The relief of the bottom of the Atlantic Ocean. The main features of the relief of the Atlantic Ocean bed

Let's consider in detail the relief of the bottom of the Atlantic Ocean. This topic is presented in many sources superficially. Therefore, the question is topical for many: "Where can we find the description of the Atlantic Ocean?" After all, it sometimes takes a deep study of this topic. In this article, we tried to maximally reveal this issue.

Starting to describe the relief of the bottom of the Atlantic Ocean, we note that the Mid-Atlantic Ridge is its main orographic element. In terms of area, it is only slightly less than the bed of the ocean (24.6% and 37.6%, respectively). The whole ocean divides this range into two parts. They are approximately equal in area. General information about the Atlantic Ocean, as well as general knowledge of geography will allow you to better understand what is being discussed in this article. In order to better imagine the location of the ocean of interest to us, we suggest that you familiarize yourself with the map.

To the west of the median ridge

Newfoundland ridge is located to the west of the median ridge. The Rio Grande Plateau, the Ceara Rise, the Barracuda Ridge and the Bermuda Plateau, as well as the protrusions of the Mid-Atlantic Ridge and the outskirts of the continents underwater, divide the western half of the ocean bed into the Argentine, Brazilian, Guiana (Guyana), North American, Newfoundland and Labrador Depression . The Norwegian-Greenland basin and the Baffin Sea are usually regarded as parts of another ocean - the Arctic Ocean.

Labrador and Newfoundland hollows

Let us continue the story of what constitutes the relief of the bottom of the Atlantic Ocean. Briefly describe the two hollows - Labrador and Newfoundland (the greatest depth of the last - 5160 meters). They, in essence, constitute a single whole. The main part of them is occupied by a flat abyssal plain. In the submeridional direction, it is crossed by the Abyssal Valley of Hazen. Newfoundland hollow from the south is protected by a ridge with the same name. He, as shown by various seismoacoustic studies, is a giant accumulative form, which is associated with the movement of sedimentary material by deep-water currents.

Basins of North American, Guiana and Ceara

The North American basin is one of the largest basins with which the relief of the bottom of the Atlantic Ocean is marked. A short description of it will continue our story. The greatest depth of the hollow is 7110 meters. The Bermuda plateau is located almost in the center of its northern part. Here, too, the Korner volcanic massif (otherwise known as the Corner Uplift) and the Kelvin Mountains are distinguished. The wavy abyssal plain extends from the Bermuda plateau to the south. On the periphery of the depression are the flat abyssal plains of Nares, Hatteras and Som. The North American basin borders on the south-west with the Blake-Bahamian ridge, as well as with the External Antilles. The latter extends along the trench of Puerto Rico. It separates, together with the blocky Barracuda Range, located on its continuation, the Guiana Basin from the North American one. The inflow of sedimentary terrigenous material provides practically universal development of a flat abyssal plain, called the Demerara Plain, within the Guiana Basin. The Guiana Basin has a maximum depth of 5,109 meters in the northwestern part, characterized mainly by a hilly relief. Small in size, the Cear's rise, complicated by underwater volcanoes, is separated from the Ceará basin. The greatest depth of the latter is 4700 meters. The bottom of this depression is occupied by a flat plain with the same name. It is necessary to note 2 more abyssal valleys. This is Wild, the depth of the embankment reaches 250 meters (connects the Guiana and North American basins), and Pernambuco (connects the Brazilian and Guiana basins).

The Brazilian Basin

The largest basin in the western part of the ocean is the Brazilian. Here the relief of the bottom of the Atlantic Ocean is predominantly hilly. On the plain of Pernambuco, a small section of the basin, it is wavy. A lot of underwater volcanoes are in the Brazilian basin. Some rise above sea level, forming volcanic islands (Martin-Vas, Trinidad, Fernando-di-Noronha). The latitudinal zones of faults are subordinate to the location of the seamounts.

The Brazilian basin from the south is separated by the Rio Grande plateau from the Argentinean plateau. The relief of the plateau is very complicated. Separate seamounts rise above the plateau-like surfaces.

The eastern part has the form of a ridge, narrow, with a flat top. It is stretched in the meridional direction. Between the underwater margin of the continent of South America and the plateau is the Vima - abyssal valley, along which the bottom waters flow from the Argentine to the Brazilian basin. A significant part of the bottom of the Argentinean is covered with a wavy plain. A flat, narrow abyssal plain is located on the western edge of the basin, and in the southern part there is a large accumulative submarine form, the Sapiola Range. Its formation is associated with the inflow of nepheloids and bottom sediments by the Antarctic bottom current. In the Argentine Basin large seamounts are not available, but seismo-acoustic profiles transmit information that several mountains, whose relative altitude reaches 2-2.5 km, is buried under the thickness of precipitation.

The South Antilles outer rampart is an oak rising, located to the south of the Argentine basin. The African-Antarctic basin lies to the south, between Antarctica and the mid-oceanic ridge. The conditional boundary between the Indian and Atlantic oceans is drawn at the level of the 20th century. Etc. If we take into account this boundary, only the western part of the basin with a flat abyssal plain called Uedella is in the Atlantic Ocean. The relief of the abyssal hills is typical for the northern part of the basin.

What is at the depth of the Atlantic Ocean in its eastern part?

The relief of the bottom of the world ocean is quite complex and heterogeneous, consists of many elements. The Atlantic Ocean is no exception. Its lodge in the eastern part is characterized by the presence of the Lateral or Azores-Biscay Range, the Gorringe Massif, the uplift of the Cape Verde Islands and the Canary Islands, the Sierra Leone Plateau, the Whale and the Guinea Upland Ridge. They divide the entire eastern part of the ocean into the West European (the greatest depth is 5023 meters), the Canary (6549 meters), the Iberian (5815 meters), the Sierra Leone (6,040 meters), the Cape Verde (7282 meters), the Angola (6,050 meters), the Guinean (5215 meters) and the Cape (5457 meters) basin. Between Rockall, the underwater elevation, and the Iceland-Farrer threshold is located the West European hollow.

Western European hollow

The bottom of the basin is mainly an abyssal hilly plain, only in the Bay of Biscay, and also to the north-west of it stretches the Biscay flat plain. From the north to the south, the bottom is cut by a large abyssal Mori valley, the length of which is about 3500 km. It is similar morphologically with the valley of Hazen. The valley is accompanied on a large extent by accumulative shafts, reaching a height of 50 meters. Two huge accumulative forms stand out in the northern part of this basin. These are the "sedimentary ridges" of Feni and Gardar. Their formation is associated with increased receipt from the Iceland-Faroe threshold of sedimentary material. Iberian basin, small in size, is occupied in the central part by a flat abyssal plain. With the Biscay plain it joins the Tet gorge.

To the south of the Iberian Basin

The relief of the bottom of the Atlantic Ocean to the south of the Iberian basin is very crossed. Its features are determined by the presence here of the Gorindzh Range, the volcanic block, as well as the seamount of the same name, the rise of Madeira and a group of other seamounts. The main features of the relief of the Atlantic Ocean bed in this area also include the presence of many underwater volcanoes. According to the structure of the surface, the bottom of the Zelenomyssky Basin, as well as the extensive Canary (the greatest depth is 6549 meters) can be divided into 3 submeridional zones: the eastern, oceanic crust within which is covered by a completely inclined plain of the foot of the continent; The middle abyssal plain, flat and narrow; Hilly western. Elements of the underwater margin of the continent of Africa are also the volcanic uplifts of the Canary Islands (4 active volcanoes among them) and the islands of the Cape Verde with an active volcano. All this and more are hidden in the depths of the Atlantic Ocean.

Very high velocities (7-7.3 km / s) of seismic waves are characterized by the rise of Sierra Leone. This is due to the introduction of ultrabasic rocks into the earth's crust, as well as to strong metamorphism of various crustal rocks. The bottom of such hollows, as the Guinean and Sierra Leone, is occupied by flat plains, which are surrounded by abyssal hills. The greatest depths of these basins are 5212 and 6040 meters, respectively.

Cameroon fault zone

The wide Guinean Uplift stretched to the northeast of the lava plateau, extensive and located in the eastern part of the Mid-Atlantic ridge, near St. Helena. The Cameroonian fault zone is the most characteristic element of this uplift. It is associated with the volcanic structures of the Shirshov submerged mountain, as well as the islands of Palanga, Principe, Sao Tome and Macias Nguema Biyogo. The fault zone further extended within the continent of Africa. Cameroon, the active volcano, and several Central Sahara, among which there are also active, are confined to it.

Angolan hollow

The bottom lying to the southeast and south of the Guinean uplift of the Angolan basin is also largely covered by inclined plumes of the foot of the continent, including the vast cone of the Congo, the underwater canyon. The group of seamounts is located in the southernmost corner of the Angolan basin. These mountains have a common ground. The most significant of them is the city of Wurst (its relative height is about 4 km).

Whale Ridge

The whale ridge is a mountain block structure. It consists of 3 large blocks, which are separated by saddles. The whale ridge is characterized by a flattened vertex surface and steep slopes. The alignment of the vertex surface is associated in a large (and possibly main) degree with the accumulation of a series of calcareous deposits.

Cape of the Cape

Located to the south of the Whale Ridge, the Kap basin is distinguished by the fact that the relief of the abyssal hills is mainly developed here. In addition, the depths of the Atlantic Ocean conceal a multitude of volcanic mountains. They are concentrated mainly in the southern part of this basin. The group of these mountains separates the Cape basin from the Agulhas basin. Agulhas is considered mainly as part of the Indian Ocean bed . It is similar morphologically to the Cape basin.

Now you know what the relief of the bottom of the Atlantic Ocean is at the moment. It is gradually changing, although significant changes are very slow. After all, the continents drift at a rate of only about 1-2 cm per year. Other processes that affect it also proceed very slowly. Therefore, the main features of the relief of the bottom of the Atlantic Ocean remain unchanged.

What explains the features of the Atlantic Ocean relief?

Why is the bottom relief exactly what it is? Let's figure it out. Features that have a relief of the bottom of the ocean, scientists today can explain specific reasons. In particular, the Atlantic Ocean is believed to have been formed as a result of the discovery of the rift in the axial zone of the Mediterranean-Atlantic ridge. All the features of the structure and topography of the bottom of this ocean are explained by the fact that the four main plates (Antarctic, African, Eurasian and American) are mutually moving.

The history of the study of the Atlantic Ocean began in ancient times. Meanwhile, its depths are not yet fully understood. It is possible that the history of the study of the Atlantic Ocean will be continued with new interesting discoveries.