Give a description of the relief of Eastern Siberia. Geography of Eastern Siberia


The vast territory of Eastern Siberia, which occupies a quarter of the area of ​​Russia, stretches from the shores of the Arctic Ocean to the border with Mongolia, from the left bank of the Yenisei to the watershed ranges of the Far East.

The natural features of Eastern Siberia are determined by its size, location in middle and high latitudes, general inclination of the territory towards the low coast of the Arctic Ocean, and greater distance from the Atlantic Ocean. In addition, the barrier of mountain ranges nearly wipes out the influence of the Pacific Ocean.

In contrast to the West Siberian Plate, where flat landforms predominate, the Siberian Platform is dominated by uplands and plateaus. The Siberian platform belongs to the ancient platforms of the Precambrian age, which also distinguishes it from the young (from a geological point of view) West Siberian plate. The region under consideration occupies the central and northern part of eastern Siberia and is located between the Yenisei in the west and the Lena and Aldan in the east. In the west, this territory borders on the West Siberian plate, in the southwest and south it is surrounded by mountain structures of the Yenisei ridge - the Eastern Sayan system and the Baikal-Patom highlands, from the east - by the Verkhoyansk ridge. In the north, the platform is limited by the Taimyr-Severozemelskaya folded area.

Within Eastern Siberia, flat and mountainous territories are clearly distinguished. The most significant plain is the Central Siberian Plateau. Deep river valleys and small uplifts break the uniformity of the surface of this territory. Rivers are the transport system of the landscape. Large and small rivers of Eastern Siberia form a dense network. Despite the insignificant amount of precipitation, the rivers are full of water. This is explained by a short warm period during which a rapid flood occurs. All the rivers of this territory belong to the basin of the Arctic Ocean. The Yenisei flows along the western edge of the Central Siberian Plateau. Its most abundant right tributary is the Angara, flowing from Baikal, which regulates the flow of the river, making it uniform throughout the year. This favors the use of Angara's water energy.

10 km from Baikal, high in the mountains, the Lena River is born. Having received large tributaries, especially Aldan and Vilyui, it turns into a large flat river. When it flows into the sea, the Lena forms a huge delta, the largest in Russia, consisting of more than a thousand islands. Other large rivers, the Indigirka and the Kolyma, also flow into the seas of the Arctic Ocean. Lakes in this area are located unevenly. There are especially many of them in the northern and eastern parts.

Lake Baikal. Photo: Sergey Vladimirov

Lake Baikal has unique features. It has no equal in the world in terms of age, depth, reserves and properties of fresh water, diversity and endemism of organic life.

A characteristic feature of Eastern Siberia is permafrost. In most of Eastern Siberia, under the top layer of soil there is soil bound by cold, which never thaws. They call it permafrost. A new science emerged - permafrost science, or geocryology. Among all frozen and frosty rocks, the most difficult to study are dispersed rocks, that is, rocks consisting of many different small particles (clay, sand, etc.). Inside such rocks there are many small voids or pores. The water in these pores is in the form of ice, steam and liquid water. In frozen soils, there is indeed unfrozen water. Only there is very little of it and it is distributed over the particles of the soil with a thin film. So thin that it is not visible even with a magnifying glass. The water contained in the frozen rock can migrate, move in the ground, and freeze, forming layers of ice (schlieren) in the rock with a thickness of hundredths of a millimeter or more. Geological processes that occur during the freezing or thawing of rocks, as well as the freezing of groundwater, are called cryogenic. There are many types of perennial heaving mounds. One of them is injectable. It usually occurs in areas of small lakes. In winter, such a lake on permafrost freezes to the bottom. However, under it there are always rocks saturated with water. They also freeze. These rocks are, as it were, in a frozen bag: ice is on top of them, and permafrost is on the bottom. The volume of such a bag gradually decreases as it freezes, and the water of the rocks begins to put pressure on the walls and roof that hold them back. Finally, succumbing to this pressure, the frozen roof bends in the weakest place, forming a helmet-shaped heaving mound. The Yakuts call such hillocks "bulgunnyakhs". Their size can reach a height of 30-60 meters, and at the base of 100-200 meters. Bulgunnyakhs are most often found in Central Yakutia, in the Arctic coastal lowlands of northeastern Siberia.

A serious danger is the process of solifluction, characteristic of the permafrost zone, which develops on the slopes of hills, hills and ravines. Solifluction is the flow of loose, highly waterlogged soil masses along slopes. The usual ground flow rate is 2-10 cm per year. However, with heavy rains or intense melting, landslides occur. Phenomena such as icing are associated with water in the permafrost zone. Frosts are called ice influxes, formed as a result of freezing of river or lake waters poured onto the surface. When the upper part of the rocks freezes, an increasing hydrostatic pressure (water pressure) arises in them. This happens because water, turning into ice, increases in volume, squeezing unfrozen water, and at the same time blocking all exits to the surface. Meanwhile, water presses on the ice crust until it finally breaks through and splashes to the surface. But, once in the wild, the water quickly freezes and covers the hole it has just made with ice. And everything starts over. The thickness of the icing sometimes reaches 7-10 m, and the area is several tens of square kilometers. Only here is the trouble: on such ice, you can’t mark the places of the next exits of under-ice water, and water breaks free sometimes with a real explosion. And it's dangerous.

All these phenomena are widespread in Eastern and Northeastern Siberia.

The ice zone of Eastern Siberia is characterized by the exceptional severity of nature. On Severnaya Zemlya and the New Siberian Islands, large areas are occupied by glaciers. In the areas free from glaciers, in the Arctic desert, there is a "seasonal" snow cover almost all year round. In the summer, when it descends, the processes of frosty weathering proceed vigorously, and large-clastic deposits melt on the surface of the earth. Mosses, lichens, and some species of typically arctic flowering, mainly herbaceous, plants dominate in the sparse and poor vegetation cover of the Arctic desert. In the south of the zone there are squat shrubs - polar and arctic willows, etc. The arctic desert is inhabited by: arctic fox, polar bear, lemming, reindeer is rare. In the ice zone, fox, birds, marine animals, and wild reindeer are hunted. There is little population here, the fishing season is short, however, the number of many animals is declining and they need protection. In Russia, reserves have been organized to protect rare animals in the north of the Taimyr Peninsula and on Wrangel Island.

The North Siberian, Yano-Indigirskaya and Kolyma lowlands, the New Siberian Islands are tundras of flat plains. Rugged terrain, stony placers make the conditions for the existence of vegetation and wildlife, and hence the landscapes very diverse. Almost everywhere in the tundra zone, the ground is bound by ice. The first thing that catches your eye when you first see the tundra from the window of an airplane is the sparkling mirrors of many reservoirs. These are thermokarst lakes - they were formed as a result of thawing of permafrost and subsidence of the soil. The northern plains often resemble honeycombs. This is what polygonal tundras look like, which appear as a result of cracks in frozen ground. Life in the tundra adds its own patterns to those drawn by the permafrost, for example, lemming-hunting owls and skuas choose high ground to ambush and fertilize the soil with droppings. Tall grass grows here, and on a sunny summer day, a grid of bright green dots looks very picturesque from the air.

In the south, next to the forest, the tundra is similar to the northern taiga, only consisting of one undergrowth, without tall trees. The same green mosses, shrubs of lingonberries, blueberries, haddock, many dwarf birches, over which mushrooms sometimes rise - a kind of "birch trees". There are many mushrooms, they are clearly visible; thanks to the cool climate, they remain worm-free for a long time. For a mushroom picker, the tundra is a real paradise. The tundra is very beautiful twice a year. The first time is in August, when cloudberries ripen and the landscape changes color, first from green to red, and then to yellow. The second time - in September, when the leaves of dwarf birch and shrubs turn yellow and red. This is a golden autumn in miniature. For Eastern Siberia, the so-called tussock tundras are typical. Tussocks form sedges and cotton grass - a plant very characteristic of this zone. In English, cotton grass is called "cotton grass". Indeed, it is a herb with a fine white fiber tassel. Cotton grass also grows on the border of the tundra with the Arctic deserts. The peculiarity of the permafrost relief is also reflected in the pattern of the vegetation cover. So, for example, shrubs, mosses and sedges can grow along permafrost cracks, while the center of the "polygon" is covered only with algae or lichens, or completely bare. The tundra has a wide variety of insects. There are also ants here that build their dwellings from the hard leaves of shrubs or from the earth. Special mention must be made of mosquitoes and midges. In the tundra, the midge is able to turn life into a real hell. Reindeer climb the blown tops of the hills or descend to the coast: only there the wind saves them from blood-sucking insects. But there are very few of them in the tundra - these are amphibians and reptiles. The most primitive of reptiles, salamanders, are sometimes found in puddles, and representatives of only one species live in bushes - moored frogs. There are no snakes at all, the only reptile - a viviparous lizard - is found near the forest belt. And yet the tundra seems to be filled with life. This impression is created, first of all, by birds, of which there are a lot. And what kind of birds nest here! Large waterfowl - swans, geese, goose, ducks. They breed offspring in the tundra and then fly away in thousands of flocks to the south, to warm countries. The main animals of the tundra are the lemming, the arctic fox and the reindeer.

The forest zone occupies a vast territory of Central Siberia, up to about 60% of its entire area. The taiga of Central Siberia is characterized by a sharply continental climate and slight swampiness. The Central Siberian taiga is predominantly light coniferous taiga, consisting mainly of Naur larch and pine with a slight admixture of dark coniferous species - cedar, spruce and fir. The main reasons for the scarcity of the species composition of the eastern taiga are permafrost and a sharp continental climate. In connection with the elevated relief of the plateau, the flat taiga of Central Siberia merges in the south with the mountain taiga of the Sayan Mountains and the Baikal mountain country.

The Central Siberian taiga, when moving from north to south, is divided into three lanes. The northern strip of sparsely layered wetland forests goes south to the Arctic Circle. Larch swampy forests grow on gley-permafrost-taiga soils. The middle zone of the taiga occupies the basins of the Srednyaya and Nizhnyaya Tunguska and Vilyui rivers. In the basin of the Middle and Lower Tunguska, the taiga is more humid than in the Vilyui basin. The Central Siberian plateau is covered with spruce-cedar-larch taiga. The river valleys are dominated by spruce-cedar moss taiga with a slight admixture of larch. In the Vilyui basin, the Lena valley and the Lena-Aldan interfluve, taiga from Naur larch develops under conditions of insufficient moisture.

The southern strip of taiga occupies the basins of the Angara and the upper reaches of the Lena. In the western part, where the climate is somewhat warmer and wetter, the permafrost lies deep or is completely absent; here, on loamy and sandy soddy-podzolic soils, mainly pine grows. Larch dominates in the eastern part. In pine and deciduous forests, alder and Naur rhododendron grow in the undergrowth. The taiga of Central Siberia is a large raw material base for state procurements for the woodworking and wood-chemical industries. The main tree species are larch, pine, and cedar. Fur trade in the Central Siberian taiga occupies one of the first places among other regions.

The taiga has a more diverse and rich animal world than the tundra. Of the predators are common: brown bear, wolverine, fox, Siberian weasel, ermine, sable. Wolverine lives everywhere. Sable is rare and spread over stony placers in dense taiga. The lynx is the only animal from the cat family in the taiga. The habitat of the lynx is dense taiga forests. Of the artiodactyls in the taiga, elk and musk deer are common, and on the moss tundra of the Putorana Plateau there is a bighorn sheep. Maral and roe deer are common in the southern part of the Yenisei taiga. There is no continuous forest-steppe and steppe zone in Eastern Siberia. Only a few sections stand out.

The forest-steppe of Transbaikalia consists of steppe forb areas and pine forests or larch and birch copses with an undergrowth of Daurian rhododendron. The development of vegetation is significantly affected by cold and little snowy winters, dry and long springs, and short and rainy summers. Cold types of weather contribute to the development of pillow-shaped forms and curtains in plants. The vegetation of the steppes consists of feather grass, thin-legged, fescue and serpentine. The steppes and forest-steppes of Transbaikalia are the main agricultural regions. The steppes are used as pastures for livestock. Part of the territory is plowed under grain, garden and other crops.

In the mountains of North-Eastern Siberia, the altitudinal zonality of landscapes is clearly manifested. There are three high-altitude landscape zones on the Verkhoyansk Ridge. The first belt of north-taiga sparsely layered deciduous forests rises along the southern slopes up to 1200-1300 m, and up to 600-800 m along the northern slopes. Lichens predominate in the above ground cover; the shrub layer is formed by lingonberries, speedwells and wild rosemary. Along the river valleys, on sand and pebble deposits, gallery forests of fragrant poplar with an admixture of larch, birch, aspen and Siberian mountain ash stretch. Above the upper boundary of the larch forest, thickets of elfin cedar dominate with an admixture of shrubby alder with lichen-shrub cover.

The second belt is mountain-tundra. Its upper boundary should be drawn at the ends of the glaciers (1800-2100 m). This zone has harsh climatic conditions: in a long winter, low temperatures prevail, combined with strong winds and snowstorms. Climatic conditions contribute to the development of accumulative and wind-blown snowfields, avalanches, frost weathering, solifluction and icing (taryns). The icings are located below the ends of the glaciers at an altitude of 1100-1700 meters. The alpine type of relief prevails. The dominant type of tundra is lichen (cladonia and lecture), on gentle slopes - swampy tundra. The soils are mountain-tundra.

The third belt - perennial snows and glaciers; the snow limit lies at an altitude of 2250-2450 meters. Negative temperatures prevail all year round, but in winter frosts are much less than in neighboring valleys and plateaus. The average temperature of the warmest month at an altitude of 2800 meters is about +3? C. Strong winds prevail. The glaciers are surrounded by permafrost with very little seasonal thawing.

Approximately the same is observed in other mountains of North-Eastern Siberia: larch north-taiga rare-layer forests (on the flat bottoms of basins and valleys) and mountain larch forests (on the slopes of valleys and ridges) dominate in the lower altitudinal zone, higher - mountain tundra and bald mountains . In the south of the territory above larch trees thickets of dwarf pine and alder-cedar thickets are widespread.



General characteristics of North-Eastern Siberia

To the east of the lower reaches of the Lena lies a vast territory, bounded in the east by the mountain ranges of the Pacific watershed. This physical and geographical country was named North-Eastern Siberia. Including the islands of the Arctic Ocean, North-Eastern Siberia covers an area of ​​more than $1.5 million sq. km. Within its borders is the eastern part of Yakutia and the western part of the Magadan region. North-Eastern Siberia is located in high latitudes and is washed by the waters of the Arctic Ocean and its seas.

Cape Svyatoi Nos is the northernmost point. The southern regions are in the Mai River basin. Almost half of the country's territory is located north of the Arctic Circle, which is characterized by a diverse and contrasting relief. There are mountain ranges, plateaus, flat lowlands along the valleys of large rivers. Northeastern Siberia belongs to the Verkhoyansk-Chukotka Mesozoic folding, when the main folding processes took place. The modern relief was formed as a result of the latest tectonic movements.

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The climatic conditions of North-Eastern Siberia are severe, January frosts reach -$60$, -$68$ degrees. Summer temperature +$30$, +$36$ degrees. The temperature amplitude in some places is $100$-$105$ degrees, there is little precipitation, about $100$-$150$ mm. Permafrost fetters the soil to a depth of several hundred meters. On the flat territories, the distribution of soils and vegetation cover is well expressed in zonality - on the islands, the zone of arctic deserts, continental tundra and monotonous swampy larch woodlands. Altitudinal zonality is characteristic of mountainous regions.

Remark 1

Explorers I. Rebrov, I. Erastov, M. Stadukhin delivered the first information about the nature of North-Eastern Siberia. It was the middle of the $XVII$ century. The northern islands were studied by A.A. Bunge and E.V. Toll, but the information was far from complete. Only in the $30$ years of the expedition of S.V. Obruchev changed the ideas about the features of this physical and geographical country.

Despite the diversity of the relief, North-Eastern Siberia is mainly a mountainous country, lowlands occupy $20% of the area. The mountain systems of the outlying ranges of the Verkhoyansk, Chersky, Kolyma Uplands are located here. In the south of North-Eastern Siberia there are the highest mountains, the average height of which reaches $1500$-$2000$ m. whose height is $3147$ m.

Geological structure of the North-East of Siberia

In the Paleozoic era and at the beginning of the Mesozoic era, the territory of North-Eastern Siberia belonged to the Verkhoyansk-Chukotka geosynclinal marine basin. The main evidence of this is the thick Paleozoic-Mesozoic deposits, reaching $20$-$22 thousand meters in places, and strong tectonic movements, which created folded structures in the second half of the Mesozoic. The most ancient structural elements include the median massifs Kolyma and Omolon. A younger age - Upper Jurassic in the west, and Cretaceous in the east - have other tectonic elements.

These elements include:

  1. Verkhoyansk folded zone and Sette - Dabansky atiklinorium;
  2. Yanskaya and Indigirsko-Kolyma synclinal zones;
  3. Tas-Khayakhtakhsky and Momsky anticlinoria.

By the end of the Cretaceous, northeastern Siberia was a territory elevated above neighboring regions. The warm climate of that time, and the denudation processes of mountain ranges leveled the relief and formed flat surfaces of leveling. The modern mountain relief was formed under the influence of tectonic uplifts in the Neogene and Quaternary period. The amplitude of these uplifts reached $1000$-$2000m. Cenozoic subsidences are occupied by lowlands and intermountain basins with strata of loose deposits.

Approximately from the middle of the Quaternary period, glaciation began, on mountain ranges that continued to rise, large valley glaciers appeared. The glaciation had an embryonic character, according to D.M. Kolosov, on the plains, firn fields formed here. The formation of permafrost begins in the second half of the Quaternary in the archipelago of the New Siberian Islands and in the coastal lowlands. The thickness of permafrost and ground ice reaches $50$-$60$ m in the cliffs of the Arctic Ocean.

Remark 2

The glaciation of the plains of northeastern Siberia was thus passive. A significant part of the glaciers were slow-moving formations that carried little loose material. The exaration impact of these glaciers had little effect on the relief.

Mountain-valley glaciation is better expressed, on the outskirts of mountain ranges there are well-preserved forms of glacial exaration - cirques, trough valleys. Valley Middle Quaternary glaciers reached a length of $200$-$300$ km. The mountains of North-Eastern Siberia, according to most experts, experienced three independent glaciations in the Middle Quaternary and Upper Quaternary.

These include:

  1. Tobychanskoe glaciation;
  2. Elga glaciation;
  3. Bokhapcha glaciation.

The first glaciation led to the appearance of Siberian conifers, including Dahurian larch. During the second interglacial epoch, mountain taiga prevailed. It is typical for the southern regions of Yakutia at the present time. The last glaciation had almost no effect on the species composition of modern vegetation. The northern limit of the forest at that time, according to A.P. Vaskovsky, was noticeably shifted to the south.

The relief of the North-East of Siberia

The relief of North-Eastern Siberia forms several well-defined geomorphological tiers. Each stage is associated with a hypsometric position, which was determined by the nature and intensity of the latest tectonic movements. The position in high latitudes and the sharp continentality of the climate cause different altitudinal limits of the distribution of the corresponding types of mountainous relief. In its formation, the processes of nivation, solifluction, and frost weathering are of greater importance.

Within North-Eastern Siberia, in accordance with morphogenetic features, the following are distinguished:

  1. Accumulative plains;
  2. Erosion-denudation plains;
  3. Plateau;
  4. low mountains;
  5. Mid-mountain and low-mountain alpine relief.

Separate areas of tectonic subsidence occupy accumulative plains, characterized by a slightly rugged relief and small fluctuations in relative height. Such forms are spreading, which owe their formation to permafrost processes, large ice content of loose deposits and thick underground ice.

Among them are:

  1. Thermokarst basins;
  2. Permafrost heaving mounds;
  3. Frost cracks and polygons;
  4. High ice cliffs on the sea coasts.

The accumulative plains include the Yano-Indigirskaya, Sredne-Indigirskaya, and Kolyma lowlands.

At the foot of a number of ridges - Anyuisky, Momsky, Kharaulakhsky, Kulara - formed erosion-denudation plains. The surface of the plains has a height of no more than $200$ m, but can reach $400$-$500$ m near the slopes of a number of ridges. Loose deposits here are thin and they are composed mainly of bedrock of different ages. As a result, gravel placers, narrow valleys with rocky slopes, low hills, spots-medallions, and solifluction terraces can be found here.

Between the Verkhoyansky ridge and the Chersky ridge there is a pronounced plateau terrain- Yanskoye, Elginskoye, Oymyakonskoye, Nerskoye plateaus. Most of the plateaus are composed of Mesozoic deposits. Their modern height is from $400$ to $1300$ m.

Those areas that were subjected to uplifts of moderate amplitude in the Quaternary are occupied low mountains, with a height of $300$-$500$ m. They occupy a marginal position and are dissected by a dense network of deep river valleys. Typical landforms for them are an abundance of stony placers and rocky peaks.

Middle mountain relief is mainly characteristic of most of the massifs of the Verkhoyansk Range system. Yudomo-May Highland, Chersky Ridge, Tas-Khayakhtakh, Momsky. In the Kolyma Highlands and the Anyui Range, there are also mid-mountain massifs. Their height is from $800$-$2200$ m. The mid-mountain massifs of North-Eastern Siberia are located in the mountain tundra, above the upper limit of woody vegetation.

High Alpine relief. These are the ridges of the highest mountain ranges - Suntar-Khayata, Ulakhan-Chistai, Tas-Khayakhtakh, etc. They are associated with the areas of the most intense uplifts of the Quaternary period. The height is more than $2000$-$2200$ m. The activity of Quaternary and modern glaciers plays a significant role in the formation of the Alpine relief, therefore, large amplitudes of heights, deep dissection, narrow rocky ridges, cirques, cirques and other glacial landforms will be characteristic.

The hydrographic network of Eastern Siberia belongs to the basin of the Arctic Ocean and is distributed over the private basins of the Kara, Laptev, East Siberian and Chukchi Seas. By the nature of the relief, Eastern Siberia belongs to mountainous regions, and here mountains of medium height and vast plateaus predominate, while lowlands occupy only small spaces.

Between the Yenisei and Lena is the Siberian Plateau, dissected by erosion. Its height is on average 300-500 m above sea level; only in places among the plateau stand out higher elevations - the Putorana ridge (1500 m), the Vilyui mountains (1074 m) and the Yenisei ridge (1122 m). In the upper part of the Yenisei basin is the Sayano-Baikal fold country. This is the highest mountain region of the region, with heights up to 3480 m (the peak of Munku-Sardyk).

To the east of the lower reaches of the Lena stretches the Verkhoyansk-Kolyma mountainous country, characterized by sharp contrasts of lowland and mountain landscapes. Along the right bank of the Lena stretches a powerful arc of the Verkhoyansk ridge with heights up to 2000 m, further to the east rises the Chersky ridge - a mountain knot with a height of 2000-3000 m, the Tas-Khayakhtakh ridge, etc. Along with the mountain ranges, the Verkhoyansk-Kolyma mountain region includes Oymyakonskoe, Nerskoe and Yukagir plateaus. In the south, the border of the region is made up of the Yablonovy, Stanovoy and Duzhgdzhur ridges, whose heights reach 2500-3000 m. In the east, the Kolyma Range, or Gydan, stretches along the coast of the Sea of ​​Okhotsk.

On the territory of Eastern Siberia, there are also low-lying plains, among which the Lena-Vilyui lowland stands out for its size, which is a grandiose synclinal trough. The extreme north of the region, along the coast of the marginal seas, is occupied by the Subpolar Lowland, the height of which does not exceed 100 m above sea level; lowlands are also located in the lower reaches of the Alazeya, Kolyma and Indigirka.

The subpolar lowland is occupied by tundra and forest tundra. Most of the territory of Eastern Siberia belongs to the taiga zone. The forest landscape is dominated by Daurian larch, which is most adapted to the harsh climate and the presence of permafrost; much less pine here. The forests of Eastern Siberia are slightly swamped.

The taiga zone on the territory of Eastern Siberia is dominant and extends far to the south; sections of the steppe and forest-steppe are interspersed in it in the form of spots (the Minusinsk depression, which has a steppe character, the steppes of Transbaikalia).

Geologically, the area is characterized by a shallow occurrence of bedrock crystalline rocks, which often come to the surface here. Ancient igneous rocks - traps, which form characteristic vertical outcrops in the form of columnar units (locally - pillars) are widely distributed, especially within the Central Siberian Plateau.

The rivers of Eastern Siberia are predominantly in the form of mountain streams; flowing through the lowlands, they acquire a flat character.

Eastern Siberia is part of the Asian territory of the Russian Federation. It is located from the borders of the Pacific Ocean to the Yenisei River. This zone is characterized by an extremely harsh climate and limited fauna and flora.

Geographic Description

Eastern and occupy almost two-thirds of the territory of Russia. They are located on the plateau. The eastern zone covers an area of ​​about 7.2 million square meters. km. Its possessions extend up to the Sayan mountain ranges. Most of the territory is represented by the tundra lowland. The mountains of Transbaikalia play a significant role in the formation of the relief.

Despite the harsh climatic conditions, there are quite a lot of large cities in Eastern Siberia. The most attractive from an economic point of view are Norilsk, Irkutsk, Chita, Achinsk, Yakutsk, Ulan-Ude, and others. Within the zone are the Zabaikalsky and Krasnoyarsk Territories, the republics of Yakutia, Buryatia, Tuva and other administrative regions.

The main type of vegetation is the taiga. It will be washed from Mongolia to the borders of the forest-tundra. Occupies over 5 million sq. km. Most of the taiga is represented by coniferous forests, which make up 70% of the local vegetation. Soils develop unevenly relative to natural zones. In the taiga zone, the soil is favorable, stable, in the tundra - rocky, frozen.

Within the interfluve and lowlands, insignificant swamps are observed. However, they are much less than in the same Western Siberia. But in the eastern region, arctic deserts and deciduous plantations are often found.

Terrain characteristics

Eastern Siberia of Russia is located at a high level above the sea. All the fault of the plateau, which is located in the middle part of the zone. Here the height of the platform varies from 500 to 700 meters above sea level. The relative averageness of the region is noted. The highest points are the interfluve of the Lena and the Vilyui plateau - up to 1700 meters.

The base of the Siberian platform is represented by a crystalline folded basement, on which there are huge sedimentary layers up to 12 kilometers thick. The north of the zone is determined by the Aldan shield and the Anabar massif. The average thickness of the soil is about 30 kilometers.

To date, the Siberian platform contains several main types of rocks. These are marble, and schist, and charnockite, etc. The oldest deposits date back to 4 billion years. Igneous rocks were formed as a result of eruptions. Most of these deposits are located in and also in the Tunguska depression.

The modern relief is a combination of lowlands and uplands. Rivers flow in the valleys, swamps form, coniferous trees grow better on the hills.

Features of the water area

It is generally accepted that the Far East faces the Arctic Ocean with its "facade". The eastern region borders on such seas as the Kara, Siberian and Laptev. Of the largest lakes, it is worth highlighting Baikal, Lama, Taimyr, Pyasino and Khantayskoye.

Rivers flow in deep valleys. The most significant of them are the Yenisei, Vilyui, Lena, Angara, Selenga, Kolyma, Olekma, Indigirka, Aldan, Lower Tunguska, Vitim, Yana and Khatanga. The total length of the rivers is about 1 million km. Most of the inland basin of the region belongs to the Arctic Ocean. Other external water areas include such rivers as Ingoda, Argun, Shilka and Onon.

The main source of food for the inner basin of Eastern Siberia is the snow cover, which melts in large volumes under the influence of sunlight from the beginning of summer. The next most important role in the formation of the continental water area is played by rains and groundwater. The highest level of the basin's runoff is observed in the summer.

The largest and most important river in the region is the Kolyma. Its water area occupies more than 640 thousand square meters. km. The length is about 2.1 thousand km. The river originates in the Upper Kolyma Highlands. Water consumption exceeds 120 cubic meters per year. km.

Eastern Siberia: climate

The formation of meteorological features of the region is determined by its territorial location. The climate of Eastern Siberia can be briefly described as continental, consistently severe. There are significant seasonal fluctuations in cloudiness, temperature, and precipitation levels. The Asian anticyclone forms vast areas of high pressure in the region, especially this phenomenon occurs in winter. On the other hand, severe frost makes air circulation changeable. Because of this, temperature fluctuations at different times of the day are more significant than in the west.

The climate of North-Eastern Siberia is represented by changeable air masses. It is characterized by increased precipitation and dense snow cover. This area is dominated by continental flows, which are rapidly cooling in the ground layer. That is why in January the temperature drops to a minimum. Arctic winds prevail at this time of the year. Often in winter, you can observe air temperatures down to -60 degrees. Basically, such minima are inherent in depressions and valleys. On the plateau, the indicators do not drop below -38 degrees.

Warming is observed with the arrival of air flows from China and Central Asia to the region.

winter time

No wonder it is believed that Eastern Siberia has the heaviest and most severe. The table of temperature indicators in winter is proof of this (see below). These indicators are presented as average values ​​for the last 5 years.

Due to the increased dryness of the air, the constancy of the weather and the abundance of sunny days, such low rates are easier to tolerate than in a humid climate. One of the defining meteorological characteristics of winter in Eastern Siberia is the absence of wind. Most of the season there is a moderate calm, so there are practically no blizzards and snowstorms here.

Interestingly, in the middle part of Russia, a frost of -15 degrees is felt much stronger than in Siberia -35 C. Nevertheless, such low temperatures significantly worsen the living conditions and activities of local residents. All living quarters have thickened walls. Expensive fuel boilers are used to heat buildings. The weather begins to improve only with the onset of March.

warm seasons

In fact, spring in this region is short, as it comes late. The eastern one, which changes only with the arrival of warm Asian air currents, begins to wake up only by mid-April. It is then that the stability of positive temperatures during the daytime is noted. Warming comes in March, but it is insignificant. By the end of April, the weather begins to change for the better. In May, the snow cover completely melts, the vegetation blooms.

In summer, the weather becomes relatively hot in the south of the region. This is especially true for the steppe zone of Tuva, Khakassia and Transbaikalia. In July, the temperature here rises to +25 degrees. The highest rates are observed on flat terrain. It is still cool in the valleys and highlands. If we take the whole of Eastern Siberia, then the average summer temperature here is from +12 to +18 degrees.

Climate features in autumn

Already at the end of August, the first frosts begin to envelop the Far East. They are observed mainly in the northern part of the region at night. During the day the bright sun shines, it rains with sleet, sometimes the wind intensifies. It is worth noting that the transition to winter is much faster than from spring to summer. In the taiga, this period takes about 50 days, and in the steppe area - up to 2.5 months. All these are characteristic features that distinguish Eastern Siberia from other northern zones.

The climate in autumn is also represented by an abundance of rains coming from the west. Moist Pacific winds blow most often from the east.

Precipitation level

Relief is responsible for atmospheric circulation in Eastern Siberia. Both the pressure and the speed of air mass flows depend on it. About 700 mm of precipitation falls annually in the region. The maximum indicator for the reporting period is 1000 mm, the minimum is 130 mm. The level of precipitation is not clearly defined.

On the plateau in the middle lane, it rains more often. Due to this, the amount of precipitation sometimes exceeds the mark of 1000 mm. The most arid region is Yakutsk. Here the amount of precipitation varies within 200 mm. The least rain falls between February and March - up to 20 mm. The western regions of Transbaikalia are considered the optimal zones for vegetation with respect to precipitation.

Eternal Frost

Today there is no place in the world that could compete in terms of continentality and meteorological anomalies with a region called Eastern Siberia. The climate in some areas is striking in its severity. In the immediate vicinity of the Arctic Circle lies the permafrost zone.

This area is characterized by low snow cover and low temperatures throughout the year. Because of this, mountain weather and the ground lose a huge amount of heat, freezing to whole meters in depth. The soils here are mostly stony. Groundwater is underdeveloped and often freezes for decades.

Vegetation of the region

The nature of Eastern Siberia is mostly represented by taiga. Such vegetation extends for hundreds of kilometers from the Lena River to the Kolyma. In the south, the taiga borders on the local possessions are untouched by man. However, due to the arid climate, the threat of large-scale fires always hangs over them. In winter, the temperature in the taiga drops to -40 degrees, but in summer the figures often rise to +20. Rainfall is moderate.

Also, the nature of Eastern Siberia is represented by the tundra zone. This zone is adjacent to the Arctic Ocean. The soils here are bare, the temperature is low, and the humidity is excessive. Flowers such as cotton grass, gravel, poppy, saxifrage grow in mountainous areas. From the trees of the region, one can distinguish spruces, willows, poplars, birches, pines.

Animal world

Almost all regions of Eastern Siberia are not rich in fauna. The reasons for this are permafrost, lack of food and underdevelopment of deciduous flora.

The largest animals are the brown bear, lynx, elk and wolverine. Sometimes you can meet foxes, ferrets, stoats, badgers and weasels. Musk deer, sable, deer and bighorn sheep live in the central strip.

Due to the eternally frozen soil, only a few species of rodents are found here: squirrels, chipmunks, flying squirrels, beavers, marmots, etc. But the feathered world is extremely diverse: capercaillie, crossbill, hazel grouse, goose, crow, woodpecker, duck, nutcracker, sandpiper, etc. .

General characteristics of North-Eastern Siberia

To the east of the lower reaches of the Lena lies a vast territory, bounded in the east by the mountain ranges of the Pacific watershed. This physical and geographical country was named North-Eastern Siberia. Including the islands of the Arctic Ocean, North-Eastern Siberia covers an area of ​​more than $1.5 million sq. km. Within its borders is the eastern part of Yakutia and the western part of the Magadan region. North-Eastern Siberia is located in high latitudes and is washed by the waters of the Arctic Ocean and its seas.

Cape Svyatoi Nos is the northernmost point. The southern regions are in the Mai River basin. Almost half of the country's territory is located north of the Arctic Circle, which is characterized by a diverse and contrasting relief. There are mountain ranges, plateaus, flat lowlands along the valleys of large rivers. Northeastern Siberia belongs to the Verkhoyansk-Chukotka Mesozoic folding, when the main folding processes took place. The modern relief was formed as a result of the latest tectonic movements.

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The climatic conditions of North-Eastern Siberia are severe, January frosts reach -$60$, -$68$ degrees. Summer temperature +$30$, +$36$ degrees. The temperature amplitude in some places is $100$-$105$ degrees, there is little precipitation, about $100$-$150$ mm. Permafrost fetters the soil to a depth of several hundred meters. On the flat territories, the distribution of soils and vegetation cover is well expressed in zonality - on the islands, the zone of arctic deserts, continental tundra and monotonous swampy larch woodlands. Altitudinal zonality is characteristic of mountainous regions.

Remark 1

Explorers I. Rebrov, I. Erastov, M. Stadukhin delivered the first information about the nature of North-Eastern Siberia. It was the middle of the $XVII$ century. The northern islands were studied by A.A. Bunge and E.V. Toll, but the information was far from complete. Only in the $30$ years of the expedition of S.V. Obruchev changed the ideas about the features of this physical and geographical country.

Despite the diversity of the relief, North-Eastern Siberia is mainly a mountainous country, lowlands occupy $20% of the area. The mountain systems of the outlying ranges of the Verkhoyansk, Chersky, Kolyma Uplands are located here. In the south of North-Eastern Siberia there are the highest mountains, the average height of which reaches $1500$-$2000$ m. whose height is $3147$ m.

Geological structure of the North-East of Siberia

In the Paleozoic era and at the beginning of the Mesozoic era, the territory of North-Eastern Siberia belonged to the Verkhoyansk-Chukotka geosynclinal marine basin. The main evidence of this is the thick Paleozoic-Mesozoic deposits, reaching $20$-$22 thousand meters in places, and strong tectonic movements, which created folded structures in the second half of the Mesozoic. The most ancient structural elements include the median massifs Kolyma and Omolon. A younger age - Upper Jurassic in the west, and Cretaceous in the east - have other tectonic elements.

These elements include:

  1. Verkhoyansk folded zone and Sette - Dabansky atiklinorium;
  2. Yanskaya and Indigirsko-Kolyma synclinal zones;
  3. Tas-Khayakhtakhsky and Momsky anticlinoria.

By the end of the Cretaceous, northeastern Siberia was a territory elevated above neighboring regions. The warm climate of that time, and the denudation processes of mountain ranges leveled the relief and formed flat surfaces of leveling. The modern mountain relief was formed under the influence of tectonic uplifts in the Neogene and Quaternary period. The amplitude of these uplifts reached $1000$-$2000m. Cenozoic subsidences are occupied by lowlands and intermountain basins with strata of loose deposits.

Approximately from the middle of the Quaternary period, glaciation began, on mountain ranges that continued to rise, large valley glaciers appeared. The glaciation had an embryonic character, according to D.M. Kolosov, on the plains, firn fields formed here. The formation of permafrost begins in the second half of the Quaternary in the archipelago of the New Siberian Islands and in the coastal lowlands. The thickness of permafrost and ground ice reaches $50$-$60$ m in the cliffs of the Arctic Ocean.

Remark 2

The glaciation of the plains of northeastern Siberia was thus passive. A significant part of the glaciers were slow-moving formations that carried little loose material. The exaration impact of these glaciers had little effect on the relief.

Mountain-valley glaciation is better expressed, on the outskirts of mountain ranges there are well-preserved forms of glacial exaration - cirques, trough valleys. Valley Middle Quaternary glaciers reached a length of $200$-$300$ km. The mountains of North-Eastern Siberia, according to most experts, experienced three independent glaciations in the Middle Quaternary and Upper Quaternary.

These include:

  1. Tobychanskoe glaciation;
  2. Elga glaciation;
  3. Bokhapcha glaciation.

The first glaciation led to the appearance of Siberian conifers, including Dahurian larch. During the second interglacial epoch, mountain taiga prevailed. It is typical for the southern regions of Yakutia at the present time. The last glaciation had almost no effect on the species composition of modern vegetation. The northern limit of the forest at that time, according to A.P. Vaskovsky, was noticeably shifted to the south.

The relief of the North-East of Siberia

The relief of North-Eastern Siberia forms several well-defined geomorphological tiers. Each stage is associated with a hypsometric position, which was determined by the nature and intensity of the latest tectonic movements. The position in high latitudes and the sharp continentality of the climate cause different altitudinal limits of the distribution of the corresponding types of mountainous relief. In its formation, the processes of nivation, solifluction, and frost weathering are of greater importance.

Within North-Eastern Siberia, in accordance with morphogenetic features, the following are distinguished:

  1. Accumulative plains;
  2. Erosion-denudation plains;
  3. Plateau;
  4. low mountains;
  5. Mid-mountain and low-mountain alpine relief.

Separate areas of tectonic subsidence occupy accumulative plains, characterized by a slightly rugged relief and small fluctuations in relative height. Such forms are spreading, which owe their formation to permafrost processes, large ice content of loose deposits and thick underground ice.

Among them are:

  1. Thermokarst basins;
  2. Permafrost heaving mounds;
  3. Frost cracks and polygons;
  4. High ice cliffs on the sea coasts.

The accumulative plains include the Yano-Indigirskaya, Sredne-Indigirskaya, and Kolyma lowlands.

At the foot of a number of ridges - Anyuisky, Momsky, Kharaulakhsky, Kulara - formed erosion-denudation plains. The surface of the plains has a height of no more than $200$ m, but can reach $400$-$500$ m near the slopes of a number of ridges. Loose deposits here are thin and they are composed mainly of bedrock of different ages. As a result, gravel placers, narrow valleys with rocky slopes, low hills, spots-medallions, and solifluction terraces can be found here.

Between the Verkhoyansky ridge and the Chersky ridge there is a pronounced plateau terrain- Yanskoye, Elginskoye, Oymyakonskoye, Nerskoye plateaus. Most of the plateaus are composed of Mesozoic deposits. Their modern height is from $400$ to $1300$ m.

Those areas that were subjected to uplifts of moderate amplitude in the Quaternary are occupied low mountains, with a height of $300$-$500$ m. They occupy a marginal position and are dissected by a dense network of deep river valleys. Typical landforms for them are an abundance of stony placers and rocky peaks.

Middle mountain relief is mainly characteristic of most of the massifs of the Verkhoyansk Range system. Yudomo-May Highland, Chersky Ridge, Tas-Khayakhtakh, Momsky. In the Kolyma Highlands and the Anyui Range, there are also mid-mountain massifs. Their height is from $800$-$2200$ m. The mid-mountain massifs of North-Eastern Siberia are located in the mountain tundra, above the upper limit of woody vegetation.

High Alpine relief. These are the ridges of the highest mountain ranges - Suntar-Khayata, Ulakhan-Chistai, Tas-Khayakhtakh, etc. They are associated with the areas of the most intense uplifts of the Quaternary period. The height is more than $2000$-$2200$ m. The activity of Quaternary and modern glaciers plays a significant role in the formation of the Alpine relief, therefore, large amplitudes of heights, deep dissection, narrow rocky ridges, cirques, cirques and other glacial landforms will be characteristic.

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