The East Siberian Sea is why it is so named. East Siberian Sea: description, resources and challenges

It is not so easy to find the East Siberian Sea on the map at once. The fact is that its borders are conditional and only in some places are limited by land. In the western part, the limit is Kotelny Island and the Laptev Sea; in the north - the edge of the continental shelf; in the east, the border is the meridian, passing through in the southern part of the sea is limited by the mainland.

Dimensions and depth

The maximum depth of the East Siberian Sea is 915 meters, and the average value of this indicator is 54 meters. In other words, this body of water is completely within the continental shelf. Its total area is 913 thousand m 2. As for the volume, it is approximately 49 thousand cubic kilometers.

The shores

The East Siberian Sea has a coastline that is very different in its relief in the eastern and western parts. In its landscapes, there are quite large bends, which in some places protrude deeply, and in others they go far to land. In addition to them, straight sections are quite common. Small meanders are usually found at river mouths. In the islands, the coastline is monotonous and low-lying. A similar situation is also typical for the mouth. In the southern part of the Long Strait, the shores are covered with a mixture of pebbles and sand, which separate the chains of lagoons.

It should be noted that the size of the depths in the coastal regions is significantly influenced by the amount of precipitation carried by the rivers. Under their influence, bars are also formed - alluvial shoals. Among other things, river runoff increases the temperature of the water, resulting in thermal abrasion in the estuarine areas. Its speed is from one to fifteen meters per year.

Bottom structure

The sea bed is formed by a shelf, the relief of which is mostly flat. It is slightly tilted towards the north eastward... On the western side is the so-called "area of ​​shallow depths". She also formed the Novosibirsk shoal. As for the deeper places, they are typical for the northeastern region. A significant part of the bottom is covered by a thin sedimentary cover. Many archipelagos and islands of the East Siberian Sea (of which there are not so many here) were formed precisely due to this foundation. These include Ayon, Medvezhy, and the New Siberian Islands. Various aeromagnetic images show that the bottom sediments of the shelf mainly include sandy silt, pebbles and crushed boulders. There is every reason to believe that some of them are fragments of some islands that were carried by ice throughout the territory.

Climate

Many are interested in the question: "East Siberian Sea - what ocean is the water area?" Despite the fact that the reservoir belongs to the basin of the Arctic Ocean, it is also subject to atmospheric influences from the Pacific and Atlantic. The climate here is arctic. With him in winter time the average temperature is -30 degrees, and in summer - about +2. For most of the year, the sea surface is covered with ice. In the eastern region, often floating ice are located near the coast even in the summer months.

In winter, the East Siberian Sea is under the influence of southern and south-western winds, the speed of which is about seven meters per second. They bring cold air from the continent. In summer, the pressure rises here, in connection with which the northern rumba begin to prevail among the winds. They are rather weak at the beginning of the season, but closer to the middle of the season, their power only increases, and the speed reaches 15 meters per second. At this time, the weather is mostly cloudy with sleet or drizzling rain. Due to the fact that this reservoir is quite remote from the centers, which are influenced by the atmosphere, in the fall, heat returns almost never occur here.

Water temperature and salinity

Throughout the year, the surface temperature of sea water decreases from south to north. In the winter season, in the areas of river estuaries, it is about -0.5 degrees, while in the northern borders - about -1.8 degrees. In the summer, everything depends on the ice conditions. At this time, in the bays the temperature reaches +8 degrees, in ice-free areas it is about +3 degrees, and at the edge of the ice it is on average zero degrees. In spring and winter, the change in water temperature with diving is insignificant. In summer, the water gets colder closer to the bottom, especially in the western region.

The salinity level of water in the sea changes in a northeast direction. In spring and winter, it ranges from 4 ppm near the Indigirka and Kolyma rivers to 32 ppm in the central and northern regions. In summer, ice melting and a significant influx of river waters lead to the fact that this figure decreases. It should also be noted that the salinity level does not increase much closer to the seabed. As for such an indicator, it is the highest in the autumn-winter period. In addition, it grows as you go deeper.

Hydrology

The East Siberian Sea is not very high compared to other representatives of the Arctic Ocean basin. The largest of the rivers that flows into it is the Kolyma. Its runoff is approximately 132 cubic kilometers per year. The second in this value is the Indigirka River, which over the same period brings twice less water. At the same time, even in conditions of a relatively large size, the coastal runoff does not significantly affect the overall hydrological situation. At present, the system of currents in this sea is not very thoroughly studied either. It is safe to say that the general water circulation here is cyclonic in nature. As for precipitation, their average annual value is in the range from 100 to 200 millimeters. Due to the fact that there are no deep trenches here, and a significant area is shallow water, Arctic surface waters take up a lot of space.

Tides

The sea is characterized by semi-daily regular tides, which are caused by a wave moving towards the continental coast from the north. They are best expressed in the northwestern and northern regions, while weakening in the southern direction. This can be explained by the fact that the tidal wave is damped in shallow water. For example, while in the area from Cape Shelagsky to the level fluctuations are almost imperceptible, at its mouth the relief and coastal configuration lead to an increase in tides by about 25 centimeters. The highest water level is typical for June-July, because at this time the largest river tributary. In winter, the level gradually decreases and in March reaches its minimum value.

Flora and fauna

The resources of the East Siberian Sea, namely flora and fauna, are rather poor. First of all, this is due to the harsh conditions created here by nature itself, therefore, only those that turned out to be the most resistant to low temperatures took root here. In the regions of river estuaries, rather large schools of white fish are often found. Here you can find omul, grayling, whitefish, navaga, polar flounder, cod and others. Representatives of mammals here are polar bears, seals and walruses. As for the birds, among them are cormorants, sea gulls and guillemots. It is possible that a polar shark, reaching six meters in length, also lives in local waters, but clear evidence of this has not yet been found.

Sea problems

The problems of the East Siberian Sea are in many ways similar to the problems of other northern seas, for example, the Barents, Kara, White and others. In this case, we are talking primarily about the environmental component. Despite the fact that the water here is relatively clean, the Europeans have been destroying local biological resources, especially whales, for several years. Over time, this led to a significant reduction in their number and even to the extinction of some species. One cannot fail to note one more problem, which has recently acquired a global character. It is about which the local fauna suffers. Among other things, human activities related to the development of oil and gas fields also negatively affect the state of the water area.

Economic situation

In 1935, regular voyages of ships began on the so-called laid through the East Siberian Sea. At the same time, one cannot but focus on the fact that the navigation season here lasts only three months - it starts at the end of July and ends at the beginning of November. In this case, navigation is allowed only at this time and in the coastal strip.

Due to the harsh climate in the East Siberian Sea, its own life has developed. Only the most persistent representatives of flora and fauna live here, which have adapted to low temperatures. Its waters contain the same microscopic phytoalgae and organisms that are found in the neighboring Laptev Sea. Mostly diatoms are found, from time to time red and brown algae appear - in the coastal region of the western part of the sea. Compared to neighboring seas, there are few bottom dwellers here. After all, not every species can survive in low temperatures. Therefore, only some species of crustaceans, valvates, echinoderms, and coelenterates are found.

Mammals of the East Siberian Sea include seals, beluga whales, cetaceans and walruses. Along with all coastal zones of the northern seas, walruses are harvested on its territory, but only for needs local population... Indeed, since 1956, walruses have been under state protection. The islands are also home to polar bear, which is a semi-marine mammal. For the sake of food, smaller predators come to the shores of the East Siberian Sea, we are talking about sea otters and arctic foxes.

There is no information that sharks live in the waters of this sea. Possibly, here you can find a polar shark - an inhabitant of the Arctic waters. Such a six-meter shark almost never comes to the sea surface. It feeds on the smallest organisms, animal remains and small fish. The polar shark is lazy, like many other Arctic giants, so you should not expect an attack on active living creatures. Scientists say that bathers of this harsh sea need not be afraid of the teeth of man-eating sharks. Therefore, you can often meet travelers here.

November 26, 2006

1. NORTHERN ICE OCEAN …………………………………………… .3

2. EASTERN SIBERIAN SEA ……………………………………………… 4

2.1. Shores …………………………………………………………………………… 5

2.2. Bottom structure …………………………………………………………………… 6

2.3. Typical climate ……………………………………………………… 7

2.4. Hydrological regime ………………………………………………… ..9

2.5. Ice regime …………………………………………………………… 13

2.6. Biology ……………………………………………………………………… 14

REFERENCES ………………………………………………………… .15

1. NORTHERN ICE OCEAN.

The Arctic Ocean is small compared to other parts of the World Ocean: its area is about 13.1 million km 2 (3.6% of the area of ​​the World Ocean). Nevertheless, the practical and scientific significance of the research of the Arctic Ocean is very great. The shortest, but also one of the most difficult in terms of ice conditions sea route runs through it. In addition, it serves as the only sea route to supply the booming industry of Siberia.

Due to its remoteness, harsh climate and persistent ice cover, the Arctic Ocean is the least explored of the oceans. By the end of the 19th century. almost all of its coastline was mapped in some detail, but much of the ocean itself remained unexplored. The northern tip of Greenland and the group of islands in the Canadian Arctic Archipelago have been completely unexplored. Geographers did not have a single point of view regarding the distribution of land and sea. Some scientists, including the German geographer Petermann, believed that Greenland stretched across the North Pole to Wrangel Land (now Wrangel Island); others believed that the central polar region was composed of numerous islands separated by shallow water areas.

During the expedition on the ship "Jeannette" (1879-1881) it was found that Fr. Wrangel is not adjacent to Greenland. In 1893-1896. Nansen's ship "Fram" drifted with long-term ice across the Arctic basin (A. b.) from the Novosibirsk Islands to Spitsbergen. Analysis of the data of eleven measurements of depths made during this drift showed - depth A. b. on this site ranges from 3400 to 4000 m. So for the first time it was established that at least part of A. b. occupies a deep-sea depression.

The Arctic Ocean is also interesting from a hydrometeorological point of view. In the North European Basin there is the most powerful center of "isoanomalous overheating" of the atmosphere on Earth due to the heat of the ocean, the influence of which on atmospheric processes and climatic conditions manifests itself up to Lake Baikal. The Arctic Ocean, especially its Arctic basin, plays the role of one of the planetary "sinks" of heat both in the atmosphere and in the ocean.

2. EASTERN 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). Northern border runs along the edge of the continental shelf from a point with coordinates 79 ° N. w., 139 ° E to the point with coordinates 76 ° N. w., 180 ° E and the eastern border - from the point with these coordinates along the meridian 180 ° to about. 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, the volume is 49 thousand km 3, the average depth is 54 m, the greatest depth is 915 m, that is, this sea lies entirely on the continental shelf.

2.1. Shores.

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.

Suspended sediments carried by rivers cause changes in depths in coastal areas and the formation of bars at river mouths. The Indigirka River carries out suspended sediment per year 16.7 million tons, the Kolyma - 8.3 million tons. The liquid runoff of the Kolyma is 132 * 10 3 m 3 / year.

As a result of the warming effect of river waters on the adjacent coastal areas, intense thermal abrasion of the estuarine coastal areas occurs. According to available data, the abrasion rate ranges from 1-5 to 10-15m / year.

Where the coast is formed by bedrocks (the area of ​​Cape Baranov and Cape Shelagsky, West Coast O. Wrangel, etc.), the denudation type of coast is usually developed, since the impact of waves is weakened and the processes of physical weathering prevail. Accumulative shores with wide sand and pebble bars separating the lagoon chains are found on the southern shore of the Long Strait.

2.2. Bottom structure.

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. 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.

Most of the sea floor is covered with a thin sedimentary cover. In the Tertiary period and at the beginning of the Quaternary, the bottom surface was an almost flat plain, composed of alluvium of the ancient river systems of the paleo-Indigirka and paleo-Kolyma, traces of which can still be distinguished on the seabed. Most of the archipelagos and individual islands found in the shelf area are composed of rocks of this basement (Medvezhyi Islands, Rautan, Shalaurova, part of Aion Island, etc.). In the area of ​​the De Long Islands and in the northern part of the sea, there is the so-called Hyperborean platform (according to Shatsky). Aeromagnetic surveys confirm the presence of a solid crystalline basement in this area, covered and bordered by Mesozoic rocks, in places crumpled by folds.

The shelf bottom sediments consist mainly of sandy silt containing crushed boulders and pebbles; some of them are fragments of rocks about. Wrangel or other islands brought by ice.

2.3. Typical 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 snowstorms 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 e 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 speed of northwestern and northeasterly winds often reaches 20-25 m / s. They cause waves up to 4-5 m high. Westerly winds contribute to the formation of a warm current going eastward from the Kolyma region. It is this warm current that clears the Long Strait of ice. Away from the coast, the speed of storm winds often reaches 40-45 m / s.

The sea is covered with ice for most of the year. In its eastern part, floating ice often remains close to the coast even in summer. Observations carried out at high-latitude stations have shown that the direction of ice drift depends on the distribution of atmospheric pressure. In winter, when a high-pressure area develops at the pole, the anticyclonic (clockwise) circulation of water increases, which forces the ice to drift northwestward. Average daily ice drift speed is 3-8 km.

When the polar anticyclone weakens, the area of ​​cyclonic water circulation expands, which prevents the removal of ice from the area and, conversely, favors the influx of perennial ice from high latitudes and the accumulation of ice in the Long Strait.

2.4. Hydrological regime.

The annual precipitation is 100-200 mm, and the river runoff, in contrast to the Kara Sea and the Laptev Sea, is not very large. Several significant rivers flow into the East Siberian Sea, the largest of which is the. Kolyma. Its annual runoff is 132 km 3. The second most important river flow. Indigirka brings 59 km 3 of water. The total continental runoff to the East Siberian Sea is about 250 km 3 / year, which is only 10% of the total river runoff to all Arctic seas. 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.

The system of currents in the East Siberian Sea is poorly studied. The general circulation of sea waters is cyclonic in nature. From the Sannikov and Dmitry Laptev straits, the water moves along the coast to the east. Near about. Wrangel, part of the current turns to the north, continuing its movement counterclockwise, and the other part passes to the east through the strait. Long (between Wrangel Island and the continental coast). The northward current is drawn into the Transarctic Current, turning northwest. Along the eastern shores of the New Siberian Islands, apparently, there is a current directed to the south and closing the cyclonic circulation.

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.

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.

Tides. 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. Fast and abrupt change of level positions - 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.

Water temperature on the surface 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 free otold spaces, 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 on the surface it generally increases from the southwest to the northeast. In winter and spring, it is equal 4 -5 ° / 00 near the mouths of the Kolyma and Indigirka, reaches values ​​of 24-26 ° / 00 near the Bear Islands, increases to 28 -30 ° / 00 in central regions sea ​​and rises to 31-32 ° / 00 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 ° / 00 in the coastal zone, 20-22 ° / 00 near the Medvezhy Islands, to 24 - 26 ° / 00 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 ° / 00 in the upper layer 10-15 m thick to 30 ° / 00 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 spaces, strong winds in summer stir the water up to the horizons of 20-25 m. 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.

2.5. Ice regime

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 clear water and young ice appear, forming Novosibirskaya in the west and Zavrangelevskaya stationary ice-holes in the east.

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, defining ice conditions in the sea.

2.6. Biology.

The flora and fauna of the East Siberian Sea are qualitatively poor in comparison with neighboring seas, mainly due to the harsh ice conditions. However, in the areas of river mouths, in addition to omul, whitefish and grayling, there are large schools of white fish (Coregonidae). There are also found other fish species, which include polar smelt, navaga, polar cod, polar flounder and salmon: Arctic char and nelma. Mammals are represented by walruses, seals and polar bears, birds - guillemots, sea gulls, cormorants. In the central regions, cold-loving brackish-water forms are found. Fishing is of local importance.

BIBLIOGRAPHY:

1. Bogdanov D.V. Oceans and seas on the eve of the XXI century. - M .: Nauka, 1991 .-- 128 p.

2. Sukhovey F.S. Seas of the World Ocean. - L .: Gidrometeoizdat, 1986 .-- 288 p.

3. Oceanographic Encyclopedia.- L .: Gidrometeoizdat, 1974 .-- 632 p.

4. Zalogin B.S., Kosarev A.N. Seas. - M .: Mysl, 1999 .-- 400 p.

5. Nikiforov E.G., Shpeikher A.O. Regularities of the formation of large-scale fluctuations in the hydrological regime of the Arctic Ocean. - L .: Gidrometeoizdat, 1980 .-- 270 p.

The East Siberian Sea belongs to the Arctic Ocean. It is bounded from the west by the Novosibirsk Islands, and from the east by the Wrangel Island. This reservoir is the least studied in comparison with other northern seas. These places are characterized by a cold climate with poor flora and fauna and low salinity of sea water.

Sea currents are slow, the tides reach no more than 25 cm. In summer there are frequent fogs, ice stays almost all year round, it recedes only in August-September. The sea coast was inhabited thousands of years ago by the Chukchi and Yukaghirs, and then by the Evenks and Evens. These peoples were engaged in hunting, fishing and reindeer herding. Later, the Yakuts appeared, and then the Russians.

East Siberian Sea on the map

Geography

The water surface area of ​​the East Siberian Sea is 942 thousand square meters. km. The volume of water reaches 60.7 thousand cubic meters. km. The average depth is 45 meters, and the maximum is 155 meters. The length of the coastline is 3016 km. The western boundary of the reservoir passes through the New Siberian Islands. The northernmost of these is Henrietta Island, a member of the De Long Island group.

The eastern border passes through Wrangel Island and the Long Strait. In the north, from the northernmost point of Wrangel to Henrietta, Jeannette Island and further to the northern point of Kotelny Island. The southern border runs along the coast of the mainland from Cape Svyatoy Nos in the west to Cape Yakan in the east. The reservoir is connected to the Laptev Sea through the Sannikov, Eterikan and Dmitry Laptev straits. And communication with the Chukchi Sea is carried out through the Long Strait.

Rivers and bays

The most important rivers flowing into the reservoir are Indigirka with a length of 1726 km, Kolyma with a length of 2129 km, Chaun with a length of 205 km, Pegtymel with a length of 345 km, Bolshaya Chukochya with a length of 758 km, Alazeya with a length of 1590 km.

On the coast there are such bays as Chaunskaya Bay, Omulakhskaya Bay, Gusinaya Bay, Khromskaya Bay, Kolymskaya Bay. All these bays drain deep into the land. There is also the Kolyma Bay, bordered from the north by the Bear Islands: Krestovsky, Pushkareva, Leontyev, Lysov, Andreeva and Chetyrekhstolbova.

The river runoff is small and amounts to 250 cubic meters. km per year. Of these, the Kolyma River gives 132 cubic meters. km of water. Indigirka dumps 59 cubic meters into the East Siberian Sea. km of water. 90% of the total runoff occurs in the summer. Fresh water is concentrated near the coast due to a weak current and does not significantly affect the hydrology of the reservoir. But there is water exchange with neighboring seas and the Arctic Ocean.

The surface temperature of the water decreases from south to north. In winter, in river deltas, it is -0.2 and -0.6 degrees Celsius. And in the northern part of the sea it drops to -1.8 degrees Celsius. In summer, the water in the bays warms up to 7-8 degrees Celsius, and in the ice-free sea zones it is 2-3 degrees Celsius.

The salinity of surface waters increases from the southwest to the northeast. In the region of river deltas in winter and spring, it is 4-5 ppm. In open waters it reaches 28-30 ppm, and in the north up to 31-32 ppm. In the summer, the salinity decreases by 5% due to the melting of snow.

The annual fluctuation in the level of the East Siberian Sea is 70 cm due to summer river flows. Winds bring storms with waves 3-5 meters high in the western part of the sea region, while in the east it is relatively calm. Storms usually last 1-2 days in summer and 3-5 days in winter.

The ice thickness reaches 2 meters by the end of winter and decreases from west to east. In addition, there are drifting ice floes with a thickness of 2-3 meters. Ice melting begins in May from the Kolyma River delta. And completely the reservoir freezes in October-November.

Climate

The climate is arctic. In winter, southwestern and southern winds blow, carrying cold air from Siberia, so the average temperature in winter is -30 degrees Celsius. The weather is cloudy with storms and blizzards.

In the summer they blow north winds, and the air temperature is 0-1 degrees Celsius on the high seas and 2-3 degrees Celsius on the coast. The sky is cloudy with frequent rains and sleet. The banks are covered with fog, it can last up to 70 days. Annual precipitation is 200 mm.

Flora and fauna are scarce due to the harsh climate. There are many plankton and crustaceans in the water. Ringed seals, bearded seals, walruses, polar bears live in the coastal zones. From birds there are gulls, cormorants. The East Siberian Sea is frequently visited by bowhead and gray whales. Belugas and narwhals are found. Of the fish there are grayling, muksun, wild boil, smelt, Arctic char, Arctic char, navaga, and flounder.

Shipping

Shipping is practiced to transport goods along north coast Russia in the month of August and September. At the same time, navigation is difficult even in summer due to floating ice floes that bring wind to the shores. Fishing and hunting for marine animals is local.

The main port is Pevek with a population of about 5 thousand people. He is the most northern city Russia and is located in the Chaunskaya Bay. Freight turnover seaport is 190 thousand tons with a throughput capacity of 330 thousand tons. There are 3 berths with a length of 500 meters. Transportation of goods is carried out mainly between Pevek and Vladivostok.

The reservoir received its modern name in June 1935 in accordance with the decree of the Soviet government. Prior to that, it was called either the Indigirsky, the Northern, the Kolymsky, the Siberian, or the Arctic Sea.

Already from the name it is clear that this sea is located off the northern coast. Borders East Siberian Sea predominantly conditional lines are, and only in some parts it is limited by land. From the west, the sea border runs along Kotelny and further along the eastern border. The northern border coincides with the edge of the continental shelf. From the east, the sea border runs along the 1800 east longitude meridian to, after - along the northwestern coast of this island to Cape Blossom and Cape Yakan, located on the mainland. From the southern part it is limited coastline mainland (from Cape Yakan to Cape Svyatoy Nos).

Water of this sea well communicate with the waters of the Arctic Ocean, so the East Siberian Sea belongs to the type of continental marginal seas. Within the outlined border, the area of ​​this sea is 913 thousand km2. The volume of water is approximately 49 thousand km 3. The average sea depth is 54 m, the maximum depth is 915 m.

There are very few islands in the waters of the East Siberian Sea. The coastline of the sea has big bends. Thus, in some places the sea pushes the boundaries of the land inland, and in some places the land protrudes into the sea. There are also areas with an almost flat coastline. Small convolutions are formed mainly at river mouths. the western and eastern coasts of the East Siberian Sea are very different. The coast, which washes the sea from to the mouth of the Kolyma, is rather monotonous. Here the sea borders on swampy areas. These places are characterized by low and gentle shores. The coast, located east of Kalyma, has a more varied landscape, mainly mountains prevail here. Until the island of Ayon, the sea is bordered by small hills, which sometimes have steep slopes. There are low but steep banks in the Chaunskaya Bay area.

The underwater relief of the space occupied by the East Siberian Sea represents. This plain has a slight slope from southwest to northeast. The bottom of the sea is mostly flat, without significant depressions and elevations. Most of the water spaces of the East Siberian Sea have a depth of up to 20 - 25 m. The deepest are located at the bottom of the sea in the northeastern part of the mouths of the Indigira and Kolyma rivers. There is an assumption that these trenches were formerly the regions of river valleys. But later, these rivers were flooded with the sea. The western part of the sea is characterized by a shallow depth; this area is called the Novosibirsk shoal. In the northeast of the sea there are quite deep places... But even here the depth does not exceed 100 m.

East-Siberian Sea

The East Siberian Sea is located in high latitudes, not far from permanent ice... Also, the sea is bordered by a wide part of the mainland. In connection with this location, the East Siberian Sea has a distinctive feature: the sea is under the influence of the Atlantic and. The western part of the sea is sometimes visited by cyclones formed above. The eastern regions of the sea appear to be accessible to the Pacific origin. Thus, the climate of the East Siberian Sea can be characterized as a polar sea, which is greatly influenced by the continent. The peculiarity of the continental climate is significantly manifested in winter and summer. In transitional seasons, they do not significantly affect, since during these periods the processes are unstable.

In winter, the Siberian maximum has a great influence on the climate of the East Siberian Sea. This determines the predominance of the southwestern and southern, the speed of which reaches 6 - 7 m / s. These winds move from the continent and therefore contribute to the spread of cold air. The average temperature in January is approximately - 28 - 30 ° С. In winter, the weather is mostly clear. Only sometimes cyclones disturb the well-established calm weather for several days. Atlantic cyclones, which prevail in the western part of the sea, increase the wind and increase. Pacific cyclones, which prevail in the southeastern part of the sea, bring strong winds and cloudy weather. On the coastlines with mountainous terrain, the Pacific cyclone contributes to the formation of strong winds - a hair dryer. As a result of this stormy wind, the temperature rises, while the air becomes less.

In summer, they form over the sea, and low over land. In this regard, the winds blow mainly north direction... At the beginning of the warm season, the winds are not yet gaining sufficient strength, but by the middle of summer their speed averages 6-7 m / s. By the end of summer, the western part of the sea turns into zones of strong storms. At this time, this section becomes the most dangerous along the entire route of the Northern Sea Route. Very often the wind speed reaches 10-15 m / s. In the southeastern part of the sea, such strong winds are not observed. The wind speed here can only increase in connection with the hair dryers. Constant winds from the north and north-east directions contribute to the preservation of low air temperatures. In the northern part of the sea, the average July temperature is about 0 - + 1 ° С, in the coastal areas the temperature is slightly higher than +2 - 3 ° С. The decrease in the temperature of the northern part of the sea is affected by the influence of ice. In the southern part of the sea, the proximity to the warm continent contributes to an increase in temperature. Cloudy is typical for the East Siberian Sea in summer. Very often it rains lightly, and occasionally even sleet.

East-Siberian Sea

In autumn, the influence of the Quiet and Atlantic oceans weakens, which affects the decline. Thus, the East Siberian Sea is characterized by a cold summer; unstable windy weather in the western and eastern regions of the sea in the summer-autumn period and calm in the central territories.

A small amount of river water flows into the East Siberian Sea. During the year, the volume is approximately 250 km 3. (the most big river flowing into this sea) brings about 132 km 3 per year. Another Indigirka gives 59 km 3. The rest of the rivers flowing into the East Siberian Sea are small, therefore they discharge small volumes of water. The largest amount of fresh water enters the southern part of the sea. The maximum flow occurs in the summer. Due to the small amount, fresh water does not flow far into the sea, but mainly spreads near river mouths. Due to the fact that the East Siberian Sea is large, the river runoff does not significantly affect it.

The waters of the East Siberian Sea are relatively clean. Only in the Pevek Bay there is a slight pollution of waters, but recently the ecological situation has been improving here. The waters of the Chaunskaya Bay are slightly polluted by hydrocarbons.