And at the tops are located. It dominates here, and sometimes drops to -70 ° С.

In the mountains of North-Eastern Siberia, it is clearly manifested (and the vegetation depends on the height above sea level). So, for example, three high-altitude landscape zones are distinguished.

The third is the belt of perennial snows and glaciers. The snow border is located at an altitude of 2250-2450 meters. The temperature in this zone practically throughout the year does not rise above zero. However, winters are milder than in neighboring valleys and plateaus. The average temperature of the warmest month at an altitude of 2800 meters is about +3°C. In addition, quite strong and cold winds blow at such a high altitude. Around the glaciers are permafrost with a small layer of seasonal thawing.

Approximately the same zonality is observed in other mountains of northeastern Siberia. In the lower altitudinal zone, larch sparsely layered north-taiga forests (in basins and valleys) and mountain larch sparse forests (on the slopes of valleys and ridges) predominate, and in the upper zone - mountain tundra and bald mountains. Thickets of dwarf pine and alder-cedar thickets are widespread in the south.

Chersky Ridge- one of the largest mountain systems of North-Eastern Siberia on the territory of the Republic of Sakha (Yakutia) and the Magadan region. It stretched from the lower reaches of the Yana to the upper reaches of the Kolyma for a distance of about 1500 km. The width of the ridge reaches 400 km. The Charsky Ridge consists of two independent chains (Bilibina and Obruchev), which are separated by the Momo-Selennyakhskaya and the Indigirka valley.

The Bilibin chain includes the Selennyakhsky Range (length about 240 km, height up to 1460 m), the continuation of which on the right bank of the Indigirka is (length about 470 km, height up to 2530 m). The Obruchev chain is part of a mountain system that is complex in its relief; inside, two mountainous regions can be distinguished: northwestern and southeastern.

The chain of ridges of the northwestern region begins with the Burkat ridge (altitude up to 1150 m). Its continuation is the Hadaranya ridges (altitude 2185 m) and the Tas-Khayakhtakh ridge (altitude 2355 m). The chain is completed by the Chemalginsky Range (height 2550 m), which separates the Momo-Selennyakh depression from the Chibagalakh river valley. Other mountain ranges of the Obruchev chain are located along the left bank of the Indigirka River (Porozhny, Inyalinsky, Silyapsky, Volchansky). They are located parallel to the high-mountainous Chibagapakh Range (length 250 km, height 2450 m), which acts as a watershed for the Chibagalakh and Adycha rivers. Between the basins of the Yana and the Indigirka are the Elga plateau (up to 1590 m high) and (up to 1400 m high).

In the southeastern part of the chain, the Ulakhan-Chistai ridge (length 250 km) stands out, the top of which Mount Pobeda (3147 m) is the highest point of the entire mountain system. It is located in the Buordah high mountain range, separated from the ridge by a through gorge of the Tirekhtyakh River. The Ulakhan-Chistai Ridge is divided into separate massifs and serves as the watershed of Moma and Mera, Indigirka and Kolyma. It continues with a chain of short mid-mountain ranges. The valley of the river Erikit separates the Ulakhan-Chistai range from two short typical mid-mountain ranges - Khayargastakh (height up to 2193 m) and Erikitsky (height up to 2341 m), which form the northeastern and eastern borders of the entire mountain system. Its western border is the Tas-Kystabyt ridge (altitude up to 2341 m).

There are about 100 glaciers on the Ulakhan-Chistai ridge, the total area of ​​which is 85 km2 (90% is concentrated in the Buordah massif). In general, over 350 glaciers with a total area of ​​about 157 km2 are located on the territory of the Chersky Ridge. There are 69 passes and 4 peaks in the system of the Chersky ridge.

Verkhoyansk Range formed by a large number of individual mountain ranges, massifs and depressions separating them. The Verkhoyansk Range forms a watershed with Yana and Omoloy. It stretches for 1200 km from the Lena delta to the Tompo River (the right tributary of the Aldan), while forming an arc bulging to the southeast. The width of the Verkhoyansk Range ranges from 100 to 250 km. The southeastern continuation of the ridge is called the Sette-Daban ridge, which is distinguished by a different relief and. The northern end is formed by the Tuora-Sis and Kharaulakhsky ranges (height 1000-1250 m).

The highest points are located within the Orulgan ridge 2100-2300 m (highest point 2389 m). A narrow and long Kular ridge branches off to the east from the Orulgan ridge, the height of which reaches 1300 m. In the latitudinal section of the Verkhoyansk ridge, the heights exceed 2000 m. The passes lie at altitudes of 1300-1500 m. The river valleys of the western and southern slopes are deep. On the tops of the ridges and massifs, there are sections of an ancient leveled relief, better preserved in the Yana basin. The Verkhoyansk Ridge is composed of siltstones, sandstones, shales, and, more rarely, limestones.

On the tops of the highest ridges, cold prevails. Lower down the slopes, small amounts of mountain-tundra vegetation appear on gravelly and loamy soils. In the south, the lower parts of the slopes of the mountains up to a height of 800-1200 m are covered with larch forests. Sometimes there are steppe areas and forests formed by pine and birch, occasionally spruce, poplar, as well as thickets of shrubs.

The nature of Eastern Siberia is very vulnerable, in this region everything is interconnected. The resources of Eastern Siberia are inexhaustible. Picturesque mountain ranges with rocky peaks. There are impassable terrain here: forests and swamps; very vast steppes. In winter, there are big frosts, and in summer, hot days are like in the desert.

Flora and fauna of Eastern Siberia

The trees in Eastern Siberia are very different: pine, cedar, spruce, fir, but the most common tree here is larch (in Eastern Siberia there are two types of it - Daurian and Siberian larch). A person who rarely visits the taiga is unlikely to distinguish these two species from each other.

The squirrel is the most important fur species in the animal world of Eastern Siberia. A resident of the mountains of this area is the black-capped or Kamchatka marmot. In the forests of Eastern Siberia, the Asiatic wood mouse, Siberian red and red-gray voles are common. The Tuvan beaver needs protection and is listed in the Red Book of Russia.

In Altai and Yenisei in the regions of South-Eastern Siberia, such a species as the Asian long-tailed ground squirrel is common. The American ground squirrel lives in the Northeast. In the taiga part, the forest lemming, the highland Siberian vole and several other species are considered very rare animals. Of the bats, there are few water bats and northern leather bats.

There are 10 species of insects in eastern Siberia. Such as the Siberian cat, Dahurian hedgehog. Several species of shrews, one of them is a tiny and flat-headed shrew.

Of the large animals of the East Siberian taiga, the most common are the brown bear, lynx, and elk. There are foxes - red or gray foxes. Small predators - columns, forest ferret; badger, ermine, weasel (in the south). Sable and reindeer are considered numerous. Many different rodents - squirrel (the main object of hunting), hare, flying squirrel, mouse-like rodents. Roe deer and beaver have survived in some places.

Northeast Siberia

Harsh climate and permafrost. The temperature in winter reaches -60...-68 degrees, and in summer the heat reaches 30-36. The far north is dominated by arctic deserts with poor vegetation. To the south is the tundra zone. Deciduous forests occupy the lower parts of the mountain slopes.

The fauna of North-Eastern Siberia differs from the fauna of other regions of Siberia. In the mountains and on the plains, mammals and birds appear that are close to common animals in North America. This is explained by the fact that earlier there was land on the site of the Bering Strait.

The fauna is rich in steppe animals, which are not found anywhere in the north. In the high-mountainous rocky tundra, one can meet the Verkhoyansk black-capped marmot, and in the glades of the mountain-taiga zone, the long-tailed Kolyma ground squirrel. Among mammals, various rodents and shrews (more than 20 species) live in the mountains.

Of the predators - the Bering bear, East Siberian lynx, arctic fox, sable, ermine. Among birds, stone grouse, nutcracker, hazel grouse are common. In summer, scoter, bean goose and others (waterfowl) are found on the lakes.

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 nutrition 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. .

Physical geography of Russia and the USSR
Asian part: Central Asia and Kazakhstan, Siberia, Far East

Northeast Siberia

general characteristics

A vast territory lying to the east of the lower reaches of the Lena, north of the lower reaches of the Aldan and bounded in the east by the mountain ranges of the Pacific watershed, forms the country of North-Eastern Siberia. Its area (together with the islands of the Arctic Ocean that make up the country) exceeds 1.5 million square kilometers. km 2. The eastern part of the Yakut Autonomous Soviet Socialist Republic and the western regions of the Magadan Region are located within North-Eastern Siberia.

Northeastern Siberia is located in high latitudes and is washed by the seas of the Arctic Ocean in the north. The extreme northern point of the mainland - Cape Svyatoy Nos - lies almost at 73 ° N. sh. (and Henrietta Island in the De Long archipelago - even at 77 ° N); the southernmost regions in the Mai River basin reach 58°N. sh. Approximately half of the country's territory lies north of the Arctic Circle.

North-Eastern Siberia is a country with a varied and contrasting relief. Within its limits are mountain ranges and plateaus, and in the north - flat lowlands, stretching along the valleys of large rivers far to the south. All this territory belongs to the Verkhoyansk-Chukotka region of the Mesozoic folding. The main processes of folding took place here mainly in the second half of the Mesozoic, but the formation of the modern relief is mainly due to the latest tectonic movements.

The climate of the country is harsh, sharply continental. The amplitudes of absolute temperatures are in places 100-105°; in winter there are frosts down to -60 -68 °, and in summer the heat sometimes reaches 30-36 °. On the plains and in the low mountains of the country, there is little precipitation, and in the extreme northern regions their annual amount is as small as in the desert regions of Central Asia (100-150 mm). Permafrost is found everywhere, holding down soils to a depth of several hundred meters.

On the plains of northeastern Siberia, zonality is clearly expressed in the distribution of soils and vegetation: zones of arctic deserts (on islands), continental tundra and monotonous swampy larch woodlands are distinguished.

Altitude zoning is typical for mountainous regions. Sparse forests cover only the lower parts of the slopes of the ridges; their upper limit only in the south rises above 600-1000 m. Therefore, significant areas are occupied by mountain tundra and thickets of shrubs - alder, undersized birch and elfin cedar.

The first information about the nature of the Northeast was delivered in the middle of the 17th century. explorers Ivan Rebrov, Ivan Erastov and Mikhail Stadukhin. At the end of the XIX century. the expeditions of G. A. Maidel and I. D. Chersky conducted reconnaissance studies of mountainous regions, and the northern islands were studied by A. A. Bunge and E. V. Toll. However, information about the nature of the Northeast remained very incomplete until research in the Soviet era.

Expeditions of S. V. Obruchev in 1926 and 1929-1930. significantly changed the ideas even about the main features of the country's orography: the Chersky Range was discovered with a length of more than 1000 km, the Yukagir and Alazeya plateaus, the position of the sources of the Kolyma was clarified, etc. The discovery of large deposits of gold, and then other metals, necessitated geological research. As a result of the work of Yu. A. Bilibin, S. S. Smirnov, specialists from Dalstroy, the North-Eastern Geological Administration and the Arctic Institute, the main features of the geological structure of the territory were clarified and many mineral deposits were discovered, the development of which caused the construction of workers' settlements, roads and the development of shipping on the rivers.

At present, on the basis of aerial survey materials, detailed topographic maps have been compiled and the main geomorphological features of North-Eastern Siberia have been elucidated. New scientific data have been obtained as a result of studies of modern glaciation, climate, rivers and permafrost.

North-Eastern Siberia is a predominantly mountainous country; lowlands occupy a little more than 20% of its area. The most important orographic elements are the mountain systems of the marginal ranges Verkhoyansk and Kolyma highlands- form an arc convex to the south with a length of 4000 km. Inside it are chains elongated parallel to the Verkhoyansk system Chersky Ridge, ridges Tas-Khayakhtakh, Tas-Kystabyt (Sarychev), Momsky and etc.

The mountains of the Verkhoyansk system are separated from the Chersky ridge by a lowered strip Jansky, Elginsky and Oymyakon plateau. East located Nerskoye Plateau and Upper Kolyma Highlands, and in the southeast, the Verkhoyansk ridge adjoins the ridge Sette-Daban and the Yudomo-Maya Highlands.

The highest mountains are located in the south of the country. Their average height is 1500-2000 m, however, in the Verkhoyansk, Tas-Kystabyt, Suntar Khayata and Chersky, many peaks rise above 2300-2800 m, and the highest of them is Mount Pobeda in the ridge Ulakhan-Chistai- reaches 3147 m. The mid-mountain relief is replaced here by alpine peaks, steep rocky slopes, deep river valleys, in the upper reaches of which there are firn fields and glaciers.

In the northern half of the country, the mountain ranges are lower and many of them stretch in a direction close to meridional. Along with low ridges ( Kharaulakhsky, Selennyakhsky) there are flat ridge-like hills (ridge half-moustache, Ulakhan-Sis) and plateaus (Alazeyskoye, Yukagirskoe). A wide strip of the coast of the Laptev Sea and the East Siberian Sea is occupied by the Yano-Indigirskaya lowland, from which the intermountain Sredneindigirskaya (Abyiskaya) and Kolyma lowlands protrude far to the south along the valleys of the Indigirka, Alazeya and Kolyma. Most of the islands of the Arctic Ocean also have a predominantly flat relief.

Orographic scheme of North-Eastern Siberia

Geological structure and history of development

The territory of the current North-Eastern Siberia in the Paleozoic and the first half of the Mesozoic was a site of the Verkhoyansk-Chukotka geosynclinal marine basin. This is evidenced by the large thickness of the Paleozoic and Mesozoic deposits, in some places reaching 20-22 thousand km. m, and intensive manifestation of tectonic movements that created the folded structures of the country in the second half of the Mesozoic. Especially typical are deposits of the so-called Verkhoyansk complex, whose thickness reaches 12-15 thousand tons. m. It includes Permian, Triassic, and Jurassic sandstones and shales, usually intensely dislocated and intruded by young intrusions. In some areas, terrigenous rocks are interbedded with effusives and tuffs.

The most ancient structural elements are the Kolyma and Omolon median massifs. Their base is composed of Precambrian and Paleozoic sediments, and the Jurassic formations covering them, unlike other areas, consist of weakly dislocated carbonate rocks occurring almost horizontally; effusives also play a prominent role.

The remaining tectonic elements of the country are of younger age, predominantly Upper Jurassic (in the west) and Cretaceous (in the east). These include the Verkhoyansk folded zone and the Sette-Dabansky anticlinorium, the Yana and Indigirsko-Kolyma synclinal zones, as well as the Tas-Khayakhtakhsky and Momsky anticlinoria. The extreme northeastern regions are part of the Anyui-Chukotka anticline, which is separated from the median massifs by the Oloy tectonic depression filled with volcanic and terrigenous Jurassic deposits. Mesozoic fold-forming movements, as a result of which these structures were formed, were accompanied by ruptures, outpourings of acidic and basic rocks, intrusions, which are associated with various mineralization (gold, tin, molybdenum).

By the end of the Cretaceous, Northeastern Siberia was already a consolidated territory elevated above the neighboring regions. The processes of denudation of mountain ranges in the conditions of the warm climate of the Upper Cretaceous and Paleogene led to the leveling of the relief and the formation of flat surfaces of alignment, the remains of which have been preserved in many ranges.

The formation of modern mountain relief is due to differentiated tectonic uplifts of the Neogene and Quaternary time, the amplitude of which reached 1000-2000 m. In areas of the most intense uplifts, especially high ridges arose. Their strike usually corresponds to the direction of the Mesozoic structures, i.e., it is inherited; however, some ridges of the Kolyma Highlands are distinguished by a sharp discrepancy between the strike of folded structures and modern mountain ranges. Areas of Cenozoic subsidence are currently occupied by lowlands and intermountain basins filled with strata of loose deposits.

During the Pliocene the climate was warm and humid. On the slopes of the then low mountains there were coniferous-deciduous forests, which included oak, hornbeam, hazel, maple, and gray walnut. Among conifers, Californian forms prevailed: Western American mountain pine (Pinus monticola), Vollosovich spruce (Picea wollosowiczii), members of the family Taxodiaceae.

Early Quaternary uplifts were accompanied by a noticeable cooling of the climate. The forests that covered the southern regions of the country at that time consisted mainly of dark conifers, close to those currently found in the North American Cordillera and the mountains of Japan. From the middle of the Quaternary, glaciation began. Large valley glaciers appeared on the mountain ranges that continued to rise, and on the plains, where, according to D. M. Kolosov, glaciation was of an embryonic nature, firn fields formed. In the far north - in the archipelago of the New Siberian Islands and on the coastal lowlands - in the second half of the Quaternary, the formation of permafrost and ground ice began, the thickness of which in the cliffs of the Arctic Ocean reaches 50-60 m.

Thus, the glaciation of the plains of the Northeast was passive. Most of the glaciers were inactive formations; they carried some loose material, and their exaration effect had little effect on the relief.

Erosion valley in the low-mountain massif of the Tuora-sis ridge. Photo by O. Egorov

The traces of mountain-valley glaciation are much better expressed in the outlying mountain ranges, where well-preserved forms of glacial exaration are found in the form of kars and trough valleys, often crossing the watershed parts of the ridges. The length of valley glaciers descending in the Middle Quaternary from the western and southern slopes of the Verkhoyansk Range to neighboring areas of the Central Yakut Lowland reached 200-300 km. According to most researchers, there were three independent glaciations in the mountains of the Northeast: the Middle Quaternary (Tobychansky) and the Upper Quaternary - Elga and Bokhapcha.

The fossil flora of interglacial deposits testifies to the progressive increase in the severity and continentality of the country's climate. Already after the first glaciation, along with some North American species (for example, hemlock), Siberian conifers appeared in the composition of forest vegetation, including the Daurian larch that is now dominant.

During the second interglacial epoch, mountain taiga prevailed, which is now typical of the more southern regions of Yakutia; the vegetation of the time of the last glaciation, among which there were no dark coniferous trees, already differed little in species composition from the modern one. According to A.P. Vaskovsky, the firn line and the forest boundary then descended in the mountains by 400-500 m lower, and the northern limit of forest distribution was noticeably shifted to the south.

Main types of relief

The main relief types of North-Eastern Siberia form several distinct geomorphological tiers. The most important features of each of them are associated primarily with the hypsometric position, due to the nature and intensity of the latest tectonic movements. However, the location of the country in high latitudes and its severe, sharply continental climate determine the altitudinal limits of the distribution of the corresponding types of mountain relief, which are different from those in more southern countries. In addition, the processes of nivation, solifluction, and frost weathering are of greater importance in their formation. Forms of permafrost relief formation also play a significant role here, and fresh traces of Quaternary glaciation are characteristic even of plateaus and areas with low mountain relief.

In accordance with the morphogenetic features within the country, the following types of relief are distinguished: accumulative plains, erosion-denudation plains, plateaus, low mountains, mid-mountain and high-mountain alpine relief.

Accumulative plains occupy areas of tectonic subsidence and accumulation of loose Quaternary deposits - alluvial, lacustrine, marine and glacial. They are characterized by slightly rugged topography and slight fluctuations in relative heights. Forms that owe their origin to permafrost processes, large ice content of loose deposits and the presence of thick underground ice are widespread here: thermokarst basins, permafrost heaving mounds, frost cracks and polygons, and on the sea coasts, high ice cliffs are intensively collapsing (for example, the famous Oyegossky Yar with a length of more than 70 km).

Accumulative plains occupy vast areas of the Yano-Indigirskaya, Sredneindigirskaya and Kolyma lowlands, some islands of the seas of the Arctic Ocean ( Faddeevsky, Lyakhovsky, Land Bunge and etc.). Small areas of them are also found in depressions in the mountainous part of the country ( Momo-Selennyakhskaya and Seimchanskaya depressions, Yanskoye and Elga plateaus).

Erosion-denudation plains are located at the foot of some northern ranges (Anyuysky, Momsky, Kharaulakhsky, Kulara), on the peripheral sections of the Polousny ridge, the Ulakhan-Sis ridge, the Alazeysky and Yukagirsky plateaus, as well as on Kotelny Island. Their surface height usually does not exceed 200 m, but near the slopes of some ridges it reaches 400-500 m.

In contrast to the accumulative plains, these plains are composed of bedrock of various ages; the cover of loose sediments is usually thin. Therefore, rubble placers, sections of narrow valleys with rocky slopes, low hills prepared by denudation processes, as well as spots-medallions, solifluction terraces and other forms associated with the processes of permafrost relief formation are often found.

Plateau relief it is most typically expressed in a wide strip separating the systems of the Verkhoyansk Range and the Chersky Range (Yanskoye, Elginskoye, Oymyakonskoye and Nerskoye plateaus). It is also characteristic of the Upper Kolyma Highlands, the Yukagir and Alazeya Plateaus, large areas of which are covered with Upper Mesozoic effusive rocks, which occur almost horizontally. However, most of the plateaus are composed of folded Mesozoic deposits and represent denudation leveling surfaces currently located at an altitude of 400 to 1200-1300 m. In places, higher remnant massifs also rise above their surface, typical, for example, for the upper reaches of the Adycha and especially the Upper Kolyma Uplands, where numerous granite batholiths protrude in the form of high domed hills prepared by denudation. Many rivers in regions with a flat mountainous relief are mountainous in nature and flow in narrow rocky gorges.

Upper Kolyma Highlands. In the foreground is Jack London Lake. Photo by B. Vazhenin

lowlands occupy areas subjected in the Quaternary to uplifts of moderate amplitude (300-500 m). They are located mainly on the outskirts of high ridges and are dissected by a dense network of deep (up to 200-300 m) river valleys. The low mountains of North-Eastern Siberia are characterized by relief forms due to nival-solifluction and glacial processing, as well as an abundance of stony placers and rocky peaks.

Middle mountain relief is especially typical for most massifs of the Verkhoyansk Range, the Yudomo-Maya Uplands, the Chersky Range, Tas-Khayakhtakh and Momsky. Significant areas are occupied by mid-mountain massifs also in the Kolyma Uplands and the Anyui Range. Modern medium-altitude mountains arose as a result of the latest uplifts of denudation plains of leveling surfaces, some of which have been preserved here to this day. Then, in the Quaternary, the mountains were vigorously eroded by deep river valleys.

The height of the mid-mountain massifs - from 800-1000 to 2000-2200 m, and only at the bottom of deeply incised valleys do the marks sometimes drop to 300-400 m. Relatively gentle relief forms prevail in the interfluve spaces, and fluctuations in relative heights usually do not exceed 200-300 m. Forms created by Quaternary glaciers, as well as permafrost and solifluction processes, are widespread everywhere. The development and preservation of these forms is facilitated by the harsh climate, since, unlike the more southern mountainous countries, many mid-mountain massifs of the Northeast are located above the upper limit of woody vegetation, in the mountain tundra.

River valleys are quite diverse. Most often these are deep, sometimes canyon-like gorges (the depth of the Indigirka valley reaches, for example, 1500 m). However, the upper reaches of the valleys usually have a wide flat bottom and less high slopes.

High Alpine relief associated with areas of the most intense Quaternary uplifts, located at an altitude of more than 2000-2200 m. These include the crests of the highest ridges (Suntar-Khayata, Tas-Khayakhtakh, the Chersky Tas-Kystabyt ridge, Ulakhan-Chistai), as well as the central regions of the Verkhoyansk ridge. Due to the fact that the activity of Quaternary and modern glaciers played the most significant role in the formation of the alpine relief, it is characterized by deep dissection and large amplitudes of heights, the predominance of narrow rocky ridges, as well as cirques, cirques and other glacial landforms.

Climate

The harsh, sharply continental climate of North-Eastern Siberia is due to the fact that this country is located mainly within the Arctic and subarctic climatic zones, at a considerable height above sea level and is isolated by mountain ranges from the influences of the Pacific Ocean seas.

The total solar radiation per year, even in the south, does not exceed 80 kcal/cm 2. Radiation values ​​vary greatly by season: in December and January they are close to 0, in July they reach 12-16 kcal/cm 2. For seven to eight months (from September - October to April), the radiation balance of the earth's surface is negative, and in June and July it is 6-8 kcal/cm 2 .

Average annual temperatures are everywhere below -10°, and on the New Siberian Islands and in the highlands, even -15-16°. Such low temperatures are due to the long duration of winter (six to eight months) and its extreme severity.

Already in early October, an area of ​​increased pressure of the Asian anticyclone begins to form over North-Eastern Siberia. Throughout the winter, very cold continental air dominates here, formed mainly as a result of the transformation of Arctic air masses coming from the north. In conditions of cloudy weather, high dryness of the air and a short duration of daylight hours, an intensive cooling of the earth's surface occurs. Therefore, the winter months are characterized by extremely low temperatures and the absence of thaws. The average January temperatures are everywhere, except for the northern lowlands, below -38, -40°. The most severe frosts occur in intermountain basins, where stagnation and especially intense cooling of the air occur. It is in such places that Verkhoyansk and Oymyakon are located, which are considered the pole of cold in the northern hemisphere. Average January temperatures here are -48 -50°; on some days frosts reach -60 -65° (the minimum temperature observed in Oymyakon is -69.8°).

Mountainous regions are characterized by winter temperature inversions in the lower layer of air: the temperature rise with height reaches in some places 1.5-2° for every 100 m lift. For this reason, it is usually less cold on the slopes than at the bottom of intermountain basins. In places this difference reaches 15-20°. Such inversions are typical, for example, for the upper reaches of the Indigirka, where the average January temperature in the village of Agayakan, located at an altitude of 777 m, equal to -48 °, and in the mountains of Suntar-Khayat, at an altitude of 2063 m, rises to -29.5°.

Mountain ranges in the north of the Kolyma Highlands. Photo by O. Egorov

During the cold period of the year, relatively little precipitation falls - from 30 to 100-150 mm, which is 15-25% of their annual amount. In intermountain depressions, the thickness of the snow cover usually does not exceed 25 (Verkhoyansk) - 30 cm(Oymyakon). It is approximately the same in the tundra zone, but on the mountain ranges of the southern half of the country, the snow thickness reaches 50-100 cm. There are great differences between closed basins and the tops of mountain ranges in relation to the wind regime. Very weak winds prevail in the basins in winter, and calm weather is often observed for several weeks in a row. In especially severe frosts near settlements and highways, fogs are so thick that even in the daytime it is necessary to turn on the lights in houses and turn on headlights in cars. Unlike the basins, peaks and passes are often strong (up to 35-50 m/s) winds and blizzards.

Spring everywhere is short, friendly, with little rainfall. The spring month here is only May (in the mountains - the beginning of June). At this time, the sun shines brightly, daily air temperatures rise above 0 °, the snow melts quickly. True, at night in early May there are still frosts down to -25, -30 °, but by the end of the month the maximum air temperatures during the day sometimes reach 26-28 °.

After a short spring comes a short but relatively warm summer. At this time, low pressure is established over the mainland of the country, and higher pressure over the northern seas. Located near the northern coast, the Arctic front separates the masses of warm continental air and colder air that forms over the surface of the seas of the Arctic Ocean. The cyclones associated with this front often break south, into the coastal plains, causing a noticeable drop in temperature and precipitation. The warmest summer is in the intermountain depressions of the upper reaches of the Yana, Indigirka and Kolyma. The average July temperature here is about 14-16°, on some days it rises to 32-35°, and the soil warms up to 40-50°. However, it is cold at night, and frosts are possible in any summer month. Therefore, the duration of the frost-free period does not exceed 50-70 days, although the sum of positive average daily temperatures reaches 1200-1650 ° during the summer months. In the northern tundra regions and on mountain ranges rising above the treeline, summers are cooler and the average temperature in July is below 10-12°.

During the summer months, the main amount of precipitation falls (65-75% of the annual amount). Most of them come with air masses coming in July and August from the west, northwest and north. The greatest amount of precipitation falls on the Verkhoyansk and Chersky ridges, where at altitudes of 1000-2000 m during the summer months their sum reaches 400-600 mm; much less of them in areas of flat tundra (150-200 mm). There is very little precipitation in closed intermountain basins (Verkhoyansk - 80 mm, Oymyakon - 100 mm, Seymchan - 115 mm), where, due to dry air, high temperatures and significant evaporation, the vegetation of plants occurs under conditions of a noticeable lack of moisture in the soil.

The first snowfalls are possible already at the end of August. September and the first half of October can still be considered autumn months. In September, there are often clear, warm and windless days, although frosts are already common at night. At the end of September, the average daily temperatures drop below 0°, frosts at night in the north reach -15 -18°, blizzards often occur.

Permafrost and glaciation

The harsh climate of the country causes intense freezing of rocks and the continuous spread of permafrost, which has a significant impact on the formation of landscapes. Northeastern Siberia is distinguished by a very large thickness of permafrost, which in places in the northern and central regions is more than 500 m, and in most mountainous areas - from 200 to 400 m. Very low temperatures of the rock mass are also characteristic. At the bottom of the layer of annual temperature fluctuations, located at a depth of 8-12 m, they rarely rise above -5 -8°, and within the coastal plain -9 -10°. The depth of the seasonal thawing horizon ranges from 0.2-0.5 m in the north up to 1-1.5 m on South.

On the lowlands and in intermountain depressions, underground ice is widespread - both syngenetic, formed simultaneously with the host rocks, and epigenetic, formed in rocks deposited earlier. Especially typical for the country are syngenetic polygonal vein ice, which form the largest accumulations of underground ice. On the coastal lowlands, their thickness reaches 40-50 m, and on Bolshoi Lyakhovsky Island - even 70-80 m. Some ices of this type can be considered "fossils", since their formation began as early as the Middle Quaternary.

Underground ice has a significant impact on the formation of the relief, the regime of rivers and the conditions for the economic activity of the population. So, for example, the processes of ice melting are associated with the phenomena of flow and subsidence of soils, as well as the formation of thermokarst basins.

The climatic conditions of the country's highest ranges contribute to the formation of glaciers. In places here at an altitude of more than 2000-2500 m drops up to 700-1000 mm/year sediments, most of them in solid form. Snow melting occurs only during two summer months, which are also characterized by significant cloudiness, low temperatures (the average temperature in July is from 3 to 6-7 °) and frequent night frosts. More than 650 glaciers with a total area of ​​over 380 km 2. The centers of the most significant glaciation are located in the Suntar-Khayat ridge and in Buordakh massif. The snow line lies high here - at elevations from 2100 to 2600 m, which is explained by the predominance of a fairly continental climate even at these altitudes.

Most of the glaciers occupies the slopes of the northern, northwestern and northeastern exposure. Among them, car and hanging ones predominate. There are also firn glaciers and large snowfields. However, all the largest glaciers are valley ones; their tongues descend to a height of 1800-2100 m. The maximum length of these glaciers reaches 6-7 km, area - 20 km 2 , and the ice power is 100-150 m. Almost all glaciers in the Northeast are now in retreat.

Rivers and lakes

Northeastern Siberia is dissected by a network of many rivers flowing to the Laptev and East Siberian seas. The largest on them - Yana, Indigirka and Kolyma - flow almost in a meridional direction from south to north. Cutting through mountain ranges in narrow deep valleys and receiving numerous tributaries here, they, already in the form of high-water streams, go to the northern lowlands, where they acquire the character of flat rivers.

In terms of their regime, most of the country's rivers belong to the East Siberian type. They feed mainly on melting snow cover in early summer and summer rains. A certain role in the nutrition of rivers is played by groundwater and the melting of "eternal" snow and glaciers in high mountains, as well as icing, the number of which, according to O. N. Tolstikhin, exceeds 2700, and their total area is 5762 km 2. More than 70% of the annual river flow falls on three calendar summer months.

Freezing on the rivers of the tundra zone begins already in late September - early October; mountain rivers freeze at the end of October. In winter, ice forms on many rivers, and small rivers freeze to the bottom. Even on such large rivers as the Yana, Indigirka, Alazeya and Kolyma, the runoff during the winter is from 1 to 5% per annum.

Ice drift begins in the last decade of May - early June. At this time, most rivers have the highest water levels. In some places (for example, in the lower reaches of the Yana), as a result of ice jams, the water sometimes rises by 15-16 m above winter levels. During the flood period, the rivers intensively erode their banks and clutter up the channels with tree trunks, forming numerous creases.

The largest river in North-Eastern Siberia - Kolyma(basin area - 643 thousand sq. km 2 , length - 2129 km) - begins in the Upper Kolyma Highlands. Somewhat below the mouth of the Korkodon River, the Kolyma enters the Kolyma Lowland; its valley widens sharply here, the fall and speed of the current decrease, and the river gradually acquires a flat appearance. Near Nizhnekolymsk, the width of the river reaches 2-3 km, and the average annual consumption is 3900 m 3 /sec(for a year, Kolyma takes out to the East Siberian Sea about 123 km 3 water). At the end of May, a high spring flood begins, but by the end of June, the flow of the river decreases. Summer rains cause a number of less significant floods and provide a fairly high level of the river until the onset of freeze-up. The distribution of the Kolyma runoff in its lower reaches is as follows: in spring - 48%, in summer - 36%, in autumn - 11% and in winter - 5%.

Sources of the second major river - Indigirki(length - 1980 km, the basin area is over 360 thousand sq. km 2) - located in the area of ​​the Oymyakon Plateau. Crossing the Chersky Range, it flows in a deep (up to 1500-2000 m) and a narrow valley with almost steep slopes; rapids are often found here in the channel of the Indigirka. Near the village of Krest-Mayor, the river enters the plain of the Sredneindigirskaya lowland, where it breaks into branches separated by sandy islands. Below the village of Chokurdakh, the delta begins, the area of ​​\u200b\u200bwhich is about 7700 km 2. In the feeding of the river, the most prominent role is played by summer rains (78%), melted snow (17%), and in the upper reaches - glacial waters. Indigirka annually brings to the Laptev Sea about 57 km 3 water (its average annual consumption is 1800 m 3 /sec). The main runoff (about 85%) falls on summer and spring.

Lake of Dancing Graylings. Photo by B. Vazhenin

The western regions of the country are drained by Yana (length - 1490 km 2, basin area - 238 thousand sq. km 2). Its sources - the Dulgalakh and Sartang rivers - flow down from the northern slope of the Verkhoyansk Range. After their confluence within the Yan Plateau, the river flows in a wide valley with well-developed terraces. In the middle part of the current, where the Yana crosses the spurs of the mountain ranges, its valley narrows, and rapids appear in the channel. The lower reaches of the Yana are located on the territory of the coastal lowland; at its confluence with the Laptev Sea, the river forms a large delta (with an area of ​​about 5200 km 2).

The Yana belongs to the rivers of the Far Eastern type and is characterized by a long summer flood, which is due to the gradual melting of the snow cover in the mountainous regions of its basin and the abundance of summer rains. The highest water levels are observed in July and August. The average annual consumption is 1000 m 3 /sec, and the stock for the year is over 31 km 3 , of which more than 80% occur in summer and spring. Yana's expenses vary from 15 m 3 /sec in winter up to 9000 m 3 /sec during the summer flood.

Most of the lakes of North-Eastern Siberia are located on the northern plains, in the basins of the Indigirka and Alazeya. Here there are places where the area of ​​the lakes is not less than the area of ​​the land separating them. The abundance of lakes, of which there are several tens of thousands, is due to the small ruggedness of the lowland relief, difficult runoff conditions, and the widespread permafrost. Most often, lakes occupy thermokarst basins or depressions in floodplains and on river islands. All of them are distinguished by their small size, flat banks, shallow depths (up to 4-7 m). For seven to eight months, the lakes are bound by a powerful ice cover; very many of them freeze to the bottom in the middle of winter.

Vegetation and soils

In accordance with the harsh climatic conditions in the territory of North-Eastern Siberia, landscapes of northern taiga sparse forests and tundra prevail. Their distribution depends on the geographical latitude and height of the area above sea level.

In the far north, on the islands of the Arctic Ocean, arctic deserts with poor vegetation on primitive thin arctic soils. To the south, on the mainland coastal plain, is located tundra zone- arctic, hummocky and shrubby. Here, gleyed tundra soils are formed, which are also thin. Only to the south of 69-70 ° N. sh. on the tundra plains of the Yano-Indigirka and Kolyma lowlands in the river valleys, the first groups of undersized and oppressed Dahurian larch appear.

In the more southern regions, on the Sredne-Indigirskaya and Kolyma lowlands, such copses emerge from the valleys to the interfluves, forming either larch “gap forests” or very monotonous sparse low-grade forests of the northern taiga appearance on gley-frozen-taiga soils.

Sparse larch forests usually occupy the lower parts of the mountain slopes. Under a sparse cover of low (up to 10 - 15 m) larches are thickets of undersized shrubs - birches (skinny - Betula exilis, shrub - B. fruticosa and Middendorf - B. middendorffii), alder (Alnaster fruticosus), juniper (Juniperus sibirica), rhododendrons (Rhododendron parvifolium and R. adamsii), various willows (Salix xerophila, S. glauca, S. lanata)- or the soil is covered with an almost continuous carpet of mosses and bushy lichens - cladonia and cetraria. Sparse forests are dominated by peculiar mountain taiga-frozen soils with an acidic reaction and without clearly defined genetic horizons (with the exception of the humus one). The features of these soils are associated with shallow permafrost, low temperatures, low evaporation, and the development of permafrost phenomena in the soil. In summer, such soils experience temporary waterlogging, which causes their weak aeration and the appearance of signs of gleying.

The mountains of North-Eastern Siberia are characterized by low vertical limits of distribution of tree species. The upper limit of woody vegetation is located at a height of only 600-700 m, and in the extreme northern mountainous regions it does not rise above 200-400 m. Only in the southernmost regions - in the upper reaches of the Yana and Indigirka, as well as in the Yudomo-Maya Highlands - larch forests occasionally reach 1100-1400 m.

They differ sharply from the monotonous light forests of the mountain slopes of the forests that occupy the bottom of deep river valleys. Valley forests develop on well-drained alluvial soils and consist mainly of fragrant poplar (Populus suaveolens), whose height reaches 25 m, and the thickness of the trunk - 40-50 cm, and Chosenia (Chosenia macrolepis), which has a direct high (up to 20 m), but thin (20-30 cm) trunk.

Above the mountain-taiga zone on the slopes are dense thickets of Siberian dwarf pine (Pinus pumila) or alder forest, gradually changing into a zone mountain tundra, in which in some places there are small areas of sedge-cereal alpine meadows. Tundra occupies approximately 30% of the area of ​​mountainous regions.

The crests of the highest massifs, where climatic conditions prevent the existence of even the most unpretentious plants, are a lifeless cold desert and are covered with a continuous cloak of stone placers and screes, over which rocky peaks rise.

Animal world

The fauna of North-Eastern Siberia differs markedly from the fauna of the neighboring regions of Siberia. To the east of the Lena, some animals common to the Siberian taiga disappear. There is no Siberian weasel, Siberian ibex, etc. Instead of them, mammals and birds appear in the mountains and on the plains, close to those widely distributed in North America. Of the 45 species of mammals living in the mountains of the Kolyma basin, more than half are very closely related to the animals of Alaska. Such, for example, are the yellow-bellied lemming (Lemmus chrysogaster), light wolf, huge Kolyma elk (Alces americanus). Some American fish are found in the rivers (for example, dallium - Dallia pectoralis, Chukuchan - catostomus catostomus). The presence of North American animals in the composition of the fauna of the Northeast is explained by the fact that even in the middle of the Quaternary, there was land on the site of the current Bering Strait, which sank only in the Upper Quaternary.

Another characteristic feature of the country's fauna is the presence of steppe animals in its composition, which are not found anywhere else in the far north. In the high-mountainous rocky tundra, one can often meet the Verkhoyansk black-capped marmot - tarbagan (Marmota camtschatica), and on the dry glades of the mountain taiga zone - the long-tailed Kolyma ground squirrel (Citellus undulatus buxtoni). During the winter, which lasts at least seven to eight months, they sleep in their burrows in the frozen ground. The closest relatives of the black-capped marmot, as well as the bighorn sheep (Ovis nivicola) live in the mountains of Central Asia and Transbaikalia.

The study of the remains of fossil animals found in the Middle Quaternary deposits of North-Eastern Siberia shows that even then the woolly rhinoceros and reindeer, musk ox and wolverine, tarbagan and arctic fox lived here - animals of regions with a very continental climate, close to the modern climate of the highlands of Central Asia . According to zoogeographers, within the boundaries of ancient Beringia, which included the territory of the North-East of the USSR, the formation of modern taiga fauna began in the Quaternary. It was based on: 1) local species adapted to the cold climate; 2) immigrants from North America; and 3) immigrants from the mountains of Central Asia.

Mammals in the mountains are now dominated by various small rodents and shrews; there are more than 20 species of them. Of the predators, the large Beringian bear, wolverine, East Siberian lynx, arctic fox, Beringian fox are characteristic, there are also sable, weasel, ermine and East Siberian wolf. Among the birds are typical stone capercaillie (Tetrao urogalloides), hazel grouse (Tetrastes bonasia kolymensis), nutcracker (Nucifraga caryocatactes), ptarmigan (Lagopus mutus), Asiatic ash snail (Heteractitis incana). In summer, many waterfowl are found on the lakes: scoter (Oidemia fusca), bean goose (Anser fabalis) and etc.

Snow sheep. Photo by O. Egorov

Natural resources

Of the natural resources of North-Eastern Siberia, minerals are of the greatest importance; especially important are ore deposits associated with Mesozoic intrusive rocks.

In the mountains of the Yano-Kolyma Territory, which are part of the Pacific metallogenic belt, there are well-known gold-bearing regions - Verkhneindigirsky, Allah-Yunsky and Yansky. A large tin-bearing province has been explored within the Yana-Indigirka interfluve. The largest deposits of tin - Deputatskoe, Ege-Khaiskoe, Kesterskoe, Ilintas, etc. - are associated with the Upper Jurassic and Cretaceous granite intrusions; a lot of tin is also found here in alluvial placers. The deposits of polymetals, tungsten, mercury, molybdenum, antimony, cobalt, arsenic, coal and various building materials are also of significant importance. In recent years, prospects for the discovery of oil and gas fields have been identified in intermountain depressions and on coastal lowlands.

Dredging on one of the rivers of the Upper Kolyma Highlands. Photo by K. Kosmachev

Large rivers of North-Eastern Siberia are navigable for a long distance. The total length of currently operated waterways is about 6000 km(of which in the Kolyma basin - 3580 km, Yany - 1280 km, Indigirki - 1120 km). The most significant shortcomings of rivers as means of communication are a short (only three months) navigation period, as well as an abundance of rapids and riffles. Hydropower resources are also significant here (Indigirka - 6 mln. kW, Yana - 3 million. kW), but their use is difficult due to the exceptionally large fluctuations in the water content of the rivers according to the seasons of the year, freezing in winter and the abundance of inland ice. The engineering-geological conditions for the construction of structures on permafrost are also complex. At present, the Kolyma hydroelectric power station, the first in the Northeast, is being built in the upper reaches of the Kolyma.

In contrast to other Siberian countries, the reserves of high-quality timber are relatively small here, since the forests are usually sparse and their productivity is low. The average stock of timber in the forests of even the most developed southeastern regions is no more than 50-80 m 3 /ha.

The harsh climate also limits the possibilities for the development of agriculture. In the tundra zone, where the sum of average daily temperatures above 10° even in the south barely reaches 600°, only radishes, lettuce, spinach and onions can be grown. To the south, turnips, turnips, cabbage, and potatoes are also cultivated. In especially favorable conditions, mainly on the gentle slopes of the southern exposure, it is possible to sow early varieties of oats. More favorable conditions for animal husbandry. Significant areas of the plain and mountain tundra are good reindeer pastures, and the meadows of the river valleys serve as a food base for cattle and horses.

Before the Great October Revolution, North-Eastern Siberia was the most backward outskirts of Russia. The development of its natural resources and all-round development began only in the conditions of a socialist society. Widespread exploration work led to the discovery of ore deposits in the upper reaches of the Kolyma and Yana and the emergence of numerous mines and large workers' settlements here. Good highways were laid through the mountain ranges, and boats and steamboats appeared on the large rivers of the region. The mining industry has now become the basis of the economy and provides the country with many valuable metals.

Agriculture has also made some progress. The state farms set up in the upper reaches of the Indigirka and Kolyma meet part of the population's needs for fresh vegetables, milk and meat. In the Yakut collective farms of the northern and mountainous regions, reindeer breeding, fur trade and fishing are developing, giving significant marketable products. Horse breeding is also developed in some mountainous regions.

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Part Central and North-Eastern Siberia includes the entire territory of Siberia, lying east of the Yenisei. The Yenisei valley serves as a frontier, beyond which the structure of the subsoil, the relief, the climate, the water regime of the rivers, and the nature of the soil and vegetation cover change. In contrast to Western Siberia, elevated areas of plateaus and mountains prevail here. Therefore, the eastern part of our country is called High Siberia.

The eastern half of Russia is under the influence of the Pacific lithospheric plate, which is moving under the Eurasian continent. As a result, significant uplifts of the earth's crust took place here in the Mesozoic and Neogene-Quaternary times. Moreover, they covered the most diverse in structure and age tectonic structures - the Siberian platform with its ancient basement, the Baikalides, as well as Mesozoic folded structures of the Northeast. In the Neogene-Quaternary time, the Central Siberian Plateau was formed. Some sections of the ancient foundation of the platform turned out to be highly elevated, for example, the Anabar Plateau and the Yenisei Ridge. Between them was the Tunguska depression of the foundation. But it also rose in modern times and the Putorana Mountains formed in its place. On the Taimyr Peninsula, the revived Byrranga mountains arose, in the North-East - rejuvenated mountains: the Verkhoyansk Range, the Chersky Mountains and the Koryak Upland. Lowlands occupy in Central Siberia troughs between mountains and uplands (Vilyuiskaya and North Siberian) or the lowered northern edge of the Eurasian continent (Yano-Indigirskaya and Kolyma).

Uplifts of hard sections of the earth's crust were accompanied by numerous faults. The igneous masses intruded along the faults into the bowels of the platform, in some places they poured out onto the surface. The erupted magma solidified, forming lava plateaus.

Deposits of iron and copper-nickel ores and platinum are associated with outcrops of crystalline rocks of the basement. The largest coal deposits are located in tectonic troughs. Among them stands out the largest coal basin in the country - Tunguska. Coals are mined in the south of Yakutia, where the railway line from BAM is connected. Many minerals are associated with intrusions and outpourings of magmas. In sedimentary rocks, under their influence, in a number of places, coals turned into graphite. In the areas of ancient volcanism, the so-called explosion pipes were formed, to which the diamond deposits of Yakutia are confined. In the Northeast, deposits of tin ores and gold are associated with volcanic processes of past geological epochs. The sedimentary strata of the Lena-Vilyui and North Siberian lowlands contain hard and brown coal, oil and gas.

The climate throughout Central Siberia is sharply continental with long and very cold winters. A significant part of the territory is located in the arctic and subarctic climatic zones. Here is located cold pole of the northern hemisphere. In winter, stable, cloudy weather with severe frosts prevails. In the intermountain basins, where heavy cold air stagnates, the average January temperature drops to -40...-50°C. In the region of Verkhoyansk and Oymyakon, the coldest place in our country (the Pole of Cold) is located, with a temperature of -71°C recorded here. But windless dry weather helps the population endure these severe frosts. In summer, it is cloudy and the land is very hot. On the plains of central Yakutia, the average temperature in July reaches +19°C, it can rise up to +30°C and even up to +38°C. In summer, the weather is clear and hot for several weeks. In connection with the heating of the land over Central Siberia in the summer, a reduced atmospheric pressure is established, and air rushes here from the Arctic and Pacific oceans. Along the northern coasts, the Arctic climatic front (its Pacific branch) is established, so in summer cloudy, cool weather with rains and snowfalls prevails in these areas. The abundance of moisture leads to the formation of glaciers and snowfields in the mountains. They are most widely developed in the south of the Chersky Ridge.

In most of Central Siberia, permafrost up to 1 km or more in the north has been preserved since the glacial period. In winter, ice forms on many rivers, especially in the basins of the Yana, Indigirka and Kolyma rivers, some rivers freeze to the bottom.

A number of large rivers flow through Central Siberia - the Lena, the tributaries of the Yenisei - the Lower Tunguska, Podkamennaya Tunguska and Angara, in the northeast - the Yana, Indigirka and Kolyma rivers. All rivers originate in the mountains of the extreme south and east of the country, where relatively much precipitation falls, and carry water to the seas of the Arctic Ocean. On their way, they cross faults in the earth's crust, so their valleys often have the character of gorges with numerous rapids. Central Siberia has huge reserves of hydropower, some of which is already in use. The Irkutsk, Bratsk, and Ust-Ilim hydroelectric power plants were built on the Angara, the Vilyui hydroelectric power station operates on the Vilyui, and the Sayano-Shushenskaya hydroelectric power station operates on the Yenisei.

Most of Central Siberia is covered with light coniferous larch forests. She sheds her needles for the winter. This protects it from freezing during severe frosts. The superficial root system allows larch to grow using thawed soil layers in summer. Pine forests grow along the valleys of the Angara and Lena, where the frozen strata are covered with thick alluvial deposits. Taiga-permafrost soils are formed under all forests. The lower parts of the mountain slopes are covered with larch forests, which in the upper parts are replaced by dwarf pine and mountain tundra. Many peaks and high parts of the slopes are occupied by rocky deserts. The northern plains are dominated by tundra and forest-tundra.

In the forests of Central Siberia, there are many fur-bearing animals, the fur of which is highly valued. In harsh climates, it becomes very lush and soft. The most common hunting animals include squirrel, sable, ermine, marten, Siberian weasel and otter.

Mountains of Southern Siberia

Along the southern borders of Russia from the Irtysh to the Amur region, one of the largest mountain belts in the world stretches up to 4.5 thousand km. It consists of the Altai Mountains, the Western and Eastern Sayan, the Baikal region, the uplands of Transbaikalia, the Stanovoy Range and the Aldan Highlands. Mountains formed within a giant geosynclinal zone. It arose as a result of the interaction of large blocks of the earth's crust - the Chinese and Siberian platforms. These platforms are part of the Eurasian lithospheric plate and experience significant horizontal displacements, which in the zone of their contact are accompanied by crushing into folds of sedimentary rocks and the formation of mountains, fractures of the earth's crust and the introduction of granite intrusions, earthquakes, and the formation of various (ore and non-metallic) mineral deposits. The mountains were formed during the epochs of the Baikal, Caledonian and Hercynian folding. During the Paleozoic and Mesozoic, mountain structures were destroyed and leveled. The detrital material was transported to intermountain basins, where thick strata of black and brown coals simultaneously accumulated. In the Neogene-Quaternary time, as a result of intensive movements of the masses of the earth's crust, large deep faults were formed. Large intermountain basins arose in the lowered areas - Minusinsk, Kuznetsk, Baikal, Tuva, on elevated - medium-altitude and partially high mountains. The highest Altai mountains, where the highest point of all Siberia is Mount Belukha (4506 m). Thus, all the mountains of Southern Siberia are epiplatform folded-block regenerated. Vertical and horizontal movements of the earth's crust continue, so this entire belt belongs to the seismic regions of Russia, where the magnitude of earthquakes can reach 5-7 points. Particularly strong earthquakes occur in the region lake Baikal.

The tectonic movements of the earth's crust were accompanied by the processes of magmatism and metamorphism, which led to the formation of large deposits of various ores - iron and polymetallic in Altai, copper and gold in Transbaikalia.

The entire mountain system is located in the depths of the mainland, so its climate is continental. Continentality increases to the east, as well as along the southern slopes of the mountains. The windward slopes receive heavy rainfall. There are especially many of them on the western slopes of Altai (about 2000 mm per year). Therefore, its peaks are covered with snow and glaciers, the largest in Siberia. On the eastern slopes of the mountains, as well as in the mountains of Transbaikalia, the amount of precipitation decreases to 300-500 mm per year. Even less precipitation in the intermountain basins.

In winter, almost all mountains Southern Siberia affected by the Asian High Pressure. The weather is cloudless, sunny, with low temperatures. It is especially cold in the intermountain basins, in which the heavy air flowing down from the mountains stagnates. The temperature in winter in the basins drops to -50...-60°С. Altai stands out against this background. Cyclones often penetrate here from the west, accompanied by significant cloudiness and snowfalls. Clouds protect the surface from cooling. As a result, Altai winters differ from other areas of Siberia in their great softness and abundance of precipitation. Summer in most of the mountains is short and cool. However, in the basins it is usually dry and hot with an average July temperature of +20°C.

In general, the mountains of Southern Siberia are an accumulator within the arid continental plains of Eurasia. Therefore, the largest rivers of Siberia - the Irtysh, Biya and Katun - the sources of the Ob, originate in them; Yenisei, Lena, Vitim, Shilka and Argun are the sources of the Amur.

The rivers flowing down from the mountains are rich in hydropower. Mountain rivers fill with water lakes located in deep basins, and above all the largest and most beautiful lakes in Siberia - Baikal and Teletskoye.

54 rivers flow into Baikal, and one Angara flows out. In its deepest lake basin in the world, gigantic reserves of fresh water are concentrated. The volume of its waters is equal to the entire Baltic Sea and makes up 20% of the world and 80% of the internal volumes of fresh water. Baikal water is very clean and transparent. It can be used for drinking without any purification and processing. About 800 species of animals and plants live in the lake, including such valuable commercial fish as omul and grayling. Seals also live in Baikal. At present, a number of large industrial enterprises and cities have been built on the banks of Lake Baikal and the rivers flowing into it. As a result, the unique qualities of its waters began to deteriorate. In accordance with government decisions, a number of measures are being taken to protect nature in the lake basin in order to maintain the cleanliness of the reservoir.

Differences in temperatures and in the degree of moistening of the mountain slopes are directly reflected in the nature of the soil and vegetation cover of the mountains, in the manifestation of altitudinal zonality. Steppes rise along the slopes of Altai to a height of 500 m in the north and 1500 m in the south. In the past, feather grass and forb steppes were also located along the bottom of intermountain basins. Now the fertile chernozems of the steppe basins are almost completely plowed up. Above the steppe belt, on the damp western slopes of Altai, there are spruce-fir forests with an admixture of cedar. In drier Sayans, Baikal mountains and Transbaikalia dominated by pine-larch forests. Mountain-taiga permafrost soils have formed under the forests. The upper part of the forest belt is occupied by dwarf pine. In Transbaikalia and Aldan Highlands the forest zone almost entirely consists of shrub thickets of Siberian dwarf pine. Above the forests in Altai are subalpine and alpine meadows. In the Sayan mountains, on the Baikal and Aldan highlands, where it is much colder, the upper parts of the mountains are occupied by mountain tundra with dwarf birch.

Far East

The territory of the Far East stretches along the coast of the Pacific Ocean for 4500 km. It is located in the zone of contrasting processes and phenomena. As already noted, heterogeneous blocks of the earth's crust, various air masses, cold and warm sea currents interact here, representatives of the northern and southern flora and fauna coexist nearby. All this determines the great diversity of natural conditions.

The Far East is located in the zone of interaction of large lithospheric plates. The Pacific plate is moving under the continental Eurasian one. This is reflected in many features of nature. So, almost all mountain structures stretch parallel to the Pacific coast. Curved towards the continent ridges of the Koryak Highlands and The median ridge of Kamchatka. The southern outer arc of mountain structures is curved towards the ocean and consists of Eastern Range of Kamchatka and ridges of the Kuril Islands. These islands are the peaks of the highest (about 7000 m) mountains rising from the bottom of the sea. Most of them are under water. Most of the mountain structures of the Far East were formed in the Mesozoic. Powerful mountain-building processes and shifts of lithospheric plates continue. Evidence is intense earthquakes and seaquakes, the centers of which are located both in the bowels of mountain structures, and at the bottom of sea basins and deep-sea depressions - gutters. Seaquakes are accompanied by the formation of giant waves - tsunamis, which rapidly fall on the Far East coast, causing catastrophic destruction. The arcuate ridges also include volcanic mountains. The largest of them, Klyuchevskaya Sopka (4750 m), systematically ejects ash and lava. Volcanic processes are accompanied by geysers and numerous sources of thermal waters. In Kamchatka, they are used for heating buildings and greenhouses, and for generating electricity. Many mountains of the Far East are composed of hardened lavas, tuffs, pumice and other volcanic rocks.

In the south, there are mountains, highlands and plateaus formed as a result of the build-up of the continental lithospheric plate from the east at the expense of the oceanic one. Therefore, the western parts of the mountain structures are composed of more ancient folds than the eastern ones. So, Sikhote-Alin from the west it consists of Mesozoic folded structures, and from the east - Cenozoic. Sakhalin mountains are completely represented by Cenozoic folded structures of the earth's crust. The intrusion of igneous rocks into sedimentary strata led to the formation of deposits of iron, polymetallic and tin ores. Sedimentary rocks contain deposits of coal, oil and gas.

The climate of the entire Far East is determined by the interaction of continental and maritime air masses of temperate latitudes. In winter, currents of cold air rush to the southeast from the powerful Asian High. Therefore, the winter in the Far East is very severe and dry. In the northeast, along the edge of the Aleutian Low, the cold continental air of Eastern Siberia interacts with the relatively warm sea air. As a result, cyclones often occur, which are associated with a large amount of precipitation. There is a lot of snow in Kamchatka, blizzards are not uncommon. On the eastern coast of the peninsula, the height of the snow cover in some places can reach 3 m. Snowfalls are also significant on Sakhalin.

In summer, air currents rush from the Pacific Ocean. Maritime air masses interact with continental air masses, as a result of which monsoon rains occur throughout the Far East in summer. As a result, the largest Far Eastern river, the Amur, and its tributaries flood not in the spring, but in the summer, which usually leads to catastrophic floods. Devastating typhoons often sweep over coastal areas, coming from the southern seas.

The interaction of continental and marine air masses, northern and southern currents, a complex relief that combines mountains and lowlands, closed basins - all this together leads to a diversity of the vegetation cover of the Far East, to the presence of northern and southern species in its composition. In the northern lowlands there are tundras, into which larch forests enter from the south along the rivers. Most of Kamchatka is occupied by sparse forests of stone birch and larch, and thickets of dwarf pine with alder and lichens grow on the slopes of the mountains. Northern Sakhalin is characterized by sparse larch forests, while southern Sakhalin is characterized by impenetrable bamboo thickets and spruce-fir taiga. On the Kuril Islands, in Primorye and the Amur Region, where the summer is warm and humid, coniferous-broad-leaved forests of a rich species composition grow. They consist of Korean cedar, spruce, fir, linden, hornbeam, Manchurian walnut, pear and many other species. Dense thickets of trees are intertwined with vines, grapes and lemongrass. There are many medicinal herbs in the forests, including ginseng.

Northern and southern species of animals are found in the Amur and Primorye regions. Here live such Siberian species as reindeer, elk, sable, squirrel, and such southern species as the Amur tiger, spotted deer, black deer, raccoon dog. The Kuril Islands are characterized by seals, fur seals and sea otters.

In most of the Far East, agriculture is difficult. But on the southern plains with fertile chernozem-like and brown forest soils, wheat, rice, soybeans, potatoes and vegetables are grown.

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