Arctic basin (geology and morphology). The meaning of the arctic basin in the big encyclopedic dictionary What is the arctic basin

arctic basin

ARCTIC BASIN (Polar Basin) deep-water part of the North. Arctic approx., bounded from the south by the edge of the shelf of Eurasia and North. America. 5.3 million km2. It is dissected by the Gakkel, Lomonosov and Mendeleev underwater ridges into the Nansen, Amundsen, Makarov, Canadian and other basins. Drifting ice is characteristic. It is studied mainly by drifting stations "North Pole".

arctic basin

Polar Basin, Central Arctic Basin, deep-water part of the Arctic Ocean, bounded from the south by the edge of the continental shelf of Eurasia and the North. America. Area approx. 5.3 million km2. A. b. divided by 3 underwater ridges - Gakkel (minimum depth 400 m), Lomonosov (954 m), Mendeleev and uplifts (Alpha and Chukotsky) into underwater basins: Nansen (maximum depth 5449 m), Amundsen (4321 m), Makarov (3940 m) , Podvodnikov (3285 m), Toll (2780 l1), Kanadskaya (3838 m) and North Pole (2288 m). The bottom is covered with a layer of silt with a thickness of 0.5 to 2.5 km. The climate is harsh. The average temperature in January is from ≈30 to ≈34╟С, in July approx. 0╟С. Thus, A. b. all year round it is covered with close-knit drifting ice, mostly multi-year ones (“pak”). Surface water temperature approx. ≈1.8╟С, salinity is reduced by river runoff and summer ice melting to 30≈32┴. This layer is underlain by denser, warm Atlantic waters, which sink northward from Spitsbergen and spread throughout the Atlantic Ocean. at depths from 150≈200 m to 800 m. Their temperature is approx. 1╟С, salinity 34.5┴ and more. In the eastern part of A. b. at depths of 50 to 100 m, Pacific waters spread, which come from the Bering Sea and can be traced to the Lomonosov Ridge. Their temperature is approx.≈1.4╟С, salinity is approx. 33┴. Below 800 m A. b. occupied by bottom water with a temperature of approx. ≈1╟С and salinity over 34.5┴. The circulation of water and ice is determined by wind and water exchange with the Atlantic and Pacific oceans. In the Canadian region A. b. a stable anticyclonic circulation of ice and surface waters develops. In the rest of A. b. the flow of ice and waters of the Transarctic Current, directed from the Bering Sea to Greenland, dominates. Average drift velocities of ice and constant currents A. b. are 2≈4 km/day. In the waters of A. b. 70 species of phytoplankton were found, among them diatoms predominate, approx. 80 different forms of zooplankton. Animal life - walruses, seals, polar bears live mainly in the peripheral parts of A. b.

Lit: Treshnikov A. F. [et al.], Geographical names of the main parts of the relief of the bottom of the Arctic Basin, "Problems of the Arctic and Antarctic", 1967, ╧ 27.

E. G. Nikiforov, V. V. Panov, A. O. Shpaikher.

ARCTIC POOL, Polar Basin, Central Arctic Basin, deep part of the North. Arctic approx., bounded from the south by the edge of the continental shelf of Eurasia and the North. America. Area approx. 5.3 million km 2. A. b. divided by 3 underwater ridges - Gakkel (minimum depth 400 m), Lomonosov (954 m), Mendeleev and uplifts (Alpha and Chukchi) into underwater basins: Nansen (maximum depth 5449 m), Amundsen (4321 m), Makarov (3940 m), Podvodnikov (3285 m), Toll (2780 m), Canadian (3838 m) and North Pole (2288 m). The bottom is covered with a layer of silt with a thickness of 0.5 to 2.5 km. The climate is harsh. Wed temp-pa January from -30 to -34°C, July approx. 0°C. T. o., A. b. all year round it is covered with close-knit drifting ice, mostly multi-year ones ("pak"). Temp-pa of the surface layer of water approx. -1.8°C, salinity is reduced by river runoff and summer ice melting to 30-32°/oo. This layer is underlain by more dense warm Atlantic. waters, to-rye sink to S. from Svalbard and spread throughout A. b. at depths from 150-200 m to 800 m. Their temperature is approx. 1°С, salinity 34.5°/00 and more. In east. parts A. b. at depths of 50 to 100 m, Pacific waters spread, which come from the Bering Sea and can be traced to the ridge. Lomonosov. Their temperature is approx. -1.4 ° C, salinity approx. 33°/oo. Below 800 m A. b. occupied by bottom water with a temperature of approx. -1°C and salinity over 34.5°/oo. The circulation of water and ice is determined by wind and water exchange with the Atlantic. and the Pacific Oceans. In the Canadian region A. b. a stable anticyclonic circulation of ice and surface waters develops. In the rest of A. b. the flow of ice and waters of the Transarctic dominates. currents directed from the Bering Sea to Greenland. Average drift velocities of ice and constant currents A. b. are 2-4 km / day. In the waters of A. b. 70 species of phytoplankton were found, among them diatoms predominate, approx. 80 different forms of zooplankton. Fauna - walruses, seals, polar bears live preim. in peripheral parts And.

Lit .: Treshnikov A. F. [and others]. Geographical names of the main parts of the relief of the bottom of the Arctic Basin, "Problems of the Arctic and Antarctic", 1967, No. 27. E.G. Nikiforov, V.V. Panov.

The main part of the Arctic Ocean is the Arctic Basin. More than half of the basin is occupied by the shelf. According to the names of the marginal Arctic seas, it is divided into the Barents, Kara, Laptev and East Siberian-Chukotka (a significant part adjoins the shores of North America) [ 5 ] .

The Barents Sea shelf in structural and geological terms is precambrian platform with strong case sedimentary breeds Paleozoic And mesozoic. On the outskirts Barents seas bottom is composed of ancient folded complexes of various ages (in Kola peninsulas and northwest of Svalbard - archean-Proterozoic, off the coast New Earth- Hercynian and Caledonian). Saint Anna in the north, the Samoilov Trough in the central part of the Barents Sea, large uplands - the Medvezhinskoye plateau, the Nordkinskaya and Demidov banks, the Central Plateau, the Perseus Upland, the Admiralty Upland. Bottom White seas in the northern and western parts it is folded Baltic Shield, in the eastern Russian platform. The bottom of the Barents Sea is characterized by dense dissection by flooded seas. glacial And river valleys [ 5 ] .

Southern part of the shelf Karsky seas basically a continuation West-Siberian Herzen platform. In the northern part, the shelf crosses the submerged link of the Ural-Novaya Zemlya meganticlinorium, the structures of which continue in the northern Taimyr and archipelago Northern Earth.To the north are the Novaya Zemlya Trench, the Voronin Trench and the Central Karskaya Upland. The Dnokara Sea is crossed by clearly defined continuations of the valleys Obi And Yenisei. Near Novaya Zemlya, Severnaya Zemlya, Taimyr, exaration and accumulative relic glacial landforms are common at the bottom [ 5 ] .

The predominant type of relief on the shelf seas Laptev- marine accumulative plain, along the coasts, and on some banks - abrasive-accumulative plains. The same leveled relief continues at the bottom East-Siberian seas, in some places at the bottom of the sea (about Novosibirsk islands and northwest of bearish islands) the ridge relief is clearly expressed. At the bottom Chukotka seas flooded denudation plains predominate. The southern part of the sea is a deep structural depression filled with loose sediments and Meso-Cenozoic effusives [ 5 ] .

The continental slope of the Arctic Basin is dissected by large wide underwater canyons. The turbidity flow cones form the accumulative shelf - the continental foot. A large fan forms the Mackenzie Submarine Canyon in the southern part Canadian hollows. abyssal part The Arctic Basin is busy middle-oceanic ridge Gakkel and the bed of the ocean. The Gakkel Ridge starts from the Lena Valley, then extends parallel to the Eurasian submarine margin and adjoins the continental slope in the Laptev Sea. Along the rift zone of the ridge are numerous epicenters earthquakes. From the underwater margin of northern Greenland to the continental slope of the Laptev Sea stretches ridge Lomonosov- this is a monolithic mountain structure in the form of a solid shaft. Under the Lomonosov Ridge, it is believed that lies earthly bark continental type. From the underwater margin of the East Siberian Sea north of Wrangel Island to Ellesmere Island in the Canadian Archipelago stretches ridge Mendeleev. It has a blocky structure and is composed of rocks typical of the oceanic crust. There are also two marginal plateaus in the Arctic basin - Ermak north of Svalbard and Chukchi north of the Chukchi Sea. Both of them are formed by the earth's crust of the continental type [ 5 ] .

Between the underwater part of Eurasia and ridge Gakkel lies basin Nansen with a maximum depth of 3975 m. Its bottom is occupied by flat abyssal plains. Between the Haeckel and Lomonosov ridges is located basin Amundsen. The bottom of the basin is a vast flat abyssal plain with a maximum depth of 4485 m. Northern pole located in this basin. Between the Lomonosov and Mendeleev ridges is located basin Makarova with maximum depths of more than 4510 m. The southern, relatively shallow (with a maximum depth of 2793 m) part of the basin is distinguished separately as basin Submariners. The bottom of the Makarov Basin is formed by flat and wavy abyssal plains, the bottom of the Podvodnikov Basin is an inclined accumulative plain. Canadian basin, located kugu from the Mendeleev Ridge and east of the Chukchi Plateau, is the largest basin in terms of area with a maximum depth of 3909 m. Its bottom is mainly a flat abyssal plain. Under all basins, the earth's crust does not have granite layer. The thickness of the crust here is up to 10 km due to a significant increase in the thickness of the sedimentary layer [ 5 ] .

Bottom deposits The Arctic Basin is exclusively of terrigenous origin. Precipitation of fine mechanical composition prevails. In the south of the Barents Sea and in the coastal strip of the White and Kara Seas, sandy deposits. Widespread railway-manganese nodules, but mainly on the shelf of the Barents and Kara seas. The thickness of bottom sediments in the Arctic Ocean reaches 2-4 km, which is explained by the wide distribution of flat abyssal plains. The large thickness of bottom sediments is determined by the high amount of sedimentary material entering the ocean, annually about 2 billion tons, or about 8% of the total amount entering the ocean. World Ocean [ 5 ] .

arctic basin

Polar Basin, Central Arctic Basin, deep-water part of the Arctic Ocean, bounded from the south by the edge of the continental shelf of Eurasia and the North. America. Area approx. 5.3 million km 2. A. b. dissected by 3 underwater ridges - Gakkel (minimum depth 400 m), Lomonosov (954 m), Mendeleev and uplifts (Alpha and Chukchi) on underwater basins: Nansen (the greatest depth is 5449 m), Amundsen (4321 m), Makarova (3940 m), Submariners (3285 m), Toll (2780 l1), Canadian (3838 m) and "North Pole" (2288 m). The bottom is covered with a layer of silt with a thickness of 0.5 to 2.5 km. The climate is harsh. The average temperature in January is from -30 to -34°C, in July approx. 0°C. Thus, A. b. all year round it is covered with close-knit drifting ice, mostly multi-year ones (“pak”). Surface water temperature approx. -1.8°C, salinity is reduced by river runoff and summer ice melting to 30-32‰. This layer is underlain by denser, warm Atlantic waters, which sink northward from Spitsbergen and spread throughout the Atlantic Ocean. at depths from 150-200 m up to 800 m. Their temperature is approx. 1°C, salinity 34.5‰ or more. In the eastern part of A. b. at depths from 50 to 100 m Pacific waters spread, which come from the Bering Sea and can be traced to the Lomonosov Ridge. Their temperature is approx. -1.4 ° C, salinity approx. 33‰. Below 800 m A. b. occupied by bottom water with a temperature of approx. -1°C and salinity over 34.5‰. The circulation of water and ice is determined by wind and water exchange with the Atlantic and Pacific oceans. In the Canadian region A. b. a stable anticyclonic circulation of ice and surface waters develops. In the rest of A. b. the flow of ice and waters of the Transarctic Current, directed from the Bering Sea to Greenland, dominates. Average drift velocities of ice and constant currents A. b. make up 2-4 km/day. In the waters of A. b. 70 species of phytoplankton were found, among them diatoms predominate, approx. 80 different forms of zooplankton. Fauna - walruses, seals, polar bears live mainly in the peripheral parts of A. b.

Lit: Treshnikov A. F. [et al.], Geographical names of the main parts of the relief of the bottom of the Arctic Basin, "Problems of the Arctic and Antarctic", 1967, No. 27.

E. G. Nikiforov, V. V. Panov, A. O. Shpaikher.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

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- (Polar basin) deep part of the North. Arctic approx., bounded from the south by the edge of the shelf of Eurasia and North. America. 5.3 million km². It is dissected by the underwater ridges of Gakkel, Lomonosov and Mendeleev into the basins of Nansen, Amundsen, Makarov, ... ... Big Encyclopedic Dictionary

- (Polar Basin), the deep-water part of the Arctic Ocean, bounded from the south by the edge of the shelf of Eurasia and North America. 5.3 million km2. It is dissected by the underwater ridges of Gakkel, Lomonosov and Mendeleev into the basins of Nansen, Amundsen, ... ... Russian history

Polar Basin, the deep part of the Arctic Ocean, bounded from the south by the edge of the shelf of Eurasia and North America. 5.3 million km2. It is dissected by the Gakkel, Lomonosov and Mendeleev underwater ridges into the Nansen, Amundsen, Makarov basins ... encyclopedic Dictionary

arctic basin- The Arctic Basin, the Polar Basin, the deep part of the Arctic Ocean, bounded from the south by the edge of the continental shelf of Eurasia and North America and the Nansen threshold. The area is about 5.3 million km2, the greatest depth is 5527 m ... Dictionary "Geography of Russia"

See Arctic Basin... Great Soviet Encyclopedia

Arctic shelf: structure, study- The Arctic (from the Greek arktikos - northern), the northern polar region of the Earth, including the outskirts of the continents of Eurasia and North America, almost the entire Arctic Ocean with islands (except for the coastal islands of Norway), as well as adjacent ... ... Encyclopedia of newsmakers

Arctic basin (geology and morphology). St. Petersburg: VNIIOkeangeologiya, 2017. - 291 p.

The geological and geophysical uniqueness of the Arctic Ocean became apparent as early as the 20th century after regional studies were carried out. Nowhere else on Earth is there such a variety of structures of different ages and different characteristics, concentrated in such a small area. Only one well has been drilled in the deep water area of ​​the Arctic Ocean. Until recently, geological and geophysical materials were represented by potential field anomaly maps, bathymetric data, and point seismic soundings. The situation changed radically at the beginning of the 21st century, when the states surrounding the ocean - Russia, Canada, the USA, Denmark and Norway - conducted a number of complex geological and geophysical expeditions in the Arctic basin. The first results of these works have been published. However, a complete seismostratigraphic correlation of the sections of the Arctic Basin has not yet been carried out, there is no recognized classification of geotectonic structures in the region, and the evolutionary history of the formation of these structures has not been worked out. The book offered to readers reflects the progress achieved in solving the problems of the geology of the Arctic Basin.

Geological and geophysical uniqueness of the Arctic Ocean became obvious in the 20th century after reconnaissance studies. Nowhere in the world does one meet such a variety of ages and diverse pattern of structure and all of this focuses on such a small area. Only one hole for seabed mapping has been drilled so far in the deep-water area of ​​the Arctic Ocean. Geological and geophysical data until recently were presented mainly by potential field anomalies, bathymetric data and seismic sounding points. The situation changed dramatically at the beginning of the XXI century, when the coastal states of the Arctic Ocean - Russia, Canada, the United States, Denmark and Norway - conducted complex geological and geophysical expeditions in the central part of the Arctic Ocean. The results of this work are published in the world press. However, to date, there is no correlation of regional seismic-stratigraphic schemes for the Arctic Ocean. There is no universally accepted classification of geotectonic structures of the region and the evolutionary history of their formation has not been developed. Progress in solving the problems of the Arctic Basin geology is presented in this book to readers.

© VNIIOkeangeologiya, 2017

A. L. Piskarev, V. A. Poselov, G. P. Avetisov, V. V. Butsenko, V. Yu. Glebovsky, E. A. Gusev, S. M. Zholondz, V. D. Kaminsky, A. A. Kireev, O. E. Smirnov, Yu. G. Firsov, A. G. Zinchenko, A. D. Pavlenkin, L. G. Poselova, V. A. Savin, A. A. Chernykh, D. V. Elkin.

Ch. editor: corr. RAS V. D. Kaminsky.

Editors: Corr. RANS, Doctor of Geological and Mineralogical Sciences, Professor of St. Petersburg State University A. L. Piskarev and Doctor of Geological and Mineralogical Sciences V.A. Poselov.

Introduction - p.5

List of abbreviations - p.6

1. Modern knowledge of the bottom of the Arctic Basin - p.7

1.1. The relief of the bottom of the Arctic Basin - with. 7

1.2. Morphological elements of the seabed - p. 17

1.3. The study of gravitational and magnetic anomalies - p. 22

1.3.1. Russian Studies - p. 22

1.3.2. Foreign studies - p. 28

1.3.3. International projects - p. 31

1.4. Seismic surveys of reflection waves - p. 36

1.5. Seismic surveys of refraction GSZ - p. 44

1.6. Seismicity of the Arctic - p. 47

1.7. Geological testing and drilling - p. 53

2. Seismic stratigraphy of the sedimentary cover - p.61

2.1. The Amundsen and Nansen basins of the Eurasian basin - with. 61

2.2. The complex of the Central Arctic uplifts of the Amerasian basin (the Lomonosov Ridge, the system of the Mendeleev-Alpha uplifts, the Podvodnikov Basin, the Makarov Basin, the Chukchi Basin and the Chukchi Plateau) and the adjacent shelf of northeastern Eurasia - with. 69

3. Eurasian Basin - p. 87

3.1. Formation and Evolution of the Eurasian Basin According to Traditional Data Interpretation - p. 87

3.2. Gakkel Ridge - c. 94

3.3. Nansen basin - with. 98

3.4. Amundsen Basin - with. 106

3.5. Continental margin in the Laptev Sea - with. 106

3.6. Alternative hypotheses for the evolution of the Eurasian Basin - p. 120

4. Lomonosov Ridge - p.126

4.1. Morphology - p. 129

4.2. Potential fields - p. 132

4.3. Sedimentary cover - with. 133

4.4. Acoustic Foundation - p. 142

4.5. The structure of the earth's crust - p. 142

5. Podvodnikov Basin - p. 148

5.1. Morphology - p. 148

5.2. Potential fields - p. 152

5.3. Acoustic Foundation - p. 154

5.4. Sedimentary cover - with. 157

5.5. The structure of the earth's crust - p. 171

6. Makarov Hollow - p. 180

6.1. Morphology - p. 180

6.2. Potential fields - p. 182

6.3. Sedimentary cover - with. 182

6.4. Earth's crust - p. 185

7. Rise of Mendeleev - p. 188

7.1. Morphology - p. 188

7.2. Potential fields - p. 190

7.3. Sedimentary cover - with. 191

7.4. Acoustic Foundation - p. 209

7.5. The structure of the earth's crust - p. 210

8. Chukchi Plateau and Chukchi Basin - p. 219

8.1. Morphology - p. 219

8.2. Potential fields - p. 221

8.3. Sedimentary deposits - with. 222

8.4. Geological testing. Acoustic Foundation - p. 231

9. Stretching structures on the continental margin of Eurasia - p. 233

10. Canadian basin - p. 238

11. Pliocene-Quaternary sedimentation - p. 250

12. A brief review of the geological and bathymetric data used to justify the boundaries of the legal shelf of the Russian Federation in the Arctic Ocean - p. 269

12.1. The thickness of the earth's crust of the deep-sea region of the Arctic Ocean - p.269

12.2. Analysis of data on the thickness of the sedimentary cover - p. 271

12.3. Bathymetric data - p. 275

Conclusion - p. 276

References - p. 278