes caused by meteorological reasons are much more developed on the mainland coast.

The annual variation of the level is characterized by its highest position in June-July, when there is an abundant inflow of river waters. A decrease in the continental runoff in August leads to a decrease in the level by 50-70 cm. As a result of the prevalence of surge winds in autumn, in October, the level rises.

In winter, the level decreases and in March - April it reaches its lowest position.

In the summer season, surge phenomena are very pronounced, in which level fluctuations are often 60-70 cm.At the mouth of the Kolyma and in the Dmitry Laptev Strait, they reach the maximum values ​​for the entire sea - 2.5 m.

A quick and abrupt change in level positions is one of the characteristic features of the coastal areas of the sea.

Significant waves develop in ice-free areas of the sea. It is strongest during stormy northwestern and southeastern winds, which have the greatest acceleration over the surface of clear water. The maximum wave heights reach 5 m, usually their height is 3-4 m. Strong waves are observed mainly in late summer - early autumn (September), when the ice edge retreats to the north. The western part of the sea is more stormy than the eastern one. Its central areas are relatively calm.

Ice cover

The East Siberian Sea is the most ice-covered of the seas of the Soviet Arctic. From October-November to June-July, it is completely covered with ice. At this time, the predominance of ice from the Arctic basin to the sea, in contrast to other seas of the Arctic, where ice drift prevails. A characteristic feature of the ice of the East Siberian Sea is the significant development of fast ice in winter. Moreover, it is most widely distributed in the western, shallow-water part of the sea and occupies a narrow coastal strip in the east of the sea. In the west of the sea, the fast ice width reaches 400-500 km. Here it joins the fast ice of the Laptev Sea. In the central regions its width is 250-300 km and to the east of Cape Shelagsky - 30-40 km. The fast ice boundary approximately coincides with the 25 km isobath, which runs 50 km north of the New Siberian Islands, then turns to the southeast, approaching the mainland coast near Cape Shelagsky. By the end of winter, the fast ice thickness reaches 2 m. From west to east, the fast ice thickness decreases. Drifting ice is located behind fast ice. Usually it is one-year and two-year ice with a thickness of 2-3 m. In the very north of the sea, there is a long-term arctic ice. The prevailing southern winds in winter often carry the drifting ice from the northern edge of the fast ice. As a result, significant areas of clean water and young ice appear, forming in the west Novosibirsk and in the east Zavrangel stationary ice holes.

At the beginning of summer, after the breakup and destruction of fast ice, the position of the ice edge is determined by the action of winds and currents. However, ice is always found north of the strip about. Wrangel - New Siberian Islands. In the western part of the sea, on the site of an extensive fast ice, the Novosibirsk ice massif is formed. It consists mainly of first-year ice and is usually destroyed by the end of summer. The overwhelming part of the space in the east of the sea is occupied by the spur of the Aion oceanic ice massif, which largely forms heavy perennial ice. Its southern periphery almost adjoins the coast of the mainland throughout the year, determining the ice situation in the sea.

Economic value

The East Siberian Sea is similar in natural and biological conditions to the Laptev Sea. The relative richness of life is observed in the coastal zone, in the areas where large rivers flow. Animals adapted to life in waters with low salinity are widespread here. In the central regions, cold-loving brackish-water forms are found. Fishing is of purely local importance.

EASTERN SIBERIAN SEA, the marginal sea of ​​the Arctic Ocean off the northeastern coasts of Asia, between the New Siberian Islands and Wrangel Island. In the west it borders on the Laptev Sea, connecting with it by the straits: Dmitry Laptev, Eterikan and Sannikov, in the east - with the Chukchi Sea, with which the Long Strait is connected. The northern border runs along the edge of the continental shelf, approximately along the 200 m isobath (79 ° north latitude). The area is 913 thousand km 2, the volume is 49 thousand km 3. The greatest depth is 915 m.

The coastline is relatively weakly indented. Bays: Chaunskaya Bay, Kolyma Bay, Omulyakhskaya and Khromskaya Bay. Islands: Novosibirsk, Bear, Aion and Shalaurova. Some islands are entirely composed of fossil ice and sand and are subject to intense destruction. Large rivers flow into the sea: Kolyma, Alazeya, Indigirka, Khroma. The coast of the western part of the sea (up to the Kolyma River) is low-lying and composed of permafrost alluvial-marine deposits of the Quaternary age, including lenses of fossil ice. The eastern coast (from the Kolyma River to the Long Strait) is mountainous, in places steep, composed of bedrocks; here the denudation type of banks is developed.

Topography and geological structure of the bottom. The East Siberian Sea is located mainly within the shelf, 72% of its bottom area is up to 50 m deep. The shelf is located within the North American lithospheric plate. The underwater relief of the shelf, which forms the sea bed, is a plain, slightly inclined from the southwest to the northeast. The bottom of the western part of the sea is a flat, shallow-water plain, where the Novosibirsk shoal is located. In the southern part, shallow troughs are noted - traces of ancient river valleys of preglacial and glacial times. The greatest depths are in the northeastern part. The seabed is composed of folded complexes (Mesozoic in the south and, possibly, more ancient in the north), dissected by Late Mesozoic riftogenic structures and overlain by a thin cover of Cenozoic sediments. Modern bottom sediments are mainly composed of sandy silt containing crushed boulders and pebbles brought by ice.

Climate... The climate of the East Siberian Sea is arctic. In winter, under the influence of the Siberian maximum, cold southwestern and southern winds prevail over the sea. Average air temperatures in February are from -28 to -30 ° С (minimum -50 ° С); in July in the southern part from 3 to 7 ° С, in the northern - from 0 to 2 ° С. In summer, the weather over the East Siberian Sea is mostly cloudy with light drizzling rain, sometimes sleet; northerly winds prevail. In autumn, on the coast, the speed of northwestern and northeasterly winds increases to 20-25 m / s; far from the coast, the force of storm winds reaches 40-45 m / s, hair dryers contribute to the strengthening of the wind. There are 100-200 mm of precipitation per year.

Hydrological regime... The continental runoff into the East Siberian Sea is relatively small and amounts to about 250 km 3 / year, of which the Kolyma runoff is 123 km 3 / year, and the Indigirka runoff is 58.3 km 3 / year. All river runoff enters the southern part of the sea, 90% - in the summer. The main part of the East Siberian Sea is occupied by surface Arctic waters. In the estuarine areas, waters formed as a result of mixing of river and sea water are widespread. In winter, near river mouths, the surface water temperature varies from -0.2 to -0.6 ° C, and at the northern border of the sea from -1.7 to -1.8 ° C. In summer, the distribution of surface water temperature is due to ice conditions. In bays and bays 7-8 ° С, in ice-free regions 2-3 ° С, and at the ice edge about 0 ° С. The salinity of surface waters increases from the southwest to the northeast from 10-15 ‰ near river mouths to 30-32 ‰ at the ice edge. The East Siberian Sea is covered with ice for most of the year. In the eastern part, floating ice remains off the coast even in summer. A characteristic feature of ice is the development of fast ice, which is most widely distributed in the western shallow part of the sea, where its width reaches 600-700 km; in the central regions - 250-300 km, to the east of Cape Shelagsky it occupies a narrow coastal strip of 30-40 km. By the end of summer the fast ice is 2 m thick. Behind the fast ice there are drifting ice - annual and biennial, 2-3 m thick; ice drift depends on the circulation of air masses. Perennial arctic ice is found in the north. In the western part of the sea, between fast ice and drifting ice, there is a long-term polynya along which the Northern Sea Route passes. The existence of a polynya in winter is associated with squeeze winds and tidal currents. In the eastern part, the fast ice joins the drifting ice and the ice hole closes. The currents form a cyclonic circulation; in the northern part, the current is directed to the west, in the southern - to the east. The tides are regular semidiurnal, the amplitude of level fluctuations is up to 25 cm.

Research history... The beginning of the development of the East Siberian Sea by Russian sailors dates back to the 17th century, when navigations were made along the coast between river mouths. In 1648 S. Dezhnev and F. Popov sailed from the Kolyma River to the Bering Strait and to the Anadyr River. In the 18th century, the first works were carried out to describe the coast and islands of the East Siberian Sea, maps were compiled. Particularly significant work was done by the participants of the Great Northern Expedition (1733-43). The clarification of the coastal contours was carried out by the Ust-Yanskaya and Kolyma expeditions under the leadership of P.F. Anzhu (1822) and F.P. In the 20th century, maps were refined by K.A. Vollosovich (1909) and G. Ya. Sedov (1909), as well as during the work of a hydrographic expedition in the Arctic Ocean (1911-14). After 1932, when the icebreaker Sibiryakov sailed along the Northern Sea Route in one navigation, regular voyages of ships were made to the East Siberian Sea.

Economic use... The coastal zone is characterized as an area with low economic activity. The flora and fauna of the East Siberian Sea is poor due to the harsh ice conditions. But in areas adjacent to river mouths, omul, whitefish, grayling, polar smelt, navaga, polar cod and flounder, salmon - char and nelma are found. Among mammals there are walrus, seals, polar bear; from birds - guillemots, seagulls, cormorants. Fishing is of local importance. The Northern Sea Route runs along the East Siberian Sea; the main port of Pevek (Chaunskaya Bay). The East Siberian Sea is a promising oil and gas region, the development of which is difficult due to the harsh natural conditions.

Ecological state. In general, the ecological situation in the East Siberian Sea is characterized as favorable due to the poor economic use of this region. The shallow-water shelf is slightly polluted, subject to the influence of river runoff, and as a result of thermal abrasion destruction of the banks, greenhouse gases (carbon dioxide and methane) enter the atmosphere.

Lit .: Zalogin B.S., Kosarev A.N. Morya. M., 1999.