The Pacific Ocean is the largest of the oceans. Its area is 178.7 million km 2. The ocean surpasses all the continents combined in area and has a rounded configuration: it is noticeably elongated from the northwest to the southeast, therefore, air and water masses are most developed here in the vast northwestern and southeastern waters. The length of the ocean from north to south is about 16 thousand km, from west to east - more than 19 thousand km. It reaches its maximum width in equatorial-tropical latitudes, so it is the warmest of the oceans. The volume of water is 710.4 million km 3 (53% of the water volume of the World Ocean). The average depth of the ocean is 3980 m, the maximum is 11 022 m (Mariana Trench).
The ocean washes the shores of almost all continents except Africa. It goes to Antarctica on a wide front, and its cooling effect spreads through the waters and far to the north. On the contrary, Tikhy is protected from cold air masses by significant isolation (the close location of Chukotka and Alaska with a narrow strait between them). In this regard, the northern half of the ocean is warmer than the southern. The Pacific Ocean basin is connected to all other oceans. The boundaries between them are rather arbitrary. The most justified is the border with the Arctic Ocean: it runs along the underwater rapids of the narrow (86 km) Bering Strait somewhat south of the Arctic Circle. The border with the Atlantic Ocean runs along the wide Drake Passage (along the line of Cape Horn in the archipelago - Cape Sternek on the Antarctic Peninsula). The border with the Indian Ocean is conditional.
Usually it is carried out as follows: the Malay archipelago is referred to the Pacific Ocean, and between Australia and Antarctica, the oceans are delimited along the meridian of Cape South (Tasmania Island, 147 ° E). The official border with the Southern Ocean ranges from 36 ° S. NS. off the coast of South America to 48 ° S. NS. (at 175 ° W). The outlines of the coastline are quite simple on the eastern edge of the ocean and very complex on the western one, where the ocean occupies a complex of marginal and inter-island seas, island arcs and deep-sea trenches. This is a vast area of the largest horizontal and vertical dissection of the earth's crust on Earth. The marginal type includes seas off the coast of Eurasia and Australia. Most of the inter-island seas are located in the area of the Malay Archipelago. They are often grouped together under the general name Australian-Asian. The seas are separated from the open ocean by numerous groups of islands and peninsulas. Island arcs are usually accompanied by deep-sea trenches, the number and depth of which the Pacific Ocean is unmatched. The shores of North and South America are weakly indented, there are no marginal seas and such large clusters of islands. Deep-sea trenches are located directly off the coasts of the continents. Off the coast of Antarctica in the Pacific sector there are three large marginal seas: Ross, Amundsen and Bellingshausen.
The outskirts of the ocean, together with the adjacent parts of the continents, are part of the Pacific mobile belt ("ring of fire"), which is characterized by powerful manifestations of modern volcanism and seismicity.
The islands of the central and southwestern parts of the ocean are united under the general name Oceania.
The enormous size of the Pacific Ocean is associated with its peculiar records: it is the deepest, warmest on the surface, the highest wind waves, the most destructive tropical hurricanes and tsunamis, etc. are formed here. The position of the ocean in all latitudes determines the exceptional diversity of its natural conditions and resources ...
Occupying about 1/3 of the surface of our planet and almost 1/2 of the area, the Pacific Ocean is not only a unique geophysical object of the Earth, but also largest region multilateral economic activities and the diverse interests of mankind. Since ancient times, the inhabitants of the Pacific shores and islands have explored the biological resources of coastal waters and made short-range voyages. Over time, other resources began to be involved in the economy, and their use became widespread. Today, the Pacific Ocean plays a very important role in the life of many countries and peoples, which is largely determined by its natural conditions, economic and political factors.
Features of the economic and geographical location of the Pacific Ocean
In the north, vast expanses of the Pacific Ocean through the Bering Strait are connected to the Arctic Ocean.
The border between them runs along a conventional line: Cape Unikyn (Chukotka Peninsula) - Shishmareva Bay (Seward Peninsula). In the west, the Pacific Ocean is bounded by the mainland of Asia, in the southwest - by the shores of the islands of Sumatra, Java, Timor, then by the eastern coast of Australia and a conventional line crossing the Bass Strait and then along the coast of the island of Tasmania, and further south along the ridge of underwater uplifts to Cape Alden on Wilkes Land c. The eastern boundaries of the ocean are the shores of North and South America, and to the south is a conventional line from the island of Tierra del Fuego to the Antarctic Peninsula on the continent of the same name. In the extreme South, the waters of the Pacific Ocean wash over Antarctica. Within these limits, it occupies an area of 179.7 million km 2, including the marginal seas.
The ocean has a spherical shape, especially pronounced in the northern and eastern parts. Its greatest length in latitude (about 10,500 miles) is noted along the parallel of 10 ° N, and its greatest length (about 8500 miles) falls on the 170 ° W meridian. Such a great distance between the northern and southern, western and eastern shores is an essential natural feature of this ocean.
The coastline of the ocean is heavily indented in the west; in the east, the coasts are mountainous and weakly dissected. In the north, west and south of the ocean are large seas: Beringovo, Okhotsk, Japanese, Yellow, East China, South China, Sulawesi, Javanskoe, Ross, Amundsen, Bellingshausen, etc.
The bottom relief of the Pacific Ocean is complex and uneven. In most of the transitional zone, the shelves do not have significant development. For example, off the American coast, the shelf width does not exceed several tens of kilometers, but in the Bering, East China, South China Seas it reaches 700-800 km. In general, the shelves occupy about 17% of the entire transition zone. The continental slopes are steep, often stepped, dissected by underwater canyons. The ocean floor takes up a huge area. It is divided into large basins by a system of large uplifts, ridges and individual mountains, wide and relatively low swells: North-East, North-West, East Mariana, West Carolina, Central, South, etc. The most significant East Pacific uplift is included in the world system of mid-ocean ridges. In addition to it, large ridges are widespread in the ocean: Hawaiian, Imperial Mountains, Karolinsky, Shatsky, etc. to New Zealand.
The vast expanses of the Pacific Ocean cover all natural belts from the northern subpolar to the southern polar, which is the reason for the diversity of its climatic conditions. Moreover, the most significant part of the ocean space, located between 40 ° N. NS. and 42 ° S, is located within the equatorial, tropical and subtropical zones. The southern marginal part of the ocean is climatically more severe than the northern one. Due to the cooling influence of the Asian continent and the predominance of the west-east transport, typhoons are characteristic of the temperate and subtropical latitudes of the western part of the ocean, especially frequent in June-September. The northwestern part of the ocean is characterized by monsoons.
The exceptional dimensions, peculiar outlines, large-scale atmospheric processes largely determine the peculiarities of the hydrological conditions of the Pacific Ocean. Since a fairly significant part of its area is located in equatorial and tropical latitudes, and the connection with the Arctic Ocean is very limited, since the water on the surface is higher than in other oceans and is 19'37 °. The predominance of precipitation over evaporation and a large river runoff determine a lower salinity of surface waters than in other oceans, the average value of which is 34.58% o.
The temperature and salinity on the surface change both in the water area and in the seasons. The most noticeable seasonal changes in temperature in the western part of the ocean. Seasonal fluctuations in salinity are generally small. Vertical changes in temperature and salinity are observed mainly in the upper, 200-400-meter layer. At great depths, they are insignificant.
The general circulation in the ocean is made up of horizontal and vertical movements of water, which, to one degree or another, can be traced from the surface to the bottom. Under the influence of large-scale atmospheric circulation over the ocean, surface currents form anticyclonic gyres in subtropical and tropical latitudes and cyclonic gyres in northern temperate and southern high latitudes. The ring-shaped movement of surface waters in the northern part of the ocean is formed by the North trade wind, Kuroshio, North Pacific warm currents, Californian, Kuril cold and Alaskan warm currents. The system of circular currents of the southern regions of the ocean includes warm South Passat, East Australian, zonal South Pacific and cold Peruvian. The rings of currents of the northern and southern hemispheres throughout the year separate the Inter-trade Current, passing north of the equator, in a strip between 2-4 ° and 8-12 ° N. The speeds of surface currents are different in different regions of the ocean and change with the seasons. Vertical water movements of different mechanism and intensity are developed throughout the ocean. Density mixing occurs in the surface horizons, which is especially significant in areas of ice formation. In the zones of convergence of surface currents, surface waters sink, and the underlying waters rise. The interaction of surface currents and vertical water movements is one of the critical factors formation of the structure of waters and water masses of the Pacific Ocean.
In addition to these main natural features, the economic development of the ocean is strongly influenced by social and economic conditions characterized by the EGP of the Pacific Ocean. In relation to the oceanic land areas, the EGP has its own distinctive features... The Pacific Ocean and its seas are washed by the coasts of three continents, on which there are more than 30 coastal states with the general population about 2 billion people, i.e. about half of humanity lives here.
Countries go to the Pacific Ocean - Russia, China, Vietnam, USA, Canada, Japan, Australia, Colombia, Ecuador, Peru, etc., Each of the three main groups of the Pacific Ocean states includes countries and their regions with a more or less high level of economic development ... This affects the nature and possibilities of using the ocean.
The length of the Pacific coast of Russia is more than three times the length of the coastline of our Atlantic seas. In addition, unlike the western ones, the Far Eastern seashores form a continuous front, which facilitates economic maneuvering in its individual areas. However, the Pacific Ocean is far from the main economic centers and densely populated areas of the country. This remoteness seems to be decreasing as a result of the development of industry and transport in the eastern regions, but nevertheless it significantly affects the nature of our relations with this ocean.
Almost all the mainland states and many island states, excluding Japan, adjacent to the Pacific Ocean basin, have large reserves of various natural resources that are intensively developed. Consequently, the sources of raw materials are located relatively evenly along the periphery of the Pacific Ocean, and the centers of its processing and consumption are located mainly in the northern part of the ocean: in the USA, Japan, Canada and, to a lesser extent, in Australia. The uniformity of distribution of natural resources along the coast of the ocean and the confinement of their consumption to certain centers is a characteristic feature of the EGP of the Pacific Ocean.
Continents and partly islands in vast areas separate the Pacific Ocean from other oceans by natural boundaries. Only to the south of Australia and New Zealand are the Pacific waters connected by a wide front with the waters of the Indian Ocean, and through the Strait of Magellan and Drake Passage - with the waters of the Atlantic. In the north, the Pacific Ocean is connected to the Arctic by the Bering Strait. In general, the Pacific Ocean, excluding its Antarctic regions, is connected to other oceans in a relatively small part. The routes, its communications with the Indian Ocean pass through the Australo-Asian seas and their straits, and with the Atlantic - along the Panama Canal and the Strait of Magellan. The narrowness of the straits of the seas of Southeast Asia, the limited carrying capacity of the Panama Canal, the remoteness of vast expanses of Antarctic waters from the major world centers reduce the transport capabilities of the Pacific Ocean. This is an important feature of its EGP in relation to the world's sea routes.
The history of the formation and development of the basin
The pre-Mesozoic stage of the development of the World Ocean is largely based on assumptions, and many questions of its evolution remain unclear. With regard to the Pacific Ocean, there are many indirect data indicating that the Paleo-Pacific Ocean has existed since the middle of the Precambrian. He washed the only continent of the Earth - Pangea-1. It is believed that the presence of ophiolite associations of rocks in folded systems found throughout the continental periphery of the ocean and dating back to the Late Cambrian is considered to be direct evidence of the antiquity of the Pacific Ocean, despite the youth of its modern crust (160-180 Ma). The history of ocean development in the Mesozoic and Cenozoic times has been more or less reliably reconstructed.
The Mesozoic stage, apparently, played a large role in the evolution of the Pacific Ocean. The main event of the stage is the collapse of Pangea-II. In the Late Jurassic (160-140 million years ago), the opening of the young Indian and Atlantic oceans took place. The expansion of their bed (spreading) was compensated by the reduction in the area of the Pacific Ocean and the gradual closure of the Tethys. The ancient oceanic crust of the Pacific Ocean plunged into the mantle (subduction) in the Zavaritsky-Beniof zones, which bordered the ocean, as at present, in an almost continuous strip. At this stage in the development of the Pacific Ocean, the restructuring of its ancient mid-oceanic ridges took place.
The formation of folded structures in northeastern Asia and Alaska in the Late Mesozoic separated the Pacific Ocean from the Arctic Ocean. In the east, the development of the Andean belt absorbed the island arcs.
Cenozoic stage
The Pacific Ocean continued to shrink due to the advancing continents on it. As a result of the continuous movement of America to the west and the absorption of the ocean floor, the system of its middle ridges was significantly displaced to the east and southeast and even partially submerged under the continent of North America in the Gulf of California region. The marginal seas of the northwestern water area were also formed, and the island arcs of this part of the ocean acquired a modern look. In the north, during the formation of the Aleut island arc, the Bering Sea was cut off, the Bering Strait opened, and the cold waters of the Arctic Ocean began to flow into the Pacific Ocean. The basins of the Ross, Bellingshausen and Amundsen Seas formed off the coast of Antarctica. There was a major fragmentation of the land that connected Asia and Australia, with the formation of numerous islands and seas of the Malay Archipelago. The marginal seas and islands of the transition zone to the east of Australia have acquired a modern look. 40-30 million years ago, an isthmus was formed between the Americas, and the connection between the Pacific Ocean and the Atlantic Ocean in the Caribbean region was finally interrupted.
Over the past 1-2 million years, the size of the Pacific Ocean has decreased very slightly.
The main features of the bottom relief
As in other oceans, all the main planetary morphostructural zones are clearly distinguished in the Pacific: the underwater margins of the continents, transition zones, the ocean floor and mid-ocean ridges. But the general plan of the bottom relief, the ratio of the areas and the location of the indicated zones, despite a certain similarity with other parts of the World Ocean, are distinguished by great originality.
The underwater margins of the continents occupy about 10% of the Pacific Ocean, which is much smaller in comparison with other oceans. The continental shelf (shelf) accounts for 5.4%.
The shelf, like the entire submarine margin of the continents, reaches its greatest development in the western (Asian-Australian) littoral sector, in the marginal seas - the Bering, Okhotsk, Yellow, East China, South China, the seas of the Malay archipelago, as well as to the north and east from Australia. The shelf is wide in the northern part of the Bering Sea, where there are flooded river valleys and traces of relict glacial activity. A submerged shelf is developed in the Sea of Okhotsk (1000-1500 m deep).
The continental slope is also wide, with signs of fault-block dissection, cut by large underwater canyons. The continental foot is a narrow plume of accumulation of products of removal of turbidity flows and landslide masses.
To the north of Australia is a vast continental shelf with ubiquitous coral reefs. In the western part of the Coral Sea there is a unique structure of the Earth - the Great Barrier Reef. This is a discontinuous strip of coral reefs and islands, shallow bays and straits, stretching in the meridional direction for almost 2500 km, in the northern part it is about 2 km wide, in the southern part up to 150 km. The total area is more than 200 thousand km 2. At the base of the reef lies a thick stratum (up to 1000-1200 m) of dead coral limestone, accumulated in the conditions of slow subsidence of the earth's crust in this area. To the west, the Great Barrier Reef descends gently and is separated from the mainland by an extensive shallow lagoon - a strait up to 200 km wide and no more than 50 m deep. In the east, the reef breaks off with an almost vertical wall to the continental slope.
The submarine margin of New Zealand is a peculiar structure. The New Zealand plateau consists of two flat-topped uplifts: Campbell and Chatham, separated by a depression. The underwater plateau is 10 times the area of the islands themselves. This is a huge block of the earth's crust of the continental type, with an area of about 4 million km 2, not associated with any of the nearest Continents. Almost from all sides the plateau is bounded by the continental slope, which turns into the foot. This peculiar structure, called the New Zealand microcontinent, has existed at least since the Paleozoic.
The submarine margin of North America is represented by a narrow strip of flattened shelf. The continental slope is heavily indented by numerous underwater canyons.
The area of the underwater outskirts located to the west of California and called the California Borderland is peculiar. The bottom relief here is large-block, characterized by a combination of underwater heights - horsts and depressions - grabens, the depths of which reach 2500 m. The relief character of the borderland is similar to the relief of the adjacent land area. It is believed that this is a part of the continental shelf, which is heavily fragmented and submerged to different depths.
The submarine margin of Central and South America has a very narrow shelf, only a few kilometers wide. Over a long distance, the continental side of deep-water trenches plays the role of a continental slope. The continental foot is practically not expressed.
A significant part of the continental shelf of Antarctica is covered by ice shelves. The continental slope here is distinguished by its great width and dissection by submarine canyons. The transition to the ocean floor is characterized by weak manifestations of seismicity and modern volcanism.
Transition zones
These morphostructures within the Pacific Ocean occupy 13.5% of its area. They are extremely diverse in their structure and most fully expressed in comparison with other oceans. This is a natural combination of marginal seas basins, island arcs and deep-sea trenches.
In the Western Pacific (Asian-Australian) sector, a number of transition areas are usually distinguished, replacing one another mainly in the submeridional direction. Each of them is different in its structure, and perhaps they are at different stages of development. The Indonesian-Philippine region is complexly built, including the South China Sea, seas and island arcs of the Malay Archipelago and deep-sea trenches, which are located here in several rows. To the northeast and east of New Guinea and Australia is also the complex Melanesian region, in which island arcs, hollows and troughs are arranged in several echelons. To the north of the Solomon Islands there is a narrow depression with depths of up to 4000 m, on the eastern extension of which the Vityaz Trench (6150 m) is located. OK. Leontiev singled out this area into a special type of transition zone - Vityazevo. A feature of this area is the presence of a deep-water trench, but the absence of an island arc along it.
In the transition zone of the American sector, there are no marginal seas, no island arcs, and there are only deep-water trenches Central American (6662 m), Peruvian (6601 m) and Chilean (8180 m). Island arcs in this zone are replaced by young folded mountains of Central and South America, where active volcanism is concentrated. In the trenches, there is a very high density of earthquake epicenters with a magnitude of up to 7-9 points.
The transitional zones of the Pacific Ocean are the regions of the most significant vertical dissection of the earth's crust on Earth: the elevation of the Mariana Islands over the bottom of the trench of the same name is 11,500 m, and of the South American Andes over the Peruvian-Chilean trench - 14,750 m.
Mid-ocean ridges (uplifts). They occupy 11% of the Pacific Ocean and are represented by the South Pacific and East Pacific uplifts. The mid-oceanic ridges of the Pacific Ocean differ in structure and location from similar structures in the Atlantic and Indian Oceans. They do not occupy the middle position and are significantly shifted to the east and southeast. This asymmetry of the present-day spreading axis in the Pacific Ocean is often explained by the fact that it is in the stage of a gradually closing oceanic trench, when the rift axis shifts to one of its edges.
The structure of the mid-oceanic uplifts of the Pacific Ocean also has its own characteristics. These structures are characterized by a vaulted profile, considerable width (up to 2000 km), a discontinuous strip of axial rift valleys with a wide participation in the formation of the relief of transverse fault zones. The East Pacific Rise is dissected by subparallel transform faults into separate blocks shifted with respect to each other. The entire uplift consists of a series of gently sloping domes, with the spreading center being confined to the middle part of the dome, approximately by equal distances from the faults bordering it from the north and south. Each of these domes is also dissected by echelon-like short faults. Large transverse faults cut the East Pacific Rise every 200-300 km. The length of many transform faults exceeds 1500-2000 km. Often they not only cross the flank zones of the uplift, but also go far out on the ocean floor. Among the largest structures of this type are Mendocino, Murray, Clarion, Clipperton, Galapagos, Easter, Eltanin, etc. The high density of the earth's crust under the crest, high values of heat flow, seismicity, volcanism and a number of others are manifested very clearly, despite the fact that the rift the system of the axial zone of the mid-oceanic uplifts of the Pacific Ocean is less pronounced than in the Mid-Atlantic and other ridges of this type.
North of the equator, the East Pacific Rise narrows. The rift zone is clearly defined here. In the California area, this structure invades the North American mainland. This is associated with the breakaway of the California Peninsula, the formation of the large active San Andreas fault and a number of other faults and depressions within the Cordillera. The formation of the California borderland is probably connected with this.
The absolute marks of the bottom topography in the axial part of the East Pacific Rise are everywhere around 2500-3000 m, but at some elevations they decrease to 1000-1500 m.The foot of the slopes is clearly traced along the 4000 m isobath, and the bottom depths in the framing basins reach 5000-6000 m On the highest elevation sites are about. Easter and Galapagos Islands. Thus, the amplitude of uplift above the surrounding basins is, on the whole, very high.
The South Pacific Rise, separated from the East Pacific by the Eltanin Fault, is very similar in structure to it. The length of the Eastern uplift is 7600 km, the South one - 4100 km.
Ocean bed
It occupies 65.5% of the total area of the Pacific Ocean. Mid-oceanic uplifts divide it into two parts, differing not only in their size, but also in the features of the bottom topography. The eastern (more precisely, southeastern) part, which occupies 1/5 of the ocean floor, is shallower and less complex in comparison with the vast western part.
A large portion of the eastern sector is occupied by morphostructures that are directly related to the East Pacific Rise. Here are its lateral branches - the Galapagos and Chilean uplifts. Large blocky ridges Tehuantepec, Kokosovy, Carnegie, Noska, Sala-i-Gomez are confined to the zones of transform faults that cross the East Pacific Rise. Underwater ridges divide eastern part ocean floor on a number of basins: Guatemalan (4199 m), Panama (4233 m), Peruvian (5660 m), Chilean (5021 m). The Bellingshausen Basin (6063 m) is located in the extreme southeastern part of the ocean.
The vast western part of the Pacific Ocean floor is characterized by significant structural complexity and a variety of landforms. Almost all morphological types of underwater bed uplifts are located here: arched ramparts, block mountains, volcanic ridges, marginal uplifts, individual mountains (guyots).
The arched bottom uplifts are wide (several hundred kilometers) linearly oriented swells of the basalt crust with an excess of 1.5 to 4 km over the adjacent basins. Each of them is like a giant rampart, dissected by faults into a number of blocks. Usually, entire volcanic ridges are confined to the central vaulted, and sometimes to the flank zones of these uplifts. So, the largest Hawaiian swell is complicated by a volcanic ridge, some of the volcanoes are active. The surface tops of the ridge form the Hawaiian Islands. The biggest one is about. Hawaii is a volcanic massif of several merged shield basalt volcanoes. The largest of them - Mauna Kea (4210 m) makes Hawaii the highest of the oceanic islands in the World Ocean. Towards the northwest, the size and height of the islands in the archipelago decrease. Most of the islands are volcanic, 1/3 are coral.
The most significant swells and ridges of the western and central parts of the Pacific Ocean have a common pattern: they form a system of arcuate, subparallel uplifts.
The northernmost arc is formed by the Hawaiian Ridge. To the south, there is the next one, the largest in length (about 11 thousand km), starting with the Cartographers Mountains, which then pass into the Markus-Necker (Midpasific) mountains, giving way to the underwater ridge of the Line Islands and then passing into the base of the Tuamotu Islands. The underwater continuation of this upland can be traced further to the east up to the East Pacific uplift, where at the point of their intersection is about. Easter. The third mountain arc begins at the northern part of the Mariana Trench with the Magellan Mountains, which pass into the underwater base of the Marshall Islands, Gilbert Islands, Tuvalu, Samoa. Probably, the ridge of the southern Cook and Tubu Islands continues this mountain system. The fourth arc begins with the uplift of the North Carolina Islands, passing into the Kapingamarangi underwater rampart. The last (southernmost) arc also consists of two links - the South Carolina Islands and the Auriapik underwater swell. Most of the islands mentioned, which mark arched underwater shafts on the ocean surface, are coral, with the exception of the volcanic islands of the eastern part of the Hawaiian Ridge, Samoa Islands, etc. There is an idea (G. Menard, 1966) that many underwater uplifts in the central part of the Pacific Ocean - relics of the mid-oceanic ridge that existed here in the Cretaceous (called the Darwin Rise), which in the Paleogene underwent severe tectonic destruction. This uplift extended from the Cartographers Mountains to the Tuamotu Islands.
Blocky ridges are often accompanied by faults not associated with mid-oceanic uplifts. In the northern part of the ocean, they are confined to the submeridional fault zones south of the Aleutian Trench, along which the Northwest Ridge (Imperial) is located. Blocky ridges accompany a large fault zone in the Philippine Sea Basin. Fault systems and blocky ridges have been identified in many depressions in the Pacific Ocean.
Various uplifts of the Pacific Ocean bed together with mid-oceanic ridges form a kind of orographic frame of the bottom and separate the oceanic basins from each other.
The largest basins in the west-central part of the ocean are: North-West (6671 m), North-East (7168 m), Philippine (7759 m), East Mariana (6440 m), Central (6478 m), West Carolina ( 5798 m), East Carolina (6920 m), Melanesian (5340 m), South Fijian (5545 m), South (6600 m), etc. The bottoms of the Pacific Ocean basins differ low power bottom sediments, in connection with which flat abyssal plains are very sparsely distributed (the Bellingshausen Basin due to the abundant supply of terrigenous sedimentary material carried from the Antarctic continent by icebergs, the Northeastern Basin and a number of other areas). Carrying out of material to other basins is "intercepted" by deep-water trenches, and therefore the relief of hilly abyssal plains prevails in them.
The Pacific Ocean floor is characterized by separately located guyots - seamounts with flat peaks, at depths of 2000-2500 m. Coral structures and atolls were formed on many of them. Guyots, as well as the large thickness of dead coral limestones on the atolls, testify to significant subsidence of the earth's crust within the Pacific floor during the Cenozoic.
The Pacific Ocean is the only one whose bed is almost entirely within the limits of oceanic lithospheric plates (Pacific and small - Nazca, Cocos) with a surface at a depth of 5500 m on average.
Bottom sediments
The bottom sediments of the Pacific Ocean are extremely diverse. Terrigenous sediments are developed in the marginal parts of the ocean on the continental shelf and slope, in the marginal seas and deep-water trenches, and in some places on the ocean floor. They cover more than 10% of the Pacific Ocean floor area. Terrigenous iceberg deposits form a strip near Antarctica with a width of 200 to 1000 km, reaching 60 ° S. NS.
Among biogenic sediments, the largest areas in the Pacific Ocean, as in all others, are occupied by carbonate (about 38%), mainly foraminiferal sediments.
Foraminiferal oozes are distributed mainly south of the equator up to 60 ° S. NS. In the Northern Hemisphere, their development is limited to the summit surfaces of ridges and other uplifts, where bottom foraminifera prevail in the composition of these silts. Pteropod deposits are common in the Coral Sea. Coral sediments are located on the shelves and continental slopes within the equatorial-tropical belt of the southwestern part of the ocean and occupy less than 1% of the ocean floor area. Shellfish, consisting mainly of bivalve shells and their fragments, are found on all shelves, except for the Antarctic. Biogenic siliceous sediments cover more than 10% of the Pacific Ocean floor area, and together with siliceous-carbonate sediments, about 17%. They form three main belts of siliceous accumulation: the northern and southern siliceous diatom oozes (at high latitudes) and the equatorial belt of siliceous radiolarian sediments. In areas of modern and Quaternary volcanism, pyroclastic volcanic sediments are observed. Important distinctive feature bottom sediments of the Pacific Ocean - a wide distribution of deep-water red clays (more than 35% of the bottom area), which is explained by the great depths of the ocean: red clays are developed only at depths of more than 4500-5000 m.
Mineral resources of the bottom
The Pacific Ocean contains the most significant areas of distribution of ferromanganese nodules - more than 16 million km 2. In some areas, the content of nodules reaches 79 kg per 1 m 2 (on average, 7.3-7.8 kg / m 2). Experts predict a bright future for these ores, claiming that their mass production can be 5-10 times cheaper than obtaining such ores on land.
The total reserves of ferromanganese nodules at the bottom of the Pacific Ocean are estimated at 17 thousand billion tons. Pilot industrial development of nodules is carried out by the United States and Japan.
Other minerals in the form of nodules are phosphorite and barite.
Commercial reserves of phosphorites were found near the California coast, in the shelf parts of the Japanese island arc, off the coast of Peru and Chile, near New Zealand, in California. Phosphorites are mined from depths of 80-350 m. The reserves of this raw material are large in the open part of the Pacific Ocean within the limits of underwater uplifts. Barite nodules are found in the Sea of Japan.
Placer deposits of metal-bearing minerals are currently of great importance: rutile (titanium ore), zircon (zirconium ore), monazite (thorium ore), etc.
Australia takes the leading place in their production, along its eastern coast the placers stretch for 1.5 thousand km. Coastal-marine placers of cassiterite concentrate (tin ore) are located on the Pacific coast of mainland and island Southeast Asia. Placers of cassiterite are significant off the coast of Australia.
Titanium-magnetite and magnetite placers are being developed at about. Honshu in Japan, in Indonesia, in the Philippines, in the USA (near Alaska), in Russia (near Iturup Island). Gold sands are known off the western coast of North America (Alaska, California) and South America (Chile). Platinum sands are mined off the coast of Alaska.
In the eastern part of the Pacific Ocean near the Galapagos Islands in the Gulf of California and in other places in rift zones, ore-forming fluids ("black smokers") have been identified - outlets of hot (up to 300-400 ° C) juvenile waters with a high content of various compounds. This is where the formation of deposits of polymetallic ores takes place.
Among the nonmetallic raw materials located in the shelf zone, glauconite, pyrite, dolomite, building materials - gravel, sand, clays, shell limestone, etc. are of great importance. coal.
Oil and gas shows have been found in many areas of the shelf zone in both the western and eastern parts of the Pacific Ocean. Oil and gas production is carried out by the USA, Japan, Indonesia, Peru, Chile, Brunei, Papua, Australia, New Zealand, Russia (in the area of Sakhalin Island). The development of oil and gas resources of the Chinese shelf is promising. The Bering, Okhotsk and Japanese seas are considered promising for Russia.
In some areas of the Pacific Ocean shelf, coal-bearing strata occur. Extraction of coal from the depths of the seabed in Japan accounts for 40% of the total. On a smaller scale, coal is mined by sea in Australia, New Zealand, Chile and some other countries.
Magellan discovered the Pacific Ocean in the fall of 1520 and called the ocean the Pacific Ocean, "because, - as one of the participants reports, during the transition from Tierra del Fuego to the Philippine Islands, more than three months - we have never experienced the slightest storm." In terms of the number (about 10 thousand) and the total area of the islands (about 3.6 million km²), the Pacific Ocean ranks first among the oceans. In the northern part - Aleutian; in the west - Kuril, Sakhalin, Japanese, Philippine, Big and Small Sunda, New Guinea, New Zealand, Tasmania; in the central and southern parts there are numerous small islands. The bottom relief is varied. In the east - the East Pacific uplift, in the central part there are many depressions (North-East, North-West, Central, East, South, etc.), deep-water trenches: in the north - Aleutian, Kuril-Kamchatsky, Izu-Boninsky; in the west - the Mariana (with the maximum depth of the World Ocean - 11,022 m), Philippine and others; in the east - Central American, Peruvian, etc.
The main surface currents: in the northern part of the Pacific Ocean - warm Kuroshio, North Pacific and Alaskan and cold California and Kuril; in the southern part - warm South Trade winds and East Australian and cold West Winds and Peruvian. The water temperature at the surface at the equator is from 26 to 29 ° C, in the polar regions up to -0.5 ° C. Salinity 30-36.5 ‰. The Pacific Ocean accounts for about half of the world's fish catch (pollock, herring, salmon, cod, sea bass, etc.). Extraction of crabs, shrimps, oysters.
Important sea and air communications between the countries of the Pacific basin and transit routes between the countries of the Atlantic and Indian oceans run through the Pacific Ocean. Major ports: Vladivostok, Nakhodka (Russia), Shanghai (China), Singapore (Singapore), Sydney (Australia), Vancouver (Canada), Los Angeles, Long Beach (USA), Huasco (Chile). The date line passes through the Pacific Ocean along the 180 meridian.
Plant life (except for bacteria and lower fungi) is concentrated in the upper 200th layer, in the so-called euphotic zone. Animals and bacteria inhabit the entire water column and the ocean floor. Life develops most abundantly in the shelf zone and especially near the coast at shallow depths, where the flora of brown algae and a rich fauna of mollusks, worms, crustaceans, echinoderms, and other organisms are diversely represented in the temperate zones of the ocean. In tropical latitudes, the shallow water zone is characterized by the widespread and strong development of coral reefs, along the very coast - mangrove thickets. As we move from cold to tropical zones, the number of species increases sharply, and the density of their distribution decreases. In the Bering Strait, about 50 species of coastal algae are known - macrophytes, in the Japanese islands - over 200, in the waters of the Malay Archipelago - over 800. In the Soviet Far Eastern seas, there are about 4000 known species of animals, and in the waters of the Malay Archipelago - at least 40-50 thousand ... In the cold and temperate zones of the ocean, with a relatively small number of plant and animal species, due to the massive development of some species, the total biomass greatly increases; in the tropical zones, individual forms do not receive such a sharp predominance, although the number of species is very large.
With distance from the coasts to the central parts of the ocean and with increasing depth, life becomes less diverse and less abundant. In general, the fauna of T. o. includes about 100 thousand species, but of which only 4-5% are found deeper than 2000 m.At depths of more than 5000 m, about 800 species of animals are known, more than 6000 m - about 500, deeper than 7000 m - slightly more than 200, and deeper than 10 thousand m - only about 20 species.
Among the coastal algae - macrophytes - in the temperate zones, fucus and kelp are especially distinguished by their abundance. In tropical latitudes, they are replaced by brown algae - sargassus, green algae - kaulerpa and galimeda and a number of red algae. The surface zone of the pelagic zone is characterized by the massive development of unicellular algae (phytoplankton), mainly diatoms, peridiniaceae, and coccolithophorids. In zooplankton, the most important are various crustaceans and their larvae, mainly copepods (at least 1000 species) and euphausids; there is a significant admixture of radiolarians (several hundred species), coelenterates (siphonophores, jellyfish, ctenophores), eggs and larvae of fish and benthic invertebrates. In T. about. it is possible to distinguish, in addition to the littoral and sublittoral zones, a transition zone (up to 500-1000 m), bathyal, abyssal and ultraabyssal, or a zone of deep-sea trenches (from 6-7 to 11 thousand m).
Planktonic and benthic animals serve as abundant food for fish and marine mammals (nekton). The fish fauna is exceptionally rich, including at least 2,000 species in tropical latitudes and about 800 in the Soviet Far Eastern seas, where there are, in addition, 35 species of marine mammals. The greatest commercial value are: of fish - anchovies, Far Eastern salmon, herring, mackerel, sardine, saury, sea bass, tuna, flounder, cod and pollock; mammals - sperm whale, several species of minke whales, fur seal, sea otter, walrus, sea lion; invertebrates - crabs (including Kamchatka), shrimps, oysters, scallops, cephalopods and many others; from plants - kelp (seaweed), agaronos-anfeltia, zostera sea grass and phyllospadix. Many representatives of the Pacific Ocean fauna are endemic (pelagic cephalopod mollusk nautilus, most Pacific salmon, saury, green fishes, northern fur seal, sea lion, sea otter, etc.).
The great extent of the Pacific Ocean from North to South determines the diversity of its climates - from equatorial to subarctic in the North and Antarctic in the South.Most of the ocean surface, approximately between 40 ° north latitude and 42 ° south latitude, is located in the zones of equatorial, tropical and subtropical climates. The circulation of the atmosphere over the Pacific Ocean is determined by the main areas of atmospheric pressure: the Aleutian minimum, the North Pacific, South Pacific and Antarctic maximums. These centers of action of the atmosphere in their interaction determine the great constancy of northeastern in the North and southeastern in the South winds of moderate strength - trade winds - in the tropical and subtropical parts of the Pacific Ocean and strong westerly winds in temperate latitudes. Especially strong winds observed in the southern temperate latitudes, where the frequency of storms is 25-35%, in the northern temperate latitudes in winter - 30%, in summer - 5%. In the west of the tropical zone, from June to November, tropical hurricanes - typhoons are frequent. The northwestern Pacific Ocean is characterized by monsoon atmospheric circulation. The average air temperature in February decreases from 26-27 ° С near the equator to –20 ° С in the Bering Strait and –10 ° С near the coast of Antarctica. In August, the average temperature varies from 26-28 ° С near the equator to 6-8 ° С in the Bering Strait and to –25 ° С near the coast of Antarctica. Throughout the Pacific Ocean, located north of 40 ° S latitude, there are significant differences in air temperature between the eastern and western parts of the ocean, caused by the corresponding dominance of warm or cold currents and the nature of the winds. In tropical and subtropical latitudes, the air temperature in the East is 4–8 ° C lower than in the West. In the northern temperate latitudes, it is the other way around: in the east, the temperature is 8–12 ° C higher than in the West. Average annual cloudiness in areas of low atmospheric pressure is 60-90%. high pressure - 10-30%. Average annual precipitation at the equator is more than 3000 mm, in temperate latitudes - 1000 mm in the West. and 2000-3000 mm in V. The smallest amount of precipitation (100-200 mm) falls on the eastern outskirts of subtropical regions of high atmospheric pressure; in the western parts the amount of precipitation increases to 1500-2000 mm. Fogs are typical for temperate latitudes, they are especially frequent in the region of the Kuril Islands.
Under the influence of atmospheric circulation developing over the Pacific Ocean, surface currents form anticyclonic gyres in subtropical and tropical latitudes and cyclonic gyres in northern temperate and southern high latitudes. In the northern part of the ocean, the circulation is formed by warm currents: the North Passat - Kuroshio and the North Pacific and cold California currents. In the northern temperate latitudes, the cold Kuril Current dominates in the West, and the warm Alaskan Current in the East. In the southern part of the ocean, the anticyclonic circulation is formed by warm currents: the South Passat, East Australian, zonal South Pacific and cold Peruvian currents. North of the equator, between 2-4 ° and 8-12 ° north latitude, the northern and southern circulation during the year are separated by the Inter-trade (Equatorial) countercurrent.
The average temperature of the surface waters of the Pacific Ocean (19.37 ° C) is 2 ° C higher than the temperature of the waters of the Atlantic and Indian Oceans, which is a result of the relatively large size of that part of the Pacific Ocean area, which is located in well-warmed latitudes (over 20 kcal / cm2 per year ), and limited communication with the Arctic Ocean. The average water temperature in February varies from 26-28 ° С at the equator to -0.5, -1 ° С north of 58 ° north latitude, near the Kuril Islands and south of 67 ° south latitude. In August, the temperature is 25-29 ° С near the equator, 5-8 ° С in the Bering Strait and -0.5, -1 ° С south of 60-62 ° south latitude. Between 40 ° south latitude and 40 ° north latitude, the temperature in the eastern part of T. o. 3-5 ° C lower than in the western part. North of 40 ° north latitude - on the contrary: in the East, the temperature is 4-7 ° C higher than in the West. South of 40 ° south latitude, where zonal transport of surface waters prevails, there is no difference between water temperatures in the East and in the West. The Pacific Ocean has more precipitation than evaporated water. Taking into account the river flow, over 30 thousand km3 of fresh water flows here annually. Therefore, the salinity of the surface waters of T. o. lower than in other oceans (average salinity is 34.58 ‰). The lowest salinity (30.0-31.0 ‰ and less) is noted in the West and East of the northern temperate latitudes and in the coastal regions of the eastern part of the ocean, the highest (35.5 ‰ and 36.5 ‰) - respectively in the northern and southern subtropical latitudes. At the equator, the salinity of water decreases from 34.5 ‰ or less, in high latitudes - to 32.0 ‰ or less in the North, to 33.5 ‰ or less in the South.
The density of water on the surface of the Pacific Ocean increases fairly evenly from the equator to high latitudes in accordance with general nature temperature and salinity distributions: at the equator 1.0215-1.0225 g / cm3, in the North - 1.0265 g / cm3 and more, in the South - 1.0275 g / cm3 and more. The color of the water in subtropical and tropical latitudes is blue, the transparency in some places is more than 50 m.In the northern temperate latitudes, dark blue water predominates, at the coast - greenish, the transparency is 15-25 m.In the Antarctic latitudes, the water color is greenish, the transparency is up to 25 m ...
The tides in the northern part of the Pacific Ocean are dominated by irregular semidiurnal (height up to 5.4 m in the Gulf of Alaska) and semidiurnal (up to 12.9 m in the Penzhinskaya Bay of the Sea of Okhotsk). Near the Solomon Islands and off the coast of New Guinea, daily tides, up to 2.5 m. 40 ° north latitude. The maximum height of wind waves in the Pacific Ocean is 15 m and more, the length is over 300 m. Tsunami waves are characteristic, especially often observed in the northern, southwestern and southeastern parts of the Pacific Ocean.
Ice in the North Pacific Ocean is formed in seas with harsh winter climatic conditions (Beringovo, Okhotsk, Yaponskoe, Yellow) and in bays off the coast of Hokkaido Island, Kamchatka and Alaska peninsulas. In winter and spring, ice is carried by the Kuril Current into the extreme northwestern part of the Pacific Ocean, and small icebergs are found in the Gulf of Alaska. In the South Pacific, ice and icebergs are formed off the coast of Antarctica and are carried out into the open ocean by currents and winds. The northern boundary of floating ice in winter runs at 61-64 ° S, in summer it shifts to 70 ° S, icebergs are carried out to 46-48 ° S in late summer. Icebergs are formed mainly in the Ross Sea.
The Pacific Ocean is the largest ocean with the largest average and maximum measured depths. The marginal seas of the Pacific Ocean include: Bering, Okhotsk, Japanese, East China, Fillippin, South China, Coral and Tasmanovo, as well as other, smaller seas of Indonesia, the New Guinea and Solomono seas. In the Encyclopedia, the Arafura and Timor Seas refer to the seas of the Indian Ocean, and the Scotia Sea (also sometimes included in the Pacific Ocean) refers to the seas of the Southern Ocean. Sea Fiji Sea is included in the descriptions of the Southwest Pacific Ocean The border between the North and South Pacific is the equator; The Galapagos and Gilbert Islands, located at the equator, belong to the South Pacific Ocean.
Except for the marginal seas. The International Hydrographic Bureau distinguishes between individual marginal waters: the Gulf of Alaska (1533 thousand km3), Queen Charlotte, the Gulf of California (160 thousand km-) and the Bass Strait (70 thousand km2).
The Pacific Ocean extends 15,500 km from the Bering Strait to Cape Adair and 17,200 km from Panama to the island of Mindanao, or 24,000 km if this line is extended to the Gulf of Thailand. The area of the Pacific Ocean (together with the marginal seas) 169,000,000 km2, average depth 4028
The boundaries of the Pacific
The western border runs along the meridian from Singapore to Sumatra Island (Strait of Malacca) (according to Cossin) or along the northern edge of the Strait of Malacca (according to the International Hydrographic Bureau), or along the Lipni northwest of the Pedro Peninsula (according to Merchnson); then the border goes along the line of the island of Sumatra - the island of Java - the island of Roti - the island of Timor. Opinions are divided as to whether the Timor and Arafura Seas and the Gulf of Carpentaria should be attributed to the Indian Ocean basin or to the Pacific Ocean basin.Eastern border. All experts agree on the definition of Cape Horn as a boundary point. Further, the border goes along the 68 ° 04 "W meridian to the Antarctic Peninsula. The northern border runs with the Chukchi Sea.
Climate
In the northern hemisphere in winter in the Pacific Ocean, in comparison with other oceans, the greatest zonal stability of atmospheric processes is observed, which is determined by the almost symmetrical arrangement of the main centers of pressure in both hemispheres. In addition, the Pacific Ocean contains a zone of subtropical convergence with a wide belt of equatorial calm and two semi-permanent anticyclones: the North Pacific, or Hawaiian and South Pacific. In the summer of the northern hemisphere, these anticyclones intensify and their centers are located at 40 ° N. NS. and 30 ° S. NS. respectively. In the winter of the northern hemisphere, the North Pacific anticyclone weakens and shifts somewhat to the southeast. The South Pacific anticyclone does not change in the winter of the southern hemisphere. Due to the very cold Peruvian Current in the east and the increase in temperature under the influence of monsoons in the region of Australia and the Solomon Islands in the west, the South Pacific anticyclone is shifting to the east.Trade winds spread on both sides of the equator up to 25 °, the southeastern trade winds in the summer of the southern hemisphere shift somewhat north of the equator, in the same direction there is a slight displacement of the thermal equator. The trade winds in the Pacific are less constant and are usually weaker than the trade winds in other oceans. In the eastern Pacific, the trade winds are stronger and more noticeable. The thermal equator lies at about 5 ° N. sh., and very heavy rains are observed on this parallel.
Monsoons quite significant in both the northwestern and southwestern parts of the Pacific Ocean. In the northwestern part of the northern hemisphere in summer, the southeastern monsoon affects the entire Southeast East Asia, most of China and the marginal seas of the Pacific Ocean up to 145 ° E. etc. Mariana islands and even southward to the equator, where the same air current expands by the southeastern trade winds and the Australian anticyclone becomes the southeastern monsoon of East India. The Southwest Pacific Ocean is subject to the northwest monsoon in the summer of the southern hemisphere, which affects the climate of New Guinea, Northern Australia, the Solomon Islands, New Caledonia and, to a lesser extent, Fiji.
While over most of the eastern half of the Pacific Ocean there is very little seasonal shift in the boundaries of the trade winds, in the western half there is a 180 ° change in wind direction. This is most noticeable in the northwestern part of the Pacific Ocean, because in the winter of the northern hemisphere, the development of the Siberian anticyclone leads to a strong outflow of the very dry northwestern air, which creates a climate in Northeast China similar to that of the northeastern regions of the United States. But this climate is more severe, since the Canadian anticyclone only in rare cases is as strong as the Siberian one.
In the high latitudes of the North Pacific Ocean, a semi-permanent Aleutian cyclone (stronger in winter) is associated with the polar front, which often runs from Japan to Alaska, and westerly winds are enhanced by a strong winter runoff of cold air masses from Siberia. In summer, these conditions change due to a cyclone over Siberia and the Aleutian cyclone moves northward and becomes much weaker.
In the same latitudes of the South Pacific Ocean, the Australian anticyclone, as a rule, does not block western disturbances, because the polar front: passes mainly over the Southern Ocean, while heavy winter rains fall over Southeast Australia and the New Zealand islands. Between the islands of New Zealand and the coast of southern Chile, in the main belt of westerly winds, there is not a single island at a distance of 8000 km.
Pacific currents
The surface currents of the Pacific Ocean arise as a result of trade winds and westerly winds. The surface flow is mainly westerly at low latitudes and easterly at high latitudes. At the continents, zonal flows deviate to the north and south and form currents along the eastern and western boundaries of the Pacific Ocean. A system of cyclonic and anticyclonic gyres is formed along the equator.In the middle latitudes, large subtropical anticyclonic circulations prevail: western boundary currents (Kuroshio in the north and East Australian in the south. Parts of the current of the western wind drift, eastern boundary currents (California Current in the north. Peruvian in the south). Northern and southern trade winds with western direction located a few degrees north and south of the equator.
At the higher latitudes of the southern hemisphere, there is the Circumpolar Antarctic Current, which flows eastward around Antarctica, and in the northern hemisphere, the subarctic circular circulation, consisting of the Alaska Current, the Kuril Current (Oyashio), which runs southwest along Kamchatka and the Kuril Islands, and parts of the North Pacific Current.
In the area of the equator, the North and South Tradewinds run to the west, and between them in a strip of 5-10 ° N. NS. to the east there is an inter-trade countercurrent.
The highest speed is observed during the Kuroshio Current (more than 150 cm / s). Velocities up to 50 cm / s are observed in the western stream near the equator and in the Circumpolar Antarctic Current. Velocities from 10 to 40 cm / s occur on the eastern border of the California and Peruvian currents.
Subsurface countercurrents are found under the eastern boundary currents and along the equator. Under the California and Peruvian currents, there are currents 50-150 km wide, directed to the pole and extending from the horizon 150 m downward for several hundred meters. In the system of the California Current, the countercurrent appears on the surface also in the winter months.
The inter-trade subsurface countercurrent is a narrow (300 km wide), fast flow (up to 150 cm / s) going eastward at the equator under the western surface current. This current is located approximately at a depth of 50-100 m and extends from 160 ° E. to the Galapagos Islands (90 ° W).
Surface layer temperature changes from the freezing point at high latitudes to 28 ° C and more at low latitudes in winter. Isotherms are not everywhere directed in latitude, since some currents (Kuroshio, East Australian, Alaska) carry warmer water towards high latitudes, while other currents (California, Peruvian, Kuril) carry cold waters towards the equator. Moreover, the rise of cold deep water in the eastern boundary currents and at the equator also affects the distribution of heat.
Salinity of water the surface layer reaches a maximum in mid-latitudes, where evaporation exceeds precipitation. The highest salinity values are somewhat higher than 35.5 and 36.5 prom. respectively in the northern and southern subtropical anticyclonic circulations. Salinity is much lower in high and low latitudes, where precipitation exceeds evaporation. The salinity of the waters of the open ocean is 32.5 prom. in the north and 33.8 prom in the south (near Antarctica). Near the equator, the lowest salinity values (less than 33.5 prom.) Are noted in the eastern part of the Pacific Ocean. Redistribution of salinity occurs under the influence of circulation. The California and Peruvian currents carry low salinity waters from high latitudes towards the equator, and the Kuroshio carries high salinity waters from the equator towards the pole; subtropical closed circuits are like lenses of high salinity water, surrounded by waters of "low salinity."
The oxygen concentration in the surface layer is always very close to saturation, since the upper layers are in contact with the atmosphere. The amount of saturation depends on both temperature and salinity, but the role of temperature is much greater, and the overall distribution of oxygen on the surface largely reflects the distribution of temperature. Oxygen concentration is high in cold waters of high latitudes and low in warm equatorial waters. At greater depths, the oxygen concentration decreases. The degree of oxygen saturation is used as an indicator of the "age" of water - the time elapsed since the last contact of water with the atmosphere.
Circulation of the upper layers of water occurs under the influence of the wind. The adaptation of the density field to geostrophic equilibrium, as well as convergence and divergence caused by the wind, lead to the formation of deep flows that are completely different from the surface ones. At great depths, where the circulation is mainly thermohaline, the differences are even greater in subtropical anticyclonic circulations caused by wind, there is a convergence of the water surface, and the accumulation of water leads to the formation of a mixed layer (up to 300 m thick in the western part of the Pacific Ocean in winter). Similarly, the divergence of surface waters in high-latitude cyclonic circulations leads to the rise of deep waters to the surface, and then to their spread to the periphery of the cyclones. Along the coasts of North and South America in mid-latitudes, winds directed towards the equator force surface waters to move from the coast, as a result of which deep waters rise to the surface. At the equator, westerly winds and Earth's rotation cause surface water to move from the equator both southward and northward. which also leads to the rise of deep waters. Anticyclonic circulations are thus large lenses of less dense water. They are supported by the convergence of waters caused by wind, as well as by heating and evaporation.
In the subtropics of the Pacific Ocean, lenses of warm salt water extend downward to a depth of more than 500 m. As a result, lenses of cold water of low salinity are formed here. A similar picture, albeit to a lesser extent, is characteristic of the equatorial region.
Characteristics of water masses and deep circulation. In the high latitudes of the North Pacific, surface waters are so low saline that even cooling to the freezing point will not give them sufficient density to sink deeper than the 200 m horizon.The deep waters of the North Pacific come from the South Pacific (since water exchange with the Arctic the ocean is small). These deep waters, which form in the Weddell Sea in the North Atlantic (where a certain ratio of temperature and salinity forms very dense water at the surface), is constantly replenishing.
Oxygen enters the ocean surface from the atmosphere. The waters plunging into the Weddell Sea in the North Atlantic are oxygen-rich and oxygenate the deep waters of the Pacific Ocean as they move north. Compared to the high oxygen content on the surface and at the bottom, the oxygen content at intermediate the northern part of the Pacific Ocean is almost completely devoid of oxygen.
Distribution of nutrients in the Pacific Ocean depends on the water circulation system. Inorganic phosphates are consumed during the growth of plants on the surface and are regenerated at great depths during the immersion and decomposition of plants. As a result, there are usually more nutrients at depths of 1 to 2 km than at the surface. The deep waters of the Pacific Ocean are richer in phosphates than those of the Atlantic. Since the outflow of waters from the Pacific Ocean is mainly due to surface waters, which are poorer in phosphates, phosphates accumulate in the Pacific Ocean, and their average concentration is about twice as high as in the Atlantic.
Bottom sediments
The longest sediment columns, taken from the bottom of the Pacific Ocean, reached 30 m, but most of the columns were no more than 10 m. Experimental deep-water drilling in two areas - near San Diego (California) and near Guadalupe Island - made it possible to significantly increase the depth of research.
The total thickness of sediments in the Pacific Ocean is unknown; however, according to geophysical data, a layer of unconsolidated sediments is about 300 m. Below this layer there is a second layer about 1 km thick, which is represented by consolidated sediments and volcanic rocks, but a more complete picture of these two layers can be obtained only as a result of deep water drilling. While drilling on the Mohol project off the coast of Southern California, basalt was discovered under a 200-meter layer of sediment.
Volcanic precipitation
In some parts of the Pacific Ocean, layers of sediment are found, almost entirely consisting of fragments of unaltered volcanic rocks. Such material may apply to large area in case of surface eruptions. During underwater eruptions, the area of distribution of such sediments will be much smaller. Underwater alteration of volcanic silt and its mixing with other sediments leads to the formation of a continuous series of intermediate sediment varieties of mixed origin. For volcanic sediments, the parent lavas are of the andesite and rhyolite type, because their eruption is explosive and they are sufficiently resistant to secondary changes. The sediments near Indonesia, Central America and the Gulf of Alaska contain significant amounts of this kind of material. Basalt volcanic sediments are found locally, due to the fact that the volcanic material of the basic composition, in comparison with the acidic, rapidly decomposes with the formation of autogenous minerals. The alteration of glassy debris is one of the most important reactions resulting in the formation of aluminosilicates found in the near-surface sediments of the oceans.
Coral reefs
Coral reefs are wave-resistant ecological elements, consisting mainly of hermatip corals and calcareous algae. Coral reefs border the continents and islands of the Pacific Ocean in areas where the temperature is not less than 18 ° C. In the sediments of reef lagoons, fragments of corals, foraminifera and fine-grained carbonate silt are found. Reef debris extends along the edges of oceanic islands to abyssal depths, where they undergo the same dissolution processes as foraminiferal calcium carbonate. Dolomite has been found at a certain depth on some coral islands. it is also found in abyssal sediments near coral islands and is probably formed from calcium carbonate supplied from them, which is burned up in deep-sea areas. In areas where there is little rainfall, coral rocks, as a result of reaction with phosphate from guano, are modified into phosphate rocks, consisting of apatite. The Lower Eocene phosphotized fauna was found at Guyot Sylvania. There are also reactions of calcium carbonate with phosphates dissolved in seawater; Early Eocene phosphatized fauna was found on Guyot Sylvania.The history of the development of the Pacific Ocean
For more than a hundred years, scientists have been trying to solve one of the greatest mysteries of geology - to reconstruct the tectonic history of the Pacific Ocean. By its size, structure, paleogeography, the Pacific Ocean differs from all other oceans of the globe.The Pacific Ocean is the largest ocean on earth, with many more volcanoes, seamounts and atolls on its bottom than all other oceans combined. The Pacific Ocean is surrounded on all sides by the longest continuous belts of folded mountains, teeming with active volcanoes, where earthquakes occur more often than in any other region of the globe. The propagation of seismic waves under the crust of the Pacific Ocean occurs at a shallower depth from the surface and at a higher speed than in other oceans.
The bottom of the central part of the ocean is covered with more thin layer precipitation than in other oceans, so here you can better study the features of the underlying crust. All these features are enough to show why geologists and geophysicists consider the Pacific Ocean to be unique in geotectonic terms.
Geotectonic zoning within the Pacific Ocean clearly distinguishes between two physical and geographical provinces: 1) main, or central. Pacific Basin and 2) marginal seas with numerous ridges and depressions of the second order located within their boundaries.
Pacific basin
On the whole, the bottom of the Pacific Ocean is a gently undulating abyssal plain; its individual parts are exclusively aligned for tens, and sometimes hundreds of kilometers. Its average depth is 5000 m.
This plain is traversed by numerous seamounts or volcanic ridges and innumerable uplands from small hills to rather massive (conical) seamounts. The East Pacific Rise, which is a continuation of the mid-ocean ridge, extends from Antarctica to the southern tip of New Zealand, capturing the Pacific-Antarctic ridge. Easter Island Rise and Galapagos Rise, and ends at America in the Gulf of California. In terms of its geomorphological features, this uplift is similar to other mid-oceanic ridges of the Atlantic and Indian Oceans, but in its shape it is surprisingly asymmetric and noticeably deviates towards the American continent. Small forms of its relief are the same as in other underwater ridges of this type. The ridge is marked by a narrow rift or a series of graben structures, and most of the slopes are complicated by irregular (approximately 1000 km) ridges and grooves located parallel to the uplift axis. The average height of these ridges is 2000-3000 m from the bottom level of the central part of the Pacific Ocean; in addition, it also includes local clusters of small volcanic islands and seamounts. It can be assumed that the Juan de Fuca Ridge near Vancouver Island is a continuation of the main ridge.
Submarine fan and abyssal plains
Almost along the entire northeastern edge of the ocean, there are numerous fans, rather large, which in some places turn into abyssal plains. However, the number of the latter in the Pacific Ocean is small, since usually narrow oceanic trenches act as "traps" for sedimentary material, preventing further movement of turbidity flows.
Archipelagos of the Western and Central Pacific Ocean with volcanic islands, underwater uplifts and atolls. This area is characterized by rectilinear subparallel belts of volcanic islands, underwater ridges and atolls. Fan-shaped from the foot of these underwater ridges diverge sediment cones, which everywhere form slightly inclined slopes, gradually merging with the ocean floor (about 5000-6000 m). An interesting feature of most underwater ridges (an example is the ridge, the peaks of which are represented by the Hawaiian Islands) is the presence of shallow-water depressions, which almost completely surround the island slopes.
Archipelagos of the Central Pacific Ocean occupy 13.7% of its area. The height of the islands is different. An example of high islands is the Tahiti chain, while the parallel Tuamotu chain is under water and on the surface is represented only by atolls. Main plain with low relief. It occupies most of the Pacific Ocean at a depth of 5000-6000 m. This plain is extremely flat, and here there are no gentle slopes, typical of the abyssal plains, directed in one direction. The relief of the plain has a rather wavy character and is a system of conjugated low ridges and shallow depressions with elevations of about 300 m and distances between the tops of the ridges of about 200 km. In some areas, the maximum relative excess does not even reach 60 m, while in others it can reach 500 m or more. Individual underwater ridges occasionally rise above the surface of the plain, but their number is small, with the exception of certain sections — island arcs or such specific provinces as the Gulf of Alaska.
Fault zones (linear scarps)
The zones of large faults stretch for long distances (up to 2000 km), they cross the low relief plains of the northeastern sector of the Pacific Ocean and the East Pacific Rise.
Peripheral zone of island arcs and grooves
The boundaries of the main part of the Pacific Basin are fixed, as a rule, by the zone of deep-sea trenches; on the mainland side, these troughs are bordered by rocky mountains or arcs of islands connected with one or more underwater ridges. In the western part of the Pacific Ocean, these island arcs and troughs are isolated and separated from the continents by intermediate depressions, as a result of which the influx of sediments into the troughs is negligible, and they remain mostly unfilled sediments. These western trenches are extremely narrow, with a flat bottom due to little sediment input. The slopes are steep, the steepness is 25-45 °.
Along the eastern edge of the Pacific Ocean, the coastal Cordillera are cut by large rivers carrying large amounts of sedimentary material into the depressions, in some cases completely filling them. The island arcs themselves are located on a double ridge; the outer islands are non-volcanic in nature, or at least not active volcanoes, while the inner zone contains many active or recently extinct volcanoes. This is the so-called famous "fire belt" of the Pacific Ocean.
Marginal seas
They are located only in the western part of the Pacific Ocean and separate the island arcs from the mainland. There are several secondary inland seas, they reach 500-1000 km in width and about the same in length. The bottom topography of these seas is extremely diverse and, like the main basin, reflects their tectonic history and existing sources of drift. According to sounding data, the following main types of relief are distinguished.
Volcanic hills- an extremely chaotic jumble of hills with steep, steep slopes, similar to volcanic cones, which completely cover the bottom of more distant depressions, such as, for example, the Pandora depression.
Abyssal plains- flat, level or slightly sloping plains covered with sediments brought by fast bottom currents, for example turbidity. It is difficult to imagine how otherwise such plains could have formed. In addition, a surface of this type is always somewhat higher (50-100 m) in the place where sediments from the mainland enter the sea. For example, the Tasman Basin is slightly shallower in the northwest, just opposite the Sydney, Hawkesburn and Hunger rivers, which flow into it. A similar shallow water is found in the northeast of the Fiji Sea, where the Rewa (powerful tropical stream) flows into it, pouring out from the Fiji Islands. The largest of the basins of this type has a depth of up to 5000 m, the smaller basins are characterized by the smallest depths - from 2000 to 4000 m.
Areas of microcontinental blocks found in numerous areas; they represent a heap of quasi-crate blocks of large and small sizes, sometimes the distance between these areas is only a few kilometers, but more often they are separated from each other by hundreds of kilometers. The Melanesian Plateau is a complex of this type.
Underwater plateaus widespread in the Pacific Ocean at shallow to medium depths. The plateau is separated from the continents. Typical examples: the Coral Sea plateau, the Belloy plateau in the southwestern part of the Pacific Ocean. Their usual depth is 500-2000 m; numerous coral atolls rise from the surface of the plateau.
Ridges and uplifts of the transition zone... The entire region is crossed by positive structures: either wide dome-shaped uplifts, or narrow, strongly dissected ridges. Small volcanoes, seamounts and sometimes atolls are confined to these structures. The main line of the ridges is almost continuous and runs almost parallel to the main peripheral belt of island arcs and troughs. Some of them end on the surface with islands such as Japanese, Philippine, New Guinea, New Caledonia, New Zealand, etc.
Troughs and deep-sea depressions transition zones are usually associated with the aforementioned positive landforms. They usually occur in pairs, i.e., a large uplift usually corresponds to an equally large parallel depression. Interestingly, a trench or depression is usually located on the continental side of the ridge at the bottom of the Mediterranean or marginal sea, i.e., they have a completely opposite orientation than
peripheral belt of the central part of the Pacific Ocean.
Features of the structure of the Pacific Ocean... The Pacific Ocean differs in many ways from the rest of the world's oceans; it has given its name to three concepts: Pacific coastlines, Pacific volcanism, and Pacific crust.
Pacific coastlines... A characteristic feature of Atlantic-type coasts is that the coastline cuts off the tectonic structures of the mainland; this is due to faults extending along the coasts with subsidence of individual large tectonic blocks or, generally speaking, with disruptions of continuous structures that originally extended from the mainland into the ocean. In contrast to the Atlantic, the Pacific type of coasts reflects continuous, continuous linear strikes of the Pacific systems of folded mountains, island arcs and adjacent marginal depressions. The Pacific Ocean is a submerged foreland, on which peripheral fold belts are piled up. The main distinguishing feature of the Pacific type of coasts is parallelism, that is, mountains, coasts, beaches, reefs, troughs tend to maintain linearity and are located on the periphery relative to the central part of the Pacific Ocean.
Parallel ancient terraces of varying heights run along the main line of the Pacific coastline; sometimes within a few kilometers the altitude changes by 1000 m. The main tendency of the relief is positive. Secondary terraces of the Pacific type are less active, but their height is also unstable; Pliocene terraces of Southeast Australia can reach heights of 2000 m (southern part of New South Wales). However, most of the coastline of the secondary type is characterized by faults, negative forms of relief prevail.
Pacific volcanoes Pacific lavas are mainly confined to the belts of the Circum-Pacific folding, and not to the central part of the Pacific Ocean. The main rocks are andesites, rhyolites and olivine basalts. The Atlantic type of volcanism is characterized by alkaline lavas; it is regionally associated with zones of stretch or crumpling.
Pacific crust. Based on geophysical studies of the earth's crust, it has been established that the nature of the Pacific crust is somewhat specific, although there are areas with similar structures in other oceans. The most significant fluctuations in gravity values were recorded by Vening-Meines over the peripheral arcs. Based on the data obtained, it can be assumed that there is an uncompensated mass deficit along the troughs and an excess mass under the island arcs. Mid-oceanic ridges are characterized by the presence of lighter material in powerful "roots".
Analysis of seismic data on earthquakes and sounding data shows that under a layer of water 5-6 km thick in the central part of the Pacific Ocean lies a layer of sediments with a thickness of 0.5-1.0 km - the "second layer" is, apparently, water-bearing igneous rocks serpentinite type; however, some geologists believe that this layer is formed by consolidated sediments. The second layer lies at the section of the Mohorovichich surface
Systematic surveys with a towed magnetometer in the northeastern Pacific showed the presence of alternating strongly and weakly magnetized rocks, oriented from north to south, which had lateral displacement due to large latitudinal faults.
The crust is of an intermediate type in the western part of the Pacific Ocean. A wide zone of marginal seas stretching along the western borders of the Pacific Ocean from the Bering and Okhotsk to the Coral and Tasman seas is perhaps one of the most interesting features of the Pacific Ocean. And in other oceans there are marginal seas, but in no ocean are these seas so large and not so numerous; in addition, they are not located anywhere but the Pacific Ocean along the western border.
It is quite clear that the general geology of these marginal seas in the western part of the Pacific Ocean is fundamentally different from the geology of the central part of the Pacific Ocean. The line between these two provinces in the western part of the Pacific Ocean also separates two huge physical and geographical regions: the central part of the Pacific Ocean and the western marginal seas.
Deep sea trenches and island arcs... The main part of the Pacific Ocean has another significant feature: an almost continuous belt of trenches or ditches runs along the chain of island arcs on the oceanic side and the coastal Cordillera. Similar landforms exist locally in other oceans, but they do not form a peripheral belt there. Strong negative gravity anomalies correspond to these belts. A belt of positive gravitational anomalies passes behind these belts on the continental side. Similar belts of positive and negative anomalies are found in other oceans, but they are especially widespread in the Pacific Ocean. Several important points in the distribution of the Pacific island arcs should be highlighted.
Island arcs found only in the western part of the Pacific Ocean, in the east they correspond to the coastal cordillera. Thus, both of these forms are similar in the geotectonic sense, but they are not identical, since there are marginal seas that are located between the continents and island arcs. Such seas are also found inside the arcs of the Antilles and Scotia, which are quasi-Pacific structures extended towards the Atlantic Ocean.
Island arcs usually consist of two rows of islands, with the outer line being mainly non-volcanic islands, while the islands in the inner line being mostly volcanoes. On the outer arc, there are Mesozoic sediments, dislocated and broken by faults. The distance between the rows is usually 50-150 km. In some cases, volcanoes on one of the arcs are completely absent. The "Fire Belt" of the Pacific Ocean is not continuous everywhere.
Island arcs, as the name implies, have the shape of a semicircle. The bending radius varies from 200 to 2000 km. However, in some cases, such as the Tonga and Kermadec Troughs, both rows of islands are straight-line. Deep-sea trenches and arcs are complexly interconnected with the seismic zone, which is one of the most intense seismic belts in the world.
The wake of the so-called uplifting fault surface generally represents a uniform distribution of earthquake foci along the downtime plane, but the epicenters do not really clearly reflect the levels of earthquake quakes. Some geologists believe that earthquake tremors are accompanied by faults, and many large trough zones in the western Pacific are now well correlated with horizontal offset faults.
Stability of the Pacific The question of the constancy of continents and oceans belongs to the philosophical aspect of geology. It was put forward for discussion in the last century, but has not yet been decided. This issue is considered from three points of view: 1) biogeographic, 2) geochemical and geophysical, 3) geotectonic. Each of these points of view needs careful analysis.
Biogeographic transoceanic links... At the 1971 Pacific Congress in Honolulu, a large number of biogeographers strongly advocated the idea of the Polynesian mainland, agreeing at least only for wide land bridges between the now completely isolated islands. This entire area was formerly a mainland, which subsequently split into numerous groups of islands; the Hawaiian Islands were the first to secede. Deep drilling of the Central Pacific Atolls has discovered typical land snails at levels dating back to different eras, up to the Miocene at least (eg, 251 and 552 m).
The “island steps” that existed in ancient times, which are still encountered today, facilitated the migration of certain species from island to island. The Galapagos Islands rise at the intersection of the East Pacific Rise and short secondary ridges leading to Central and South America.
The Swedish botanist Scottsberg has dedicated his life to studying the flora of the Pacific islands; on the basis of observational data, he came to the conclusion that there was once a Pacific flora, autochthonous (local), continental, not associated with either the flora of North America, or with the flora of any other neighboring continent.
The existing landforms in the area of New Guinea, New Zealand, the Philippines and Fiji Islands are good evidence of the existence of connections between the continents (this can include shallow submarine ridges and platforms); in addition, good geological data are available.
The theory of the existence of a continental bridge or isthmus is well suited to explain marginal migrations along the entire periphery of the Pacific Ocean through the Aleutian Islands to the Bering Strait, through the Antilles and from South America to Australia and New Zealand. Geotectonics in most cases does not contradict the presence of such connections. When explaining migration along the transantarctic line, two serious questions arise: the area between the Ross Sea and New Zealand. Tectonic structures of South America, extending through the Scotia arc, connect with the Mesozoic folds of West Antarctica, but then abruptly break off at the Ross Sea. Not a single ridge extends from the Ross Sea to New Zealand or Australia. Here, apparently, there was a separation of the bark;
Geographical position. The Pacific (or Great) Ocean in terms of its size and characteristics of nature is a unique natural object of our planet. The ocean is located in all hemispheres of the Earth, between the continents of Eurasia and Australia in the west, North and South America in the east and Antarctica in the south.
The Pacific Ocean occupies more than 1/3 of the planet's surface and almost half of the World Ocean (Table VII.3). It has an oval shape, stretches somewhat from northwest to southeast, and is widest between the tropics. The coastline is relatively straight off the coast of North and South America and is highly dissected off the coast of Eurasia. The Pacific Ocean includes a number of marginal seas of East and Southeast Asia. The ocean contains a large number of archipelagos and individual islands studied within Oceania.
Table VII.3
General information about the oceans
Oceans Area, million km3 Volume,
million km3 Average
depth, m
depth, m World Ocean 361.10 1340.74 3700 11022 (Mariana Trench) Quiet 178.62 710.36 3980 11022 (Mariana Trench) Atlantic 91.56 329.66 3600 8142 (Puerto Rico Trench) Indian 16.17 282 , 65 3710 7729 (Sunda Trench) Northern Arctic
14,75
18,07
1220
5527 (Greenland Sea)
Bottom relief. The Pacific Ocean is the deepest. Its bottom relief is complex. The shelf (continental shelf) occupies a relatively small area. Off the coast of North and South America, its width does not exceed tens of kilometers, and off the coast of Eurasia, the shelf is measured in hundreds of kilometers. Deep-sea trenches are located in the marginal parts of the ocean, and the main part of the deep-sea trenches of the entire World Ocean is located in the Pacific Ocean: 25 out of 35 have a depth of more than 5 km; and all the troughs, more than 10 km deep, - such 4. Large uplifts of the bottom, individual mountains and ridges divide the ocean floor into hollows. In the southeast of the ocean, the East Pacific Rise is located, which is part of the global system of mid-ocean ridges.
An almost continuous chain of active volcanoes forming the Pacific Ring of Fire is connected with the system of deep-sea trenches and mountain structures on the continents and islands adjacent to the ocean. In this zone, ground and underwater earthquakes are also frequent, causing giant waves - tsunamis.
Climate. The Pacific Ocean stretches from subarctic to subantarctic latitudes, that is, it is located in almost all climatic zones of the Earth. Its main part is located in the equatorial, subequatorial and tropical zones of both hemispheres. The air temperature over the water area of these latitudes all year round is from +16 to + 24 ° С. However, in the north of the ocean in winter, it drops below 0 ° C. Off the coast of Antarctica, this temperature persists in the summer months.
The circulation of the atmosphere over the ocean is characterized by zonal features: westerly winds prevail in temperate latitudes, trade winds prevail in tropical latitudes, and monsoons are pronounced in subequatorial latitudes off the coast of Eurasia. Over the Pacific Ocean, strong winds of storm force and tropical cyclones - typhoons are frequent. The maximum amount of precipitation falls in the western parts of the equatorial belt (about 3000 mm), the minimum - in the eastern regions of the ocean between the equator and the southern tropic (about 100 mm).
Currents. The Pacific Ocean is quite elongated from west to east and therefore latitudinal water flows prevail in it. In the ocean, two huge rings of water movement are formed: north and south. The northern ring includes the North trade wind, the Kuroshio, the North Pacific and California currents. The southern ring is made up of the South Passat, East Australian, West Winds and the Peruvian current. Currents have a significant impact on the redistribution of heat in the ocean and on the nature of adjacent continents. Thus, trade wind currents drive away warm waters from the western tropical coasts of the continents to the eastern ones, therefore, in low latitudes, the western part of the ocean is much warmer than the eastern one. In the middle high latitudes, on the contrary, the eastern parts of the ocean are warmer than the western ones.
Water properties. All types of surface water masses, except arctic ones, are formed in the Pacific Ocean. Because of the large area of the ocean between the tropics, its surface waters are warmer than other oceans. The average annual water temperature between the tropics is + 19 ° С, in equatorial latitudes - from +25 to + 29 ° С, near the coast of Antarctica - it drops to -1 ° С. Precipitation over the ocean generally predominates over evaporation. The salinity of the surface waters of the Pacific Ocean is slightly lower than in the Atlantic, since the western part of the ocean receives a lot of fresh river waters (Amur, Yellow River, Yangtze, Mekong and others). Ice phenomena in the northern part of the ocean and in the subantarctic belt are seasonal. Off the coast of Antarctica, sea ice stays all year round. Antarctic icebergs with surface currents rise to 40 ° S latitude.
The organic world. In terms of biomass and number of species, the organic world of the Pacific Ocean is richer than in other oceans. This is due to its long geological history, enormous size, and a variety of environmental conditions. Organic life is especially rich in equatorial-tropical latitudes, in areas where coral reefs develop. There are many different types of salmon fish in the northern part of the ocean.
The fish catch in the Pacific Ocean accounts for more than 45% of the world production. The main fishing areas are areas of interaction between warm and cold waters; shelf areas in the west of the ocean and areas of uplift of deep waters off the coast of North, and especially South America.
Natural complexes. In the Pacific Ocean there are all natural belts, except for the north polar one.
The North Polar Belt occupies a small part of the Bering and Okhotsk Seas. In this belt, there is an intensive circulation of waters, so they are rich in fish. The northern temperate belt occupies vast areas. It is characterized by the interaction of warm and cold water masses. This contributes to the development of the organic world. In the west of the belt, a unique aquatic complex of the Sea of Japan is formed, which is distinguished by a large species diversity.
The northern subtropical belt in the Pacific Ocean is not as pronounced as the temperate one. The western part of the belt is warm, while the eastern part is relatively cold. The waters are poorly mixed, blue, transparent. The number of plankton and fish species is small.
The northern tropical belt is formed under the influence of the powerful North Passat Current. There are many individual islands and archipelagos in this belt. The productivity of the waters of the belt is low. However, near seamounts and islands, where the vertical movement of water increases, accumulations of fish and other marine organisms appear.
In the equatorial belt, a complex interaction of winds and various currents is observed. At the boundaries of streams, eddies and gyres contribute to the rise of water, therefore, their biological productivity increases. The richest in life are aquatic complexes near the Sunda Islands and the shores of northeastern Australia, as well as complexes of coral reefs.
In the southern hemisphere in the Pacific Ocean, similar natural belts are formed as in the northern one, but they differ in some properties of water masses and in the composition of organisms. For example, notothenium and white-blooded fish live in the waters of the subantarctic and antarctic belts. In the southern tropical zone between 4 and 23 ° S lat. a special aquatic complex is being formed off the coast of South America. It is characterized by a steady and intense rise of deep waters (upwelling), active development of organic life. This is one of the most productive areas of the entire World Ocean.
Household use. The Pacific Ocean and its seas wash the coasts of the continents, on which there are more than 30 coastal states with a total population of about 2 billion people. The main types of natural resources of the ocean are its biological resources. Ocean waters are characterized by high productivity (about 200 kg / km2). In recent years, the Pacific Ocean has been ranked first in the world for the production of fish and seafood. Extraction of minerals began on the ocean shelf: deposits of oil and gas, tin ores and other non-ferrous metals; table and potassium salts, magnesium, bromine are obtained from sea water. World and regional shipping routes pass through the Pacific Ocean; a large number of ports are located on the shores of the ocean. The most important lines run from the coast of North America to the Far East coast of Asia. The energy resources of the Pacific waters are large and varied, but they are still underutilized.
Human economic activity has led to severe pollution of some waters of the Pacific Ocean. This was especially evident off the coast of Japan and North America. The stocks of whales were depleted, a number of valuable species fish and other animals. Some of them have lost their former commercial value.
§ 8. Atlantic Ocean
Geographical position. The Atlantic Ocean stretches from north to south for 16 thousand km from subarctic to Antarctic latitudes. The ocean is wide in the northern and southern parts, narrowing in equatorial latitudes up to 2900 km. In the north it is connected with the Arctic Ocean, and in the south it is widely connected with the Pacific and Indian Oceans. It is bounded by the shores of North and South America in the west, Europe and Africa in the east and Antarctica in the south.
The Atlantic Ocean is the second largest of the world's oceans. The ocean coastline in the northern hemisphere is heavily dissected by numerous peninsulas and bays. There are many islands, inland and marginal seas near the continents. The Atlantic includes 13 seas, which occupy 11% of its area.
Bottom relief. The Mid-Atlantic Ridge runs across the entire ocean (approximately at an equal distance from the coasts of the continents). The relative height of the ridge is about 2 km. Transverse faults divide it into separate segments. In the axial part of the ridge, there is a giant rift valley 6 to 30 km wide and up to 2 km deep. Both underwater active volcanoes and the volcanoes of Iceland and the Azores are confined to the rift and faults of the Mid-Atlantic Ridge. On both sides of the ridge, there are basins with a relatively flat bottom, separated by elevated uplifts. The shelf area in the Atlantic Ocean is larger than in the Pacific.
Mineral resources. Oil and gas reserves have been discovered on the shelf of the North Sea, in the Gulfs of Mexico, Guinea and Biscay. Phosphorite deposits have been discovered in the area of uplift of deep waters off the coast of North Africa in tropical latitudes. Placer deposits of tin near the shores of Great Britain and Florida, as well as diamonds off the coast of South-West Africa, have been identified on the shelf in the sediments of ancient and modern rivers. Ferromanganese nodules are found in bottom basins off the coasts of Florida and Newfoundland.
Climate. The Atlantic Ocean is located in all climatic zones of the Earth. The main part of the ocean is between 40 ° N latitude. and 42 ° S. - is located in subtropical, tropical, subequatorial and equatorial climatic zones. There are high positive air temperatures all year round. The sub-Antarctic and Antarctic latitudes have the most severe climate, and to a lesser extent, the sub-polar, northern latitudes.
Currents. In the Atlantic, as in the Pacific, two rings of surface currents are formed. In the northern hemisphere, the North Passat Current, the Gulf Stream, the North Atlantic and Canary currents form a clockwise movement of waters. In the southern hemisphere, the South Tradewinds, Brazilian, Westerly and Benguela winds form counterclockwise water movement. Due to the considerable length of the Atlantic Ocean from north to south, meridional water flows are more developed in it than latitudinal ones.
Water properties. The zoning of water masses in the ocean is complicated by the influence of land and sea currents. This is manifested primarily in the distribution of surface water temperatures. In many areas of the ocean, the isotherms near the coast deviate sharply from the latitudinal direction.
The northern half of the ocean is warmer than the southern, the temperature difference reaches 6 ° C. The average surface water temperature (16.5 ° C) is slightly lower than in the Pacific Ocean. The cooling effect is provided by the waters and ice of the Arctic and Antarctic. The salinity of surface waters in the Atlantic Ocean is high. One of the reasons for the increased salinity is that a significant part of the moisture evaporating from the water area does not return back to the ocean, but is transferred to neighboring continents (due to the relative narrowness of the ocean).
A lot flows into the Atlantic Ocean and its seas big rivers: Amazon, Congo, Mississippi, Nile, Danube, La Plata, etc. They carry huge masses of fresh water, suspended material and pollutants into the ocean. In freshened bays and seas of subpolar and temperate latitudes, ice forms near the western coast of the ocean in winter. Numerous icebergs and floating sea ice impede shipping in the North Atlantic Ocean.
The organic world. The Atlantic Ocean is poorer in flora and fauna than the Pacific Ocean. One of the reasons for this is its relative geological youth and a noticeable cooling in the Quaternary period during the glaciation of the northern hemisphere. However, in quantitative terms, the ocean is rich in organisms - it is the most productive per unit area. This is primarily due to the widespread development of shelves and shallow banks, which are home to many bottom and bottom fish (cod, flounder, perch, etc.). Biological resources The Atlantic Ocean is depleted in many areas. The ocean's share of global fisheries has declined significantly in recent years.
Natural complexes. In the Atlantic Ocean, all zonal complexes are distinguished - natural belts, except for the northern polar one. The waters of the northern subpolar belt are rich in life. It is especially developed on the shelves off the coasts of Iceland, Greenland and the Labrador Peninsula. The temperate zone is characterized by an intense interaction of cold and warm waters, its waters are the most productive regions of the Atlantic. Vast expanses of warm waters of two subtropical, two tropical and equatorial zones are less productive than the waters of the northern temperate zone.
In the northern subtropical zone, a special natural aquatic complex of the Sargasso Sea stands out. It is characterized by increased salinity of waters (up to 37.5 ppm) and low biological productivity. Brown algae - sargassums, which gave the name of the water area, grow in clear water of pure blue color.
In the temperate zone of the southern hemisphere, as well as in the northern, natural complexes are rich in life in areas where waters mix with different temperatures and water densities. The subantarctic and Antarctic belts are characterized by the manifestation of seasonal and permanent ice phenomena that affect the composition of the fauna (krill, cetaceans, notothenium fishes).
Household use. All types of human economic activities in marine areas are represented in the Atlantic Ocean. Among them, sea transport is of the greatest importance, followed by subsea oil and gas production, and only then is the catch and use of biological resources.
More than 70 coastal countries with a population of over 1.3 billion people are located on the shores of the Atlantic. Many transoceanic routes with large volumes of freight and passenger traffic pass through the ocean. The most significant ports in the world in terms of cargo turnover are located on the coasts of the ocean and its seas.
The already explored mineral resources of the ocean are significant (examples are given above). However, oil and gas fields are currently being intensively developed on the shelf of the North and Caribbean Seas, in the Bay of Biscay. Many countries that previously did not have significant reserves of these types of minerals are now experiencing economic growth due to their extraction (England, Norway, the Netherlands, Mexico, etc.).
The biological resources of the ocean have been used intensively for a long time. However, due to overfishing of a number of valuable commercial fish species, in recent years the Atlantic has been inferior to the Pacific Ocean in terms of fish and seafood production.
Intensive human economic activity in the Atlantic Ocean and its seas causes a noticeable deterioration of the natural environment - both in the ocean (water and air pollution, a decrease in the stocks of commercial fish species) and on the coasts. In particular, recreational conditions on the shores of the ocean are deteriorating. In order to prevent further and reduce the existing pollution of the natural environment of the Atlantic Ocean, scientific recommendations are being developed and international agreements are being concluded on the rational use of ocean resources.
The Pacific Ocean is the largest ocean in terms of area and depth on Earth. Located between the continents of Eurasia and Australia in the west, North and South America in the east, Antarctica in the south.
- Area: 179.7 million km²
- Volume: 710.4 million km³
- Maximum depth: 10,994 m
- Average depth: 3984 m
The Pacific Ocean stretches approximately 15.8 thousand km from north to south and 19.5 thousand km from east to west. Square with seas
179.7 million km², average depth - 3984 m, water volume - 723.7 million km³ (excluding seas, respectively: 165.2 million km², 4282 m and 707.6 million km³). The greatest depth of the Pacific Ocean (and the entire World Ocean) is 10,994 m (in the Mariana Trench). The date line passes through the Pacific Ocean along the 180th meridian.
Etymology
The first European to see the ocean was the Spanish conquistador Balboa. In 1513, he and his companions crossed the Isthmus of Panama and came to the shore of an unknown ocean. Since they reached the ocean in a bay open to the south, Balboa called it the South Sea (Spanish Mar del Sur). On November 28, 1520, Fernand Magellan entered the open ocean. He crossed the ocean from Tierra del Fuego to the Philippine Islands in 3 months and 20 days. All this time the weather was calm, and Magellan called it the Pacific Ocean. In 1753, the French geographer Jean-Nicolas Buache proposed calling it the Great Ocean as the largest of the oceans. But this name did not receive universal recognition, and the name Pacific Ocean remains dominant in world geography. In English-speaking countries, the ocean is called English. Pacific Ocean.
Until 1917, the name Eastern Ocean was used on Russian maps, traditionally preserved from the time the Russian explorers reached the ocean.
Asteroid (224) Oceans is named after the Pacific Ocean.
Physical and geographical characteristics
General information
Occupying 49.5% of the World Ocean's surface and containing 53% of its water volume, the Pacific Ocean is the largest ocean on the planet. From east to west, the ocean stretches for more than 19 thousand km and 16 thousand - from north to south. Its waters are located mostly in the southern latitudes, less in the northern ones. 
In 1951, an English expedition aboard the Challenger research vessel recorded a maximum depth of 10,863 meters using an echo sounder. According to the results of measurements carried out in 1957 during the 25th voyage of the Soviet research vessel "Vityaz" (headed by Aleksey Dmitrievich Dobrovolsky), the maximum depth of the trough was 11,023 m (updated data, the depth was originally reported as 11,034 m). The difficulty in measuring is that the speed of sound in water depends on its properties, which are different at different depths, therefore, these properties must also be determined at several horizons with special instruments (such as a barometer and a thermometer), and in the depth value shown by the echo sounder , amended. Research in 1995 showed that it is about 10,920 m, and research in 2009 - that 10,971 m. The latest research in 2011 gives a value of 10,994 m with an accuracy of ± 40 m. Thus, the deepest point of the depression, called the Challenger Abyss "(Eng. Challenger Deep) is farther from sea level than Mount Chomolungma - above it.
With its eastern edge, the ocean washes the western coasts of North and South America, with its western edge it washes the eastern coasts of Australia and Eurasia, and from the south it washes Antarctica. The border with the Arctic Ocean is a line in the Bering Strait from Cape Dezhnev to Cape Prince of Wales. The border with the Atlantic Ocean is drawn from Cape Horn along the meridian 68 ° 04 'W. or along the shortest distance from South America to the Antarctic Peninsula through the Drake Passage, from Oste Island to Cape Sternek. The border with the Indian Ocean passes: south of Australia - along the eastern border of the Bass Strait to the island of Tasmania, then along the meridian 146 ° 55'E. d. to Antarctica; north of Australia - between the Andaman Sea and the Strait of Malacca, further along the southwestern coast of Sumatra, the Sunda Strait, the southern coast of Java, the southern borders of the Bali and Sawa Seas, the northern border of the Arafura Sea, the southwestern coast of New Guinea and the western border of the Torres Strait ... Sometimes the southern part of the ocean, with a northern boundary from 35 ° S. NS. (based on the circulation of water and atmosphere) up to 60 ° S. NS. (by the nature of the bottom relief), refer to Southern Ocean, which is not officially allocated.
Seas
The area of the seas, bays and straits of the Pacific Ocean is 31.64 million km² (18% of the total ocean area), the volume is 73.15 million km³ (10%). Most of the seas are located in the western part of the ocean along Eurasia: Bering, Okhotsk, Japanese, Inner Japanese, Yellow, East China, Philippine; seas between the islands of Southeast Asia: South China, Javan, Sulu, Sulawesi, Bali, Flores, Sava, Banda, Seram, Halmakhera, Molucca; along the coast of Australia: New Guinea, Solomonovo, Koralovoe, Fiji, Tasmanovo; Antarctica has seas (sometimes referred to as the Southern Ocean): D'Urville, Somov, Ross, Amundsen, Bellingshausen. There are no seas along North and South America, but there are large bays: Alaska, California, Panama. 
Islands
Several thousand islands scattered across the Pacific Ocean were formed by volcanic eruptions. Some of these islands overgrown with coral, and eventually the islands plunged into the sea again, leaving behind coral rings - atolls.
In terms of the number (about 10 thousand) and the total area of the islands, the Pacific Ocean ranks first among the oceans. In the ocean are the second and third largest islands of the Earth: New Guinea (829.3 thousand km²) and Kalimantan (735.7 thousand km²); the largest group of islands: the Great Sunda Islands (1485 thousand km², including the largest islands: Kalimantan, Sumatra, Sulawesi, Java, Banka). Other largest islands and archipelagos: New Guinea islands (New Guinea, Kolepom), Japanese islands(Honshu, Hokkaido, Kyushu, Shikoku), Philippine Islands (Luzon, Mindanao, Samar, Negros, Palawan, Panay, Mindoro), New Zealand (South and North Islands), Lesser Sunda Islands (Timor, Sumbawa, Flores, Sumba), Sakhalin, Moluccas (Seram, Halmahera), Bismarck Archipelago (New Britain, New Ireland), Solomon Islands (Bougainville), Aleutian Islands, Taiwan, Hainan, Vancouver, Fiji Islands (Viti Levu), Hawaiian Islands (Hawaii), New Caledonia, Kodiak Archipelago, Kuril Islands, New Hebrides, Queen Charlotte Islands, Galapagos Islands, Wellington, St. Lawrence, Ryukyu Islands, Riesco, Nunivak, Santa Ynez, D'Antrkasto Islands, Samoa Islands, Revipel Hijedomer, Archipelago, Archipelago Shantar Islands, Magdalena, Louisiada Archipelago, Linga Archipelago, Loyote Islands, Karaginsky, Clarence, Nelson, Princess Royal, Hanover, Commander Islands.
History of the formation of the ocean
With the disintegration of the Pangea continent in the Mesozoic era into Gondwana and Laurasia, the surrounding Panthalassa ocean began to decrease in area. By the end of the Mesozoic, Gondwana and Laurasia separated, and as their parts diverged, the modern Pacific Ocean began to form. Within the Pacific Basin, four fully oceanic tectonic plates developed during the Jurassic: Pacific, Kula, Farallon, and Phoenix. The northwestern Kula plate moved under the eastern and southeastern margins of the Asian continent. The northeastern oceanic plate Farallon moved under Alaska, Chukotka and under the western edge of North America. The southeastern Phoenix oceanic plate sank beneath the western edge of South America. In the Cretaceous, the southeastern Pacific Oceanic Plate moved under the eastern edge of the then united Australian-Antarctic continent, as a result of which blocks broke off from the mainland, which now form the New Zealand Plateau and the Lord Howe and Norfolk seamounts. In the Late Cretaceous, the split of the Austral-Antarctic continent began. The Australian plate broke off and began to move towards the equator. At the same time, in the Oligocene, the Pacific Plate changed its direction to the northwest. In the late Miocene, the Farallon plate split into two: Coconut and Nazca. The Kula Plate, moving to the northwest, completely sank (together with the northern edge of the Pacific Plate) under Eurasia and under the Proto-Aleutian trench. 
Today movement tectonic plates continues. The axis of this movement is the mid-oceanic rift zones in the South Pacific and East Pacific uplifts. To the west of this zone is the most large slab Pacific Ocean, which continues to move to the northwest at a speed of 6-10 cm per year, crawling under the Eurasian and Australian plates. In the west, the Pacific Plate is pushing the Philippine Plate northwestward under the Eurasian Plate at a rate of 6-8 cm per year. To the east of the mid-ocean rift zone are located: in the northeast, the Juan de Fuca plate, creeping at a speed of 2-3 cm per year under the North American plate; in the central part, the Cocos plate is pushed northeastward under the Caribbean lithospheric plate at a rate of 6-7 cm per year; to the south is the Nazca plate, moving eastward, sinking under the South American plate at a speed of 4-6 cm per year.
Geological structure and bottom topography
Submarine outskirts of continents
The underwater margins of the continents occupy 10% of the Pacific Ocean. The shelf relief shows the features of transgressive plains with subaerial relic relief. Such forms are typical for underwater river valleys on the Java shelf and for the shelf of the Bering Sea. On the Korean shelf and the shelf of the East China Sea, ridge relief forms formed by tidal currents are widespread. Various coral structures are widespread on the shelf of the equatorial-tropical waters. Most of the Antarctic shelf lies at depths of more than 200 m, the surface is very dissected, tectonic seamounts alternate with deep depressions - grabens. The continental slope of North America is heavily dissected by submarine canyons. Large underwater canyons are known on the continental slope of the Bering Sea. The continental slope of Antarctica is distinguished by the great width, diversity and dissection of the relief. Along North America, the continental foot is distinguished by very large cones of turbidity flows, merging into a single inclined plain, bordering a wide strip of the continental slope. 
The underwater outskirts of New Zealand has a peculiar continental structure. Its area is 10 times the area of the islands themselves. This submarine New Zealand plateau consists of the Campbell and Chatham flat-topped uplifts and the Bunkey depression between them. From all sides it is limited by the continental slope, bordered by the continental foot. This includes the Late Mesozoic submarine ridge Lord Howe.
Transition zone
On the western edge of the Pacific Ocean there are transition areas from the outskirts of the continents to the ocean floor: Aleutian, Kuril-Kamchatka, Japanese, East China, Indonesian-Philippine, Boninsko-Mariana (with the deepest point of the ocean - the Mariana Trench, depth 11,022 m), Melanesian, Vityazevskaya, Tonga-Kermadec, Macquarie. These transitional areas include deep trenches, marginal seas bounded by island arcs. On the eastern edge there are transitional areas: Central American and Peruvian-Chilean. They are expressed only by deep-sea trenches, and instead of island arcs, young rocky years of Central and South America stretch along the troughs.
All transitional areas are characterized by volcanism and high seismicity; they form the marginal Pacific belt of earthquakes and modern volcanism. The transitional regions on the western edge of the Pacific Ocean are located in the form of two echelons, the youngest regions in the developmental stage are located on the border with the ocean floor, and the more mature ones are separated from the ocean floor by island arcs and island land masses with a continental crust.
Mid-ocean ridges and ocean floor
11% of the Pacific Ocean floor area is occupied by mid-ocean ridges, represented by the South Pacific and East Pacific uplifts. They represent wide, weakly dissected hills. From the main system there are lateral branches in the form of the Chilean uplift and the Galapagos rift zone. The Pacific Ridge System also includes the Gorda, Juan de Fuca and Explorer Ranges in the northeast of the ocean. The mid-ocean ridges of the ocean are seismic belts with frequent surface earthquakes and intense volcanic activity. In the rift zone, fresh lavas and metalliferous sediments were found, usually associated with hydrothermal fluids. 
The system of Pacific uplifts divides the Pacific Ocean bed into two unequal parts. The eastern part is less complex and shallower. The Chilean uplift (rift zone) and the Nazca, Sala-i-Gomez, Carnegie and Cocos ridges are distinguished here. These ridges divide the eastern part of the bed into the Guatemalan, Panama, Peruvian and Chilean basins. All of them are characterized by intricately dissected hilly and mountainous bottom relief. In the area of the Galapagos Islands, a rift zone is distinguished.
Another part of the bed, lying to the west of the Pacific rises, occupies about 3/4 of the entire bed of the Pacific Ocean and has a very complex relief structure. Dozens of hills and underwater ridges divide the ocean floor into a large number of basins. The most significant ridges form a system of arcuate uplifts starting in the west and ending in the southeast. The first such arc is formed by the Hawaiian Ridge, parallel to it, the next arc is formed by the Cartographer Mountains, Markus Necker, the underwater ridge of the Line Islands, the arc ends with the underwater base of the Tuamotu Islands. The next arc consists of the underwater foundations of the Marshalov Islands, Kiribati, Tuvalu and Samoa. The fourth arc includes the Caroline Islands and the Kapingamarangi seamount. The fifth arc consists of the southern group of the Caroline Islands and the Eauripik rampart. Some ridges and hills differ in their strike from those listed above, these are the Imperial (North-Western) ridge, the Shatsky, Magellan, Hessa, Manihiki uplands. These uplands are distinguished by leveled summit surfaces and are covered from above with carbonate deposits of increased thickness.
The Hawaiian Islands and the Samoa archipelago have active volcanoes. About 10 thousand separate seamounts, mostly of volcanic origin, are scattered over the Pacific Ocean floor. Many of them are guyots. The tops of some guyots are at a depth of 2-2.5 thousand meters, the average depth above them is about 1.3 thousand meters. The vast majority of the islands in the central and western parts of the Pacific Ocean are of coral origin. Almost all volcanic islands are bordered by coral structures.
For the bed and the mid-oceanic ridges of the Pacific Ocean, fault zones are characteristic, usually expressed in the relief in the form of complexes of consistently and linearly oriented grabens and horsts. All fault zones have their own names: Surveyor, Mendocino, Murray, Clarion, Clipperton and others. The depressions and uplifts of the Pacific Ocean floor are characterized by an oceanic crust, with a sedimentary layer thickness from 1 km in the northeast to 3 km on the Shatsky Upland and with a basalt layer thickness from 5 km to 13 km. The mid-oceanic ridges have a riftogenic crust, which is characterized by increased density. Ultrabasic rocks are found here, and crystalline shales were raised in the Eltanin fault zone. Subcontinental (Kuril Islands) and continental crust (Japanese Islands) were found under the island arcs.
Bottom sediments
Major rivers of Asia, such as the Amur, Yellow He, Yangtze, Mekong and others, carry more than 1,767 million tons of sediment into the Pacific Ocean per year. This alluvium almost completely remains in the water area of the marginal seas and bays. The largest rivers in America - Yukon, Colorado, Columbia, Fraser, Guayas and others - give about 380 million tons of sediment per year, and 70-80% of suspended material is carried into the open ocean, which is facilitated by the small width of the shelf. 
Red clays are widespread in the Pacific Ocean, especially in the northern hemisphere. This is due to the great depth of the ocean basins. In the Pacific Ocean, there are two belts (southern and northern) of siliceous diatomaceous oozes, as well as a well-defined equatorial belt of siliceous radiolarian deposits. Vast areas of the bottom of the southwest of the ocean are occupied by coral-algal biogenic deposits. Foraminiferal silts are widespread to the south of the equator. There are several fields of pteropod deposits in the Coral Sea. In the northern deepest part of the Pacific Ocean, as well as in the South and Peruvian basins, extensive fields of ferromanganese nodules are observed.
Climate
The climate of the Pacific Ocean is formed due to the zonal distribution of solar radiation and atmospheric circulation, as well as a powerful seasonal influence Asian mainland. Almost all climatic zones can be distinguished in the ocean. In the northern temperate zone in winter, the Aleutian pressure minimum is the baric center, which is weakly expressed in summer. To the south is the North Pacific Anticyclone. Equatorial depression is noted along the equator (area reduced pressure), which is replaced to the south by the South Pacific anticyclone. Further south, the pressure decreases again and then again gives way to a high pressure area over Antarctica. The wind direction is formed in accordance with the location of the pressure centers. In the temperate latitudes of the northern hemisphere, strong westerly winds prevail in winter, and weak southerly in summer. In the northwest of the ocean, in winter, northerly and northeastern monsoon winds are established, which in summer are replaced by southern monsoons. Cyclones occurring at polar fronts determine the high frequency of storm winds in the temperate and circumpolar zones (especially in the southern hemisphere). In the subtropics and tropics of the northern hemisphere, the northeastern trade winds dominate. In the equatorial zone, mostly calm weather is observed throughout the year. In the tropical and subtropical zones of the southern hemisphere, a stable southeastern trade wind dominates, strong in winter and weak in summer. In the tropics, violent tropical hurricanes, here called typhoons, arise (mainly in summer). They usually arise east of the Philippines, from where they move to the northwest and north through Taiwan, Japan and fade out on the approaches to the Bering Sea. Another area of origin of typhoons is the coastal regions of the Pacific Ocean adjacent to Central America. In the forties latitudes of the southern hemisphere strong and constant westerly winds are observed. In the high latitudes of the southern hemisphere, the winds are subject to the general cyclonic circulation characteristic of the low-pressure Antarctic region. 
The distribution of air temperature over the ocean is subordinated to the general latitudinal zoning, but the western part has a warmer climate than the eastern one. In tropical and equatorial zones, average air temperatures prevail from 27.5 ° C to 25.5 ° C. In summer, the 25 ° C isotherm expands northward in the western part of the ocean and only slightly in the eastern, and shifts strongly northward in the southern hemisphere. Passing over the vast expanses of the ocean, the air masses are intensely saturated with moisture. On both sides of the equator, in the equatorial zone, there are two narrow bands of maximum precipitation, outlined by an isohyet of 2000 mm, and a relatively dry zone is expressed along the equator. In the Pacific Ocean there is no zone of convergence of the northern trade winds with the southern ones. There are two independent zones with excessive moisture and a relatively dry zone separating them. To the east, in the equatorial and tropical zones, the amount of precipitation decreases. The driest areas in the northern hemisphere are adjacent to California, in the southern - to the Peruvian and Chilean basins (coastal areas receive less than 50 mm of rainfall per year).
Hydrological regime
Surface water circulation
The general scheme of the currents of the Pacific Ocean is determined by the regularities of the general circulation of the atmosphere. The northeastern trade wind of the northern hemisphere contributes to the emergence of the NW trade wind, which crosses the ocean from the Central American coast to the Philippine Islands. Further, the current is divided into two branches: one deviates to the south and partly feeds the Equatorial countercurrent, and partly spreads over the basins of the Indonesian seas. The northern arm enters the East China Sea and, leaving it south of Kyushu Island, gives rise to a powerful warm current Kuroshio. This current follows northward to the Japanese coast, having a noticeable effect on the climate of the Japanese coast. At 40 ° N. NS. Kuroshio passes into the North Pacific Current, following eastward to the Oregon coast. Colliding with North America, it divides into the northern branch of the warm Alaskan Current (passing along the mainland to the Alaska Peninsula) and the southern branch of the cold California Current (along the California Peninsula, flowing into the North-Trade Current, closing the circle). In the southern hemisphere, the Southeast Tradewind forms the South Tradewind Current, which traverses the Pacific Ocean from the shores of Colombia to the Moluccas. Between the Line Islands and the Tuamotu it forms an offshoot, following into the Coral Sea and further south along the coast of Australia, forming the East Australian Current. The main masses of the South Tradewind Current east of the Moluccas merge with the southern branch of the North Tradewind Current and together form the Equatorial Countercurrent. The East Australian Current south of New Zealand joins the powerful Antarctic Circumpolar Current from the Indian Ocean, crossing the Pacific Ocean from west to east. At the southern end of South America, this current branches off to the north in the form of the Peruvian Current, which in the tropics flows into the South Tradewind Current, closing the southern circle of currents. Another branch of the current of the Western Winds bends around South America, called the Cape Horn Current, and goes into the Atlantic Ocean. An important role in the circulation of the waters of the Pacific Ocean belongs to the cold subsurface Cromwell Current, flowing under the South Passat Current from 154 ° W. to the area of the Galapagos Islands. El Niño is observed in the summer in the eastern equatorial part of the ocean, when a warm, slightly saline current pushes the cold Peruvian current off the coast of South America. At the same time, the supply of oxygen to the subsurface layers stops, which leads to the death of plankton, fish and birds that feed on them, and heavy rains fall on the usually arid coast, causing catastrophic floods. 
Salinity, ice formation
The tropical zones have the maximum salinity (maximum up to 35.5-35.6 ‰), where the intensity of evaporation is combined with a relatively small amount of precipitation. To the east, under the influence of cold currents, salinity decreases. Large amounts of precipitation also reduce salinity, especially at the equator and in the western circulation zones of temperate and subpolar latitudes.
Ice in the south of the Pacific Ocean is formed in the Antarctic regions, and in the north - only in the Bering, Okhotsk and partly in the Sea of Japan. A certain amount of ice is dumped from the shores of southern Alaska in the form of icebergs, which reach 48-42 ° N in March-April. NS. The North Seas, especially the Bering Sea, supply almost the entire mass of floating ice in the northern regions of the ocean. In Antarctic waters, the boundary of pack ice reaches 60-63 ° S. sh., icebergs spread far to the north, up to 45 ° N. NS.
Water masses
In the Pacific Ocean, surface, subsurface, intermediate, deep and bottom water masses are distinguished. The surface water mass has a thickness of 35-100 m and is distinguished by the relative evenness of temperatures, salinity and density, which is especially characteristic of tropical waters, variability of characteristics due to the seasonality of climatic phenomena. This water mass is determined by heat exchange at the ocean surface, the ratio of precipitation and evaporation, and intense mixing. The same, but to a lesser extent, applies to subsurface water masses. In the subtropics and cold latitudes, these water masses are surface for half a year, and for half a year they turn out to be subsurface. In different climatic zones their boundary with intermediate waters ranges between 220 and 600 m. Subsurface waters are characterized by increased salinity and density, at temperatures ranging from 13-18 ° C (in the tropics and subtropics) to 6-13 ° C (in the temperate zone). Subsurface waters in warmer climates are formed by lowering saltier surface waters. 
Intermediate water masses of temperate and high latitudes have a temperature of 3-5 ° C and a salinity of 33.8-34.7 ‰. The lower boundary of the intermediate masses is located at a depth of 900 to 1700 m. Deep water masses are formed as a result of the immersion of cooled waters in Antarctic waters and the waters of the Bering Sea and their subsequent spreading over the basins. Bottom water masses are located at depths of more than 2500-3000 m. They are characterized by low temperatures (1-2 ° C) and uniformity of salinity (34.6-34.7 ‰). These waters form on the Antarctic shelf under strong cooling conditions. Gradually, they spread along the bottom, fill all the depressions and penetrate through the transverse passages in the mid-oceanic ridges into the South and Peruvian, and then into the northern basins. Compared to the bottom waters of other oceans and the southern part of the Pacific Ocean, the bottom water masses of the northern basins of the Pacific Ocean are characterized by a reduced content of dissolved oxygen. Bottom waters, together with deep waters, make up 75% of the total volume of the Pacific Ocean.
Flora and fauna
The Pacific Ocean accounts for more than 50% of the total biomass of the World Ocean. Life in the ocean is abundant and varied, especially in the tropical and subtropical zones between the coasts of Asia and Australia, where vast areas are occupied by coral reefs and mangroves. The phytoplankton of the Pacific Ocean is mainly composed of microscopic unicellular algae, numbering about 1300 species. About half of the species belong to peridineas and slightly less to diatoms. Most of the vegetation is concentrated in shallow water areas and in upwelling zones. The bottom vegetation of the Pacific Ocean numbers about 4 thousand species of algae and up to 29 species of flowering plants. In the temperate and cold regions of the Pacific Ocean, brown algae are massively widespread, especially from the kelp group, and in the southern hemisphere there are giants from this family up to 200 m long.In the tropics, fucus, large green and famous red algae are especially common, which, along with coral polyps, are reef-forming organisms. 
The fauna of the Pacific Ocean is 3-4 times richer in species composition than in other oceans, especially in tropical waters. In the Indonesian seas, more than 2 thousand species of fish are known, in the northern seas there are only about 300. In the tropical zone of the ocean there are more than 6 thousand species of mollusks, and in the Bering Sea there are about 200. For the fauna of the Pacific Ocean, characteristic features are the antiquity of many taxonomic groups and endemism. A large number of ancient species of sea urchins, primitive genera of horseshoe crabs, some very ancient fish that have not survived in other oceans (for example, Jordan, Gilbertidia) live here; 95% of all salmon species live in the Pacific Ocean. Endemic species of mammals: dugong, fur seal, sea lion, sea otter. For many species of the Pacific Ocean fauna, gigantism is characteristic. In the northern part of the ocean, giant mussels and oysters are known; in the equatorial zone, the largest bivalve mollusk, tridacna, lives, weighing up to 300 kg. The ultraabyssal fauna is most clearly represented in the Pacific Ocean. Under conditions of tremendous pressure, low water temperature at a depth of more than 8.5 km, about 45 species live, of which more than 70% are endemic. Among these species, sea cucumbers predominate, leading a very sedentary lifestyle and able to pass through the gastrointestinal tract great amount soil, the only source of food at these depths. 
Ecological problems
Human economic activity in the Pacific Ocean has led to the pollution of its waters, to the depletion of biological resources. So, by the end of the 18th century, sea cows in the Bering Sea were completely exterminated. At the beginning of the 20th century, northern fur seals and some species of whales were on the verge of extinction; now their fishing is limited. A great danger in the ocean is the pollution of waters with oil and oil products (the main pollutants), some heavy metals and wastes from the nuclear industry. Harmful substances are carried by currents throughout the ocean. Even off the coast of Antarctica, these substances were found in the composition of marine organisms. Ten US states routinely dump their waste into the sea. In 1980, more than 160,000 tons of waste was destroyed in this way, since then this figure has decreased. 
In the North Pacific Ocean, the Great Pacific Garbage Patch of plastic and other waste was formed, formed by ocean currents, gradually concentrating debris thrown into the ocean in one area thanks to the North Pacific Currents System. This patch stretches across the North Pacific Ocean from a point about 500 nautical miles off the California coast, past Hawaii, and nearly reaches Japan. In 2001, the mass of the garbage island was more than 3.5 million tons, and the area was more than 1 million km², which was six times the mass of zooplankton. Every 10 years, the landfill area increases by an order of magnitude.
On August 6 and 9, 1945, the US Armed Forces carried out the atomic bombings of the Japanese cities of Hiroshima and Nagasaki - the only two examples of the military use of nuclear weapons in the history of mankind. The total death toll ranged from 90 to 166 thousand people in Hiroshima and from 60 to 80 thousand people in Nagasaki. From 1946 to 1958, the United States of America conducted nuclear tests on the Bikini and Enewetok Atolls (Marshall Islands). A total of 67 explosions of atomic and hydrogen bombs were made. On March 1, 1954, during a surface test of a hydrogen bomb with a capacity of 15 megatons, the explosion produced a crater 2 km in diameter and 75 m deep, a mushroom cloud 15 km high and 20 km in diameter. As a result, Bikini Atoll was destroyed, and the territory was exposed to the largest radioactive contamination and exposure of local residents in the history of the United States. In 1957-1958, Great Britain carried out 9 atmospheric nuclear tests at the Christmas and Malden Atolls (Line Islands) in Polynesia. In 1966-1996, France carried out 193 nuclear tests (including 46 in the atmosphere, 147 underground) on the atolls of Mururoa and Fangataufa (Tuamotu archipelago) in French Polynesia. 
On March 23, 1989, off the coast of Alaska, the Exxon Valdez tanker, owned by ExxonMobil (USA), crashed. As a result of the disaster, about 260 thousand barrels of oil spilled into the sea, forming a slick of 28 thousand km². About two thousand kilometers of the coastline was polluted with oil. This accident was considered the largest environmental disaster ever to occur at sea (up until the DH rig accident in the Gulf of Mexico on April 20, 2010).
Pacific Coast States
States along the borders of the Pacific Ocean (clockwise):
- USA,
- Canada,
- United Mexican States,
- Guatemala,
- El Salvador,
- Honduras,
- Nicaragua,
- Costa Rica,
- Panama,
- Colombia,
- Ecuador,
- Peru,
- Chile,
- Australian Union,
- Indonesia,
- Malaysia,
- Singapore,
- Brunei Darussalam,
- Philippines,
- Thailand,
- Cambodia,
- Socialist Republic of Vietnam,
- People's Republic of China,
- The Republic of Korea,
- Democratic People's Republic of Korea,
- Japan,
- Russian Federation.
Directly in the oceanic expanses, there are island states and possessions of states that are not part of the region, forming Oceania:
Melanesia:
- Vanuatu,
- New Caledonia (France),
- Papua New Guinea,
- Solomon islands,
- Fiji;
Micronesia:
- Guam (USA),
- Kiribati,
- Marshall Islands,
- Nauru,
- Palau,
- Northern Mariana Islands (USA),
- Wake Atoll (USA),
- Federated States of Micronesia;
Polynesia:
- Eastern Samoa (USA),
- New Zealand,
- Samoa,
- Tonga,
- Tuvalu,
- Pitcairn (UK),
- Wallis and Futuna (France),
- French Polynesia (France).
History of Pacific exploration
The study and development of the Pacific Ocean began long before the written history of mankind appeared. For sailing on the ocean, junks, catamarans and simple rafts were used. The 1947 expedition on the Kon-Tiki balsa log raft led by the Norwegian Thor Heyerdahl proved the possibility of crossing the Pacific Ocean westward from central South America to the Polynesian islands. Chinese junks made treks along the shores of the ocean to the Indian Ocean (for example, the seven voyages of Zheng He in 1405-1433). 
The first European to see the Pacific Ocean was the Spanish conquistador Vasco Nunez de Balboa, who in 1513, from one of the peaks of a mountain range on the Isthmus of Panama, "in silence" saw the boundless water surface of the Pacific Ocean spreading to the south and christened it the South Sea. In the fall of 1520, the Portuguese navigator Fernand Magellan circled South America, crossing the strait, after which he saw new expanses of water. During the further transition from Tierra del Fuego to the Philippine Islands, which took more than three months, the expedition did not encounter a single storm, which is obviously why Magellan called the ocean Pacific. The first detailed map of the Pacific Ocean was published by Ortelius in 1589. As a result of the expedition of 1642-1644 under the command of Tasman, it was proved that Australia is a separate continent.
Active exploration of the ocean began in the 18th century. The leading states of Europe began to send scientific research expeditions to the Pacific Ocean, led by navigators: the Englishman James Cook (exploration of Australia and New Zealand, the discovery of many islands, including Hawaii), the French Louis Antoine Bougainville (exploration of the islands of Oceania) and Jean-Francois La Perouse , Italian Alessandro Malaspina (mapped the entire western coast of South and North America from Cape Horn to the Gulf of Alaska). The northern part of the ocean was explored by Russian explorers S.I.Dezhnev (discovery of the strait between Eurasia and North America), V. Bering (exploration of the northern shores of the ocean) and A.I. north-east coast of Asia). During the period from 1803 to 1864, Russian sailors made 45 round-the-world and semicircular voyages, as a result of which the Russian military and commercial fleet mastered the sea route from Baltic Sea to the Pacific Ocean and along the way discovered several islands in the ocean. During a round-the-world expedition of 1819-1821 under the leadership of F.F.Bellingshausen and M.P. Lazarev, Antarctica and, incidentally, 29 islands of the Southern Ocean were discovered.
From 1872 to 1876, the first scientific oceanic expedition took place on the English sailing-steam corvette "Challenger", new data were obtained on the composition of ocean waters, on flora and fauna, on the bottom topography and soils, the first map of the ocean depths was compiled and the first collection was collected deep-sea animals. A round-the-world expedition on the Russian sailing-propeller corvette "Vityaz" in 1886-1889 under the leadership of the oceanographer S.O. Makarov explored the northern part of the Pacific Ocean in detail. Makarov carefully studied the results of this expedition and all previous Russian and foreign expeditions, many round-the-world travels and for the first time made a conclusion about the circular rotation and counterclockwise direction of surface currents in the Pacific Ocean. The result of the American expedition of 1883-1905 on board the Albatross ship was the discovery of new species of living organisms and the patterns of their development. A great contribution to the exploration of the Pacific Ocean was made by the German expedition on board the Planet (1906-1907) and the American oceanographic expedition on the non-magnetic schooner Carnegie (1928-1929) under the leadership of the Norwegian H. W. Sverdrup. In 1949, a new Soviet research vessel "Vityaz" was launched under the flag of the USSR Academy of Sciences. Until 1979, the ship made 65 scientific voyages, as a result of which many "white spots" on the maps of the underwater relief of the Pacific Ocean were closed (in particular, the maximum depth in the Mariana Trench was measured). At the same time, research was conducted by the expeditions of Great Britain - Challenger II (1950-1952), Sweden - Albatross III (1947-1948), Denmark - Galatea (1950-1952) and many others, which brought a lot of new information about topography of the ocean floor, bottom sediments, life in the ocean, physical characteristics of its waters. In the framework of the International Geophysical Year (1957-1958), international forces (especially the USA and the USSR) carried out studies, as a result of which new bathymetric and marine navigational charts of the Pacific Ocean were compiled. Since 1968, the American ship "Glomar Challenger" has carried out regular deep-water drilling, work on the movement of water masses at great depths, and biological research. On January 23, 1960, the first man plunged into the bottom of the deepest depression in the World Ocean - the Mariana. US Navy Lieutenant Don Walsh and researcher Jacques Piccard landed there in the Trieste research submersible. On March 26, 2012, American director James Cameron, aboard the Deepsea Challenger, made the first solo and second ever dive to the bottom of the Mariana Trench. The device stayed at the bottom of the depression for about six hours, during which samples of underwater soil, plants and living organisms were collected. The footage shot by Cameron will form the basis of the National Geographic TV documentary.
In 1966-1974 the monograph "The Pacific Ocean" in 13 volumes was published by the Institute of Oceanography of the Academy of Sciences of the USSR. In 1973, the Pacific Oceanological Institute named after V.I. VI Ilyichev, whose efforts were carried out extensive studies of the Far Eastern seas and the open space of the Pacific Ocean. In recent decades, numerous measurements of the ocean from space satellites have been carried out. The result was a bathymetric atlas of the oceans, released in 1994 by the American National Geophysical Data Center, with a map resolution of 3-4 km and a depth accuracy of ± 100 m.
Economic significance
Currently, the coast and islands of the Pacific Ocean are developed and populated extremely unevenly. The largest centers of industrial development are the US coast (from the Los Angeles area to the San Francisco area), the coast of Japan and South Korea. The ocean plays a significant role in the economic life of Australia and New Zealand. The South Pacific is a graveyard for spaceships. Here, far from shipping routes, decommissioned space objects are flooded. 
Fishing and marine industries
The temperate and tropical latitudes of the Pacific Ocean are of the greatest commercial value. The Pacific Ocean accounts for about 60% of the world's fish catch. Among them are salmon (pink salmon, chum salmon, coho salmon, sima), herring (anchovies, herring, sardines), cod (cod, pollock), perch (mackerel, tuna), flounder (flounder). Mammals are being hunted: sperm whale, minke whales, fur seal, sea otter, walrus, sea lion; invertebrates: crabs, shrimps, oysters, scallops, cephalopods. A number of plants (kelp (seaweed), anfelcia (agaronos), seagrass and phyllospadix) are harvested and processed into Food Industry and for medicine. The most productive fishery is carried out in the West-Central and North-West Pacific Ocean. The largest fishing powers of the Pacific Ocean: Japan (Tokyo, Nagasaki, Shimonoseki), China (Zhoushan archipelago, Yantai, Qingdao, Dalian), Russian Federation (Primorye, Sakhalin, Kamchatka), Peru, Thailand, Indonesia, Philippines, Chile, Vietnam, South Korea, DPRK, Australia, New Zealand, USA.
Transport routes
Important sea and air communications between the countries of the Pacific basin and transit routes between the countries of the Atlantic and Indian oceans run through the Pacific Ocean. Major ocean routes lead from Canada and the United States to Taiwan, China and the Philippines. The main shipping straits of the Pacific Ocean: Bering, Tatarsky, La Perouse, Korean, Taiwan, Singapore, Malacca, Sangarsky, Bassov, Torres, Cook, Magellan. The Pacific Ocean is connected to the Atlantic Ocean by the artificial Panama Canal, dug between North and South America along the Isthmus of Panama. Major ports: Vladivostok (general cargo, oil products, fish and seafood, timber and lumber, scrap metal, ferrous and non-ferrous metals), Nakhodka (coal, oil products, containers, metal, scrap metal, refrigerated cargo), Vostochny, Vanino (coal, oil) ( Russia), Busan (Republic of Korea), Kobe-Osaka (oil and oil products, machinery and equipment, cars, metals and scrap metal), Tokyo-Yokohama (scrap metal, coal, cotton, grain, oil and oil products, rubber, chemicals, wool, machinery and equipment, textiles, automobiles, medicines), Nagoya (Japan), Tianjin, Qingdao, Ningbo, Shanghai (all types of dry, liquid and general cargo), Xianggang (textiles, clothing, fiber, radio and electrical goods, plastic products, machinery, equipment), Kaohsiung, Shenzhen, Guangzhou (China), Ho Chi Minh City (Vietnam), Singapore (petroleum products, rubber, food, textiles, machinery and equipment) (Singapore), Klang (Malaysia), Jakarta (Indonesia), Manila (Philippines ), Sydney (general cargo, iron ore, coal, not ferry and oil products, grain), Newcastle, Melbourne (Australia), Auckland (New Zealand), Vancouver (timber cargo, coal, ores, oil and oil products, chemical and general cargo) (Canada), San Francisco, Los Angeles ( oil and oil products, copra, chemical cargo, timber, grain, flour, canned meat and fish, citrus fruits, bananas, coffee, machinery and equipment, jute, cellulose), Oakland, Long Beach (USA), Colon (Panama), Huasco (ores, fish, fuel, food) (Chile). The Pacific Basin has a significant number of relatively small multifunctional ports. 
Air transportation across the Pacific Ocean plays an important role. The first regular flight across the ocean was made in 1936 on the route San Francisco (USA) - Honolulu (Hawaii) - Manila (Philippines). Currently, the main transoceanic routes are laid through the North and Central Pacific. Airways are of great importance in domestic traffic and between islands. In 1902, Great Britain laid the first underwater telegraph cable (length 12.55 thousand km) across the ocean floor, passing through the Fanning Islands and Fiji, connecting Canada, New Zealand, and the Australian Union. Radio communication has been widely and for a long time used. Today, artificial earth satellites are used for communication across the Pacific Ocean, which significantly expands the capacity of communication channels between countries.
Minerals
The Pacific Ocean floor hides rich deposits of various minerals. Oil and gas are produced on the shelves of China, Indonesia, Japan, Malaysia, the United States of America (Alaska), Ecuador (Guayaquil Gulf), Australia (Bass Strait) and New Zealand. According to existing estimates, the bowels of the Pacific Ocean contain up to 30-40% of all potential oil and gas reserves of the World Ocean. The largest producer of tin concentrates in the world is Malaysia, and Australia is the largest producer of zircon, ilmenite and others. The ocean is rich in ferromanganese nodules, with total reserves on the surface of up to 7 1012 tons. The most extensive reserves are observed in the northern deepest part of the Pacific Ocean, as well as in the South and Peruvian basins. In terms of the main ore elements, ocean nodules contain 7.1 1010 tons of manganese, 2.3 109 tons of nickel, 1.5 109 tons of copper, 1 109 tons of cobalt. Kuril ridge and Sakhalin shelf in the Sea of Okhotsk, the Nankai trench in the Sea of Japan and around the coast of Japan, in the Peruvian depression. In 2013, Japan intends to begin pilot drilling to extract natural gas from methane hydrate fields at the bottom of the Pacific Ocean northeast of Tokyo.
Recreational resources
The recreational resources of the Pacific are highly diverse. According to the World Tourism Organization, at the end of the 20th century, East Asia and the Pacific accounted for 16% of international tourist visits (by 2020, the share is projected to increase to 25%). The main countries of formation of outbound tourism in this region are Japan, China, Australia, Singapore, Republic of Korea, Russia, USA and Canada. The main recreational areas: Hawaii, Polynesia and Micronesia, the east coast of Australia, Bohai Bay and Hainan Island in China, the coast of the Sea of Japan, areas of cities and urban agglomerations of the coast of North and South America. 
Among the countries with the largest flow of tourists (as of 2010 by the World Tourism Organization) in the Asia-Pacific region stand out: China (55 million visits per year), Malaysia (24 million), Hong Kong (20 million), Thailand (16 million), Macau (12 million), Singapore (9 million), Republic of Korea (9 million), Japan (9 million), Indonesia (7 million), Australia (6 million), Taiwan (6 million), Vietnam (5 million), Philippines (4 million), New Zealand (3 million), Cambodia (2 million), Guam (1 million); in coastal countries of the Americas: USA (60 million), Mexico (22 million), Canada (16 million), Chile (3 million), Colombia (2 million), Costa Rica (2 million), Peru (2 million ), Panama (1 million), Guatemala (1 million), El Salvador (1 million), Ecuador (1 million).
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