The Pacific (or Great) Ocean occupies 1/3 of the Earth's surface and almost half the area and more than half the volume of the World Ocean. It is the largest, warmest (in terms of surface water temperature) and deepest of all oceans. The ocean is located in all hemispheres of the Earth and is surrounded by Eurasia and Australia in the west, North and South America in the east and Antarctica in the south. Its border with the Arctic Ocean runs along the Bering Strait, with the Atlantic Ocean - along the narrowest point of the Drake Passage, and with the Indian Ocean - along a conventional line (the Pacific Ocean includes all seas between the islands of the Malay Archipelago, and to the south of Australia - all waters east of the 145th meridian E.D.)
The coastline is relatively straight off the coasts of North and South America and highly dissected off the coast of Eurasia. Fjord and abrasion types of shores predominate. In tropical latitudes in the west, the shores are coral, sometimes with barrier reefs. The shores of Antarctica are formed by ice shelves. In the western part of the ocean there are many archipelagos and individual islands - in terms of their number and area, the Pacific Ocean ranks 1st. Most of the marginal seas are located here.
The relief of the bottom of the Pacific Ocean is very complex. The shelf is relatively narrow, especially off the coast of North and South America (several tens of kilometers), and off the coast of Eurasia it measures hundreds of kilometers. In the peripheral parts of the ocean there are deep-sea trenches (25 of the 35 trenches in the World Ocean with a depth of more than 5 km and all four trenches with a depth of more than 10 km). Large uplifts, individual mountains and ridges divide the ocean floor into basins. In the southeast is the East Pacific Rise, which is part of the system of mid-ocean ridges.
Most of the ocean lies on one lithospheric plate. Deep-sea trenches and island arcs are confined to the zones of its interaction with continental plates, the “Pacific Ring of Fire” (a chain of active volcanoes and the epicenters of land and underwater earthquakes that cause tsunamis), as well as deposits of ore minerals, are associated with them.
Mineral resources. Large reserves of ferromanganese nodules are concentrated on the ocean floor. Oil and gas deposits have been discovered on the shelves off the coast of Asia and South America. Placer deposits of gold and tin were found in loose sediments near the shores. Phosphorite deposits are confined to the zones of rising deep waters off the western tropical coast of South America.
Climate. Most of the Pacific Ocean lies in the equatorial, subequatorial and tropical zones. Here the air temperature is +16...+24 °C all year round. In the north of the ocean in winter it drops below 0 °C; off the coast of Antarctica this temperature remains constant. Trade winds dominate in tropical latitudes, westerly winds dominate in temperate latitudes, and monsoons dominate off the coast of Eurasia. There are often severe storms and typhoons. The maximum amount of precipitation (about 3000 mm) falls in the western part of the equatorial belt, the minimum in the eastern regions between the equator and the southern tropic (about 100 mm).
Near Antarctica, sea ice lasts all year. In the northern part - only in winter. Antarctic icebergs are observed up to 40° south. w.
Currents. There are two huge rings of water movement in the ocean. The Northern Ring includes the North Trade Wind, Kuroshio, North Pacific and California Currents; Southern - South Trade Wind, East Australian Current, West Wind Current and Peruvian Current. They have a significant impact on the redistribution of heat in the ocean and on the nature of the adjacent land. For example, trade wind currents transport warm water from the eastern parts of the ocean to the western ones, so at low latitudes the western part of the ocean is significantly warmer than the eastern part. In the middle and high latitudes, on the contrary, the eastern parts of the ocean are warmer than the western ones.
Organic world. In terms of the number of species and biomass, the organic world of the Pacific Ocean is richer than in other oceans (fauna has about 100 thousand species, and phytoplankton - 380). Organic life is especially rich in equatorial-tropical latitudes, in areas of coral reefs. The northern part of the ocean is characterized by various species of salmon fish. Ocean fishing accounts for almost half of the world's production. Main commercial species: salmon, cod, flounder, perch. The main fishing areas are upwelling areas off the coast of America (the waters off the coast of South America are especially productive between 4 and 23° S), areas of interaction between warm and cold waters, and western shelves.
Natural complexes. The Pacific Ocean has all natural zones, except the northern polar one; they are elongated in the latitudinal direction.
In the Northern subpolar zone there is intense water circulation, so they are rich in fish. The northern temperate zone is characterized by the interaction of warm and cold water masses. The oxygen-rich waters are full of a variety of organisms.
The western part of the Northern subtropical zone is warm, the eastern part is cold. The waters are poorly mixed, and the number of plankton and fish is small.
In the Northern tropical zone there are many isolated islands and archipelagos and the Northern Trade Wind Current is formed. Water productivity is low. In the equatorial belt, there is a complex interaction of various currents, at the boundaries of which ascending currents are formed and biological productivity increases. The shelves of the Sunda Islands and aquatic complexes of coral reefs are the richest in life.
The natural zones of the Southern Hemisphere are similar to the northern ones, but differ in the composition of organisms.
Our Earth appears to be a blue planet from space. This is because ¾ of the surface of the globe is occupied by the World Ocean. He is united, although greatly divided.
The surface area of the entire World Ocean is 361 million square meters. km.
Oceans of our planet
The ocean is the water shell of the earth, the most important component of the hydrosphere. Continents divide the World Ocean into parts.
Currently, it is customary to distinguish five oceans:
. - the largest and oldest on our planet. Its surface area is 178.6 million square meters. km. It occupies 1/3 of the Earth and makes up almost half of the World Ocean. To imagine this magnitude, it is enough to say that the Pacific Ocean can easily accommodate all the continents and islands combined. This is probably why it is often called the Great Ocean.
The Pacific Ocean owes its name to F. Magellan, who crossed the ocean under favorable conditions during his trip around the world.
The ocean has an oval shape, its widest part is located near the equator.
The southern part of the ocean is an area of calm, light winds and a stable atmosphere. To the west of the Tuamotu Islands, the picture changes dramatically - here is an area of storms and squalls that turn into fierce hurricanes.
In the tropical region, the waters of the Pacific Ocean are clean, transparent and have a deep blue color. A favorable climate developed near the equator. The air temperature here is +25ºC and practically does not change throughout the year. Winds are moderate and often calm.
The northern part of the ocean is similar to the southern part, as if in a mirror image: in the west there is unstable weather with frequent storms and typhoons, in the east there is peace and quiet.
The Pacific Ocean is the richest in the number of animal and plant species. Its waters are home to over 100 thousand species of animals. Almost half of the world's fish catch is caught here. The most important sea routes are laid through this ocean, connecting 4 continents at once.
. occupies an area of 92 million square meters. km. This ocean, like a huge strait, connects the two poles of our planet. The Mid-Atlantic Ridge, famous for the instability of the earth's crust, runs through the center of the ocean. Individual peaks of this ridge rise above the water and form islands, the largest of which is Iceland.
The southern part of the ocean is influenced by trade winds. There are no cyclones here, so the water here is calm, clean and clear. Closer to the equator, the Atlantic changes completely. The waters here are muddy, especially along the coast. This is explained by the fact that large rivers flow into the ocean in this part.
The northern tropical zone of the Atlantic is famous for its hurricanes. Two major currents meet here - the warm Gulf Stream and the cold Labrador Stream.
The northern latitudes of the Atlantic are the most picturesque area with huge icebergs and powerful ice tongues protruding from the waters. This area of the ocean is dangerous for shipping.
. (76 million sq. km) is an area of ancient civilizations. Navigation began to develop here much earlier than in other oceans. The average depth of the ocean is 3700 meters. The coastline is slightly indented, with the exception of the northern part, where most of the seas and bays are located.
The waters of the Indian Ocean are saltier than others because there are far fewer rivers flowing into it. But thanks to this, they are famous for their amazing transparency and rich azure and blue color.
The northern part of the ocean is a monsoon region; typhoons often form in autumn and spring. Closer to the south, the water temperature is lower, due to the influence of Antarctica.
. (15 million sq. km) is located in the Arctic and occupies vast areas around the North Pole. Maximum depth - 5527m.
The central part of the bottom is a continuous intersection of mountain ranges, between which there is a huge basin. The coastline is heavily dissected by seas and bays, and in terms of the number of islands and archipelagos, the Arctic Ocean ranks second after such a giant as the Pacific Ocean.
The most characteristic part of this ocean is the presence of ice. The Arctic Ocean remains the most poorly studied to date, since research is hampered by the fact that most of the ocean is hidden under ice cover.
. . The waters washing Antarctica combine signs. Allowing them to be separated into a separate ocean. But there is still debate about what should be considered boundaries. If the borders from the south are marked by the mainland, then the northern borders are most often drawn at 40-50º south latitude. Within these limits, the ocean area is 86 million square meters. km.
The bottom topography is indented by underwater canyons, ridges and basins. The fauna of the Southern Ocean is rich, with the largest number of endemic animals and plants.
Characteristics of the oceans
The world's oceans are several billion years old. Its prototype is the ancient ocean Panthalassa, which existed when all the continents were still a single whole. Until recently, it was assumed that the ocean floors were level. But it turned out that the bottom, like the land, has a complex topography, with its own mountains and plains.
Properties of the world's oceans
Russian scientist A. Voyekov called the World Ocean a “huge heating battery” of our planet. The fact is that the average water temperature in the oceans is +17ºC, and the average air temperature is +14ºC. Water takes much longer to heat up, but it also consumes heat more slowly than air, while having high heat capacity.
But not all water in the oceans has the same temperature. Under the sun, only surface waters heat up, and with depth the temperature drops. It is known that at the bottom of the oceans the average temperature is only +3ºC. And it remains this way due to the high density of water.
It should be remembered that the water in the oceans is salty, which is why it freezes not at 0ºC, but at -2ºC.
The degree of salinity of waters varies depending on latitude: in temperate latitudes the waters are less salty than, for example, in the tropics. In the north, the waters are also less saline due to the melting of glaciers, which greatly desalinize the water.
Ocean waters also vary in transparency. At the equator the water is clearer. As you move away from the equator, water becomes more quickly saturated with oxygen, which means more microorganisms appear. But near the poles, due to low temperatures, the waters become clearer again. Thus, the waters of the Weddell Sea near Antarctica are considered the most transparent. Second place belongs to the waters of the Sargasso Sea.
The difference between the ocean and the sea
The main difference between the sea and the ocean is its size. Oceans are much larger, and seas are often only part of the oceans. Seas also differ from the ocean to which they belong by a unique hydrological regime (water temperature, salinity, transparency, distinctive composition of flora and fauna).
Ocean climate
Pacific climate Infinitely diverse, the ocean is located in almost all climatic zones: from equatorial to subarctic in the north and Antarctic in the south. There are 5 warm currents and 4 cold currents circulating in the Pacific Ocean.
The greatest amount of precipitation falls in the equatorial belt. The amount of precipitation exceeds the share of water evaporation, so the water in the Pacific Ocean is less salty than in others.
Atlantic Ocean Climate determined by its large extent from north to south. The equator zone is the narrowest part of the ocean, so the water temperature here is lower than in the Pacific or Indian.
The Atlantic is conventionally divided into northern and southern, drawing the border along the equator, with the southern part being much colder due to its proximity to Antarctica. Many areas of this ocean are characterized by dense fogs and powerful cyclones. They are strongest near the southern tip of North America and in the Caribbean Sea.
For formation Indian Ocean climate The proximity of two continents - Eurasia and Antarctica - has a huge impact. Eurasia actively participates in the annual change of seasons, bringing dry air in winter and filling the atmosphere with excess moisture in summer.
The proximity of Antarctica causes a decrease in water temperature in the southern part of the ocean. Frequent hurricanes and storms occur north and south of the equator.
Formation climate of the Arctic Ocean determined by its geographical location. Arctic air masses dominate here. Average air temperature: from -20 ºC to -40 ºC, even in summer the temperature rarely rises above 0ºC. But the ocean waters are warmer due to constant contact with the Pacific and Atlantic oceans. Therefore, the Arctic Ocean warms a significant part of the land.
Strong winds are rare, but fog is common in summer. Precipitation falls mainly in the form of snow.
It is influenced by the proximity of Antarctica, the presence of ice and the absence of warm currents. The Antarctic climate prevails here with low temperatures, cloudy weather and gentle winds. Snow falls throughout the year. A distinctive feature of the Southern Ocean climate is high cyclone activity.
The influence of the ocean on the Earth's climate
The ocean has a tremendous influence on climate formation. It accumulates huge reserves of heat. Thanks to the oceans, the climate on our planet becomes softer and warmer, since the temperature of the waters in the oceans does not change as sharply and quickly as the air temperature over land.
The oceans promote better circulation of air masses. And such an important natural phenomenon as the water cycle provides the land with a sufficient amount of moisture.
) is the largest basin of the World Ocean. It is limited in the west by the shores of Eurasia and Australia, in the east by North and South America, and in the south by Antarctica. The maritime borders with the Arctic Ocean pass through the Bering Strait between the Chukotka and Seward peninsulas, with the Indian Ocean - along the northern edge of the Strait of Malacca, the western coast of the island of Sumatra, the southern coast of the islands of Java, Timor and New Guinea through the Torres and Bass Straits, along the eastern coast of Tasmania and further along the ridge of underwater rises to Antarctica, with the Atlantic Ocean - from the Antarctic Peninsula (Antarctica) along the rapids between the South Shetland Islands to Tierra del Fuego.
The area of the Pacific Ocean with seas is about 180 million km 2 (1/3 of the surface of the globe and 1/2 of the World Ocean), the volume of water is 710 million km 3. The Pacific Ocean is the deepest basin of the World Ocean, the average depth is 3980 m, the maximum in the trench area is 11,022 m (Mariana Trench). Includes the marginal seas in the north and west: Bering, Okhotsk, Japan, Yellow, East and South China, Philippine, Sulu, Sulawesi, Moluccas, Seram, Banda, Flores, Bali, Javanese, Savu, New Guinea, Coral, Fiji, Tasmanovo ; in the south - Ross, Amundsen, Bellingshausen. The largest bays are Alaska, California, and Panama. A characteristic feature of the Pacific Ocean is its numerous islands (especially in the central and southwestern parts of Oceania), in terms of the number (about 10,000) and area (3.6 million km2) of which this ocean ranks first among the basins of the World Ocean.
Historical sketch
The first scientific information about the Pacific Ocean was obtained at the beginning of the 16th century by the Spanish conquistador V. Nunez de Balboa. In 1520-21, F. Magellan first crossed the ocean from the strait named after him to the Philippine Islands. During the XVI-XVIII centuries. The ocean was studied on numerous voyages by naturalists. Russian sailors made a significant contribution to the exploration of the Pacific Ocean: S.I. Dezhnev, V.V. Atlasov, V. Bering, A.I. Chirikov and others. Systematic research has been carried out since the beginning of the 19th century. (geographical expeditions of I.F. Kruzenshtern, Yu.F. Lisyansky on the ships "Nadezhda" and "Neva", O.E. Kotzebue on the "Rurik" and then the "Enterprise", F.F. Bellingshausen and M.P. Lazarev on "Mirny"). A major event in the history of ocean exploration was the voyage of Charles Darwin on the Beagle (1831-36). The first actual oceanographic expedition was a circumnavigation of the world on the English ship Challenger (1872-76), in which extensive information was obtained about the physical, chemical, biological and geological features of the Pacific Ocean. The greatest contribution to the study of the Pacific Ocean at the end of the 19th century was made by scientific expeditions on ships: "Vityaz" (1886-89, 1894-96) - Russia, "Albatross" (1888-1905) - USA; in the 20th century: on the ships "Carnegie" (1928-29) - USA, "Snellius" (1929-30) - the Netherlands, "Discovery II" (1930) - Great Britain, "Galatea" (1950-52) - Denmark and "Vityaz" (since 1949 it has carried out over 40 flights) - USSR. A new stage in the exploration of the Pacific Ocean began in 1968, when deep-sea drilling began with the American vessel Glomar Challenger.
Relief and geological structure
Within the Pacific Ocean, a wide (up to several hundred kilometers) shelf is developed in marginal seas and along the coast of Antarctica.
Off the coast of North and South America the shelf is very narrow - up to several kilometers. The depth of the shelf is generally 100-200 m, off the coast of Antarctica up to 500 m. To the northwest of Cedros Island there is a unique area of the underwater margin of North America (California Borderland), represented by a system of underwater ridges and basins formed as a result of the attachment of alien bodies to the mainland. blocks (zone of accretionary tectonics) and rearrangement of plate boundaries during the collision of North America with the spreading axis of the East Pacific Rise. The continental slope from the shelf edge descends steeply to pelagic depths, the average slope steepness is 3-7°, the maximum is 20-30°. Active continental margins frame the ocean from the north, west and east, forming specific transition zones of lithospheric plate underthrust. In the north and west, transition zones are a combination of marginal seas, island arcs and deep-sea trenches. Most marginal seas were formed as a result of spreading that developed between island arcs and adjacent continental masses (back-arc spreading). In some cases, spreading zones passed along the edge of continental masses and their fragments were moved away and separated from the continents by marginal seas (New Zealand, Japan). Island arcs framing the seas are ridges of volcanoes, bounded on the ocean side by deep-sea trenches - narrow (tens of kilometers), deep (from 5-6 to 11 km) and extended depressions. On the eastern side, the ocean is framed by the active margin of the continent, where the oceanic plate is directly subducted under the continent. Subduction-related volcanism develops directly at the continental margin.
Within the ocean floor there is a system of active mid-ocean ridges (rift systems), located asymmetrically with respect to the surrounding continents (see map). The main ridge consists of several links: in the north - Explorer, Juan de Fuca, Gorda, south of 30° north latitude - the East Pacific Rise. The Galapagos and Chilean rift systems are also distinguished, which, approaching the main ridge, form specific areas of the triple junction. The rate of expansion of the ridges generally exceeds 5 cm/year, sometimes up to 16-18 cm/year. The width of the axial part of the ridge is several kilometers (extrusive zone), the depth is on average 2500-3000 m. At a distance of about 2 km. from the ridge axis the bottom is broken by a system of faults and grabens (tectonic zone). At a distance of 10-12 km. tectonic activity practically ceases, the slope of the ridge gradually passes into the adjacent deep-sea basins of the bed. The depth of the basalt ocean floor increases with distance from the ridge axis to the subduction zones, simultaneously with an increase in the age of the ocean crust. Areas of the ocean floor with a maximum bed age of about 150 million years are characterized by a depth of about 6000 m. The ocean floor is divided into basins by a system of uplifts and ridges (Northwestern, Northeastern, Central, Eastern Mariana, Western Carolina, East Carolina , Melanesian, Southern, Bellingshausen, Guatemala, Peruvian and Chilean, etc.). The bottom relief of the basins is predominantly wavy. About 85% of the area is occupied by very gentle hills up to 500 m high. Most of the uplifts, ridges, island systems separating the basins are of volcanic origin (islands: Hawaiian, Cocos, Caroline, Marshall, Gilbert, Tuvalu, Line, Phoenix, Tokelau, Cook, Tubuai, Marquesas, Tuamotu, Galapagos, etc.) - the volcanic rocks composing them are younger than the rocks of the ocean floor.
The section of the oceanic crust is represented (from bottom to top) by a cumulative complex of dunites and locally serpentinized pyroxenites, a homogeneous or layered gabbro layer, a basaltic layer (about 2 km thick), consisting of a dike complex (vertically standing parallel dikes) and underwater lavas, overlying the basalt layer sedimentary cover. With distance from the ridge, the age of the ocean floor and the thickness of sedimentary deposits increase. In the open ocean, the thickness of sediments is 100-150 m and increases in the northern and western direction, in the equatorial zone the thickness of sediments is up to 500-600 m. The thickness of sediments is sharply increased (up to 12-15 km) at the base of the continental slope and in marginal seas, which are traps for sedimentary material supplied from land.
Along the continents, mainly terrigenous sediments are developed (glacial and coastal in high latitudes, fluviogenic in temperate latitudes, aeolian in arid latitudes). In the pelagic zone of the ocean at a depth of less than 4000 m, carbonate foraminiferal and coccolithic oozes are almost universally developed, and in temperate zones - siliceous diatomaceous oozes. Deeper, within the equatorial highly productive zone, they are replaced by siliceous radiolarian and diatom sediments, and in tropical low-productive zones by red deep-sea clays. Along the active margins, the sediments contain a significant admixture of volcanogenic material. Sediments of the mid-ocean ridges and their slopes are enriched in oxides and hydroxides of iron and manganese, carried into the bottom waters by high-temperature ore-bearing solutions.
Mineral resources
In the depths of the Pacific Ocean, oil and gas deposits have been discovered, and at the bottom there are placers of heavy minerals and other minerals. The main oil and gas bearing areas are concentrated on the periphery of the ocean. Oil and gas fields have been discovered in the Tasman Basin - Barracouta (over 42 billion m 3 of gas), Marlin (more than 43 billion m 3 of gas, 74 million tons of oil), Kingfish, and the Kapuni gas field has been explored off the island of New Zealand (15 billion m3). The Indonesian seas, areas near the coast of South Alaska and the western shores of North America are also promising for oil and gas. Among solid minerals, alluvial deposits of magnetite sands (Japan, the western coast of North America), cassiterite (Indonesia, Malaysia), gold and platinum (the coast of Alaska, etc.) have been discovered and are partially being developed. Large accumulations of deep-sea iron-manganese nodules, which also contain significant amounts of nickel and copper, have been discovered in the open ocean (Clarion-Clipperton fault). On many seamounts and slopes of oceanic islands, iron-manganese crusts and nodules enriched in cobalt and platinum have been discovered. Within the mid-ocean rifts and in the area of back-arc spreading (in the western part of the Pacific Ocean), large deposits of sulfide ores containing zinc, copper, lead and rare metals have been discovered (East Pacific Rise, Galapagos Rift). Phosphorite deposits are known on the shelves of California and the island of New Zealand. In many shallow areas of the shelf, deposits of non-metallic minerals have been identified and are being exploited.
Mineralogical finds
(! - remarkable in some respect; !! - outstanding; * new mineral (year of publication); (PM\TL) - original location of the mineral \ type locality; xls - crystals) Mineralogical finds around the Pacific Ocean (examples). II. From Alaska to Antarctica - http://geo.web.ru/druza/a-Ev_33_32_E.htm
Mineralogical finds around the Pacific Ocean (examples). I. From Chukotka to Antarctica - http://geo.web.ru/druza/a-Ev_33_32.htm
Mineral Locations
- Viti Levu Island, Fiji \\ sylvanite - crystals up to 1 cm (Korbel, 2004, 41)
- East Pacific Rise \\ East Pacific Rise \\ wurtzite; graphite; * caminite (PM\TL) (1983; 1986); sulfides are massive!
1. Pacific Ocean
2. Indian Ocean
3. Atlantic Ocean
4. Arctic Ocean
Pacific Ocean
The world ocean embraces the Earth with inseparable waters and is by its nature a single element, which acquires different properties with changes in latitude. Off the coast of Greenland and Antarctica, in the roaring winds of the forties, storms rage all year round. In the tropics, the sun bakes mercilessly, trade winds blow, and only occasionally do destructive hurricanes sweep through. But the vast World Ocean is also divided by continents into separate oceans, each of which has its own special natural features.
The Pacific Ocean is the largest in area, the deepest and the oldest of the oceans. Its main features are great depths, frequent movements of the earth's crust, many volcanoes at the bottom, a huge supply of heat in its waters, and an exceptional diversity of the organic world.
The Pacific Ocean, also called the Great Ocean, occupies 1/3 of the surface of the planet and almost 1/2 of the area of the World Ocean. It is located on both sides of the equator and the 1800 meridian. This ocean divides and at the same time connects the shores of five continents. The Pacific Ocean is particularly wide near the equator, so it is warmest at the surface.
In the east of the ocean, the coastline is poorly dissected; several peninsulas and bays stand out. In the west the shores are heavily indented. There are many seas here. Among them there are shelf ones, located on the continental shallows, with depths of no more than 100 m. Some seas lie in the zone of interaction of lithospheric plates. They are deep and separated from the ocean by island arcs.
Since ancient times, many peoples inhabiting the Pacific coasts and islands have sailed the ocean and developed its riches. The beginning of the penetration of Europeans into the Pacific Ocean coincided with the era of the Great Geographical Discoveries. F. Magellan's ships crossed a huge expanse of water from east to west over several months of sailing. All this time the sea was surprisingly calm, which gave Magellan reason to call it the Pacific Ocean.
Much information about the nature of the ocean was obtained during the voyages of J. Cook. Russian expeditions led by I. F. Kruzenshtern, M. P. Lazarev, V. M. Golovnin, Yu. F. Lisyansky made a great contribution to the study of the ocean and the islands in it. In the same XIX century. complex studies were carried out by S. O. Makarov on the ship “Vityaz”. Since 1949, regular scientific voyages have been carried out by Soviet expeditionary vessels. A special international organization is studying the Pacific Ocean.
The topography of the ocean floor is complex. The continental shoal (shelf) is well developed only off the coasts of Asia and Australia. Continental slopes are steep, often stepped. Large rises and ridges divide the ocean floor into basins. Near America is the East Pacific Rise, which is part of the system of mid-ocean ridges. On the ocean floor there are more than 10 thousand individual seamounts, mostly of volcanic origin.
The lithospheric plate on which the Pacific Ocean lies interacts with other plates at its boundaries. The edges of the Pacific Plate are plunging into a tight space of trenches that ring the ocean. These movements give rise to earthquakes and volcanic eruptions. Here lies the famous “Ring of Fire” of the planet and the deepest trench - the Mariana Trench (11022 m).
The ocean climate is varied. The Pacific Ocean is located in all climate zones except the North Polar. Above its vast expanses the air is saturated with moisture. In the equator region, up to 2000 mm of precipitation falls. The Pacific Ocean is protected from the cold Arctic Ocean by land and underwater ridges, so its northern part is warmer than its southern part.
The Pacific Ocean is the most restless and formidable among the oceans of the planet. Trade winds blow in its central parts. In the west, monsoons are developed. In winter, a cold and dry monsoon comes from the mainland, which has a significant impact
influence on ocean climate; Some of the seas are covered with ice. Often devastating tropical hurricanes sweep over the western part of the ocean - typhoons (typhoon means “strong wind”). In temperate latitudes, storms rage throughout the cold half of the year. Western air transport prevails here. The highest waves up to 30 m high are recorded in the north and south of the Pacific Ocean. Hurricanes raise entire mountains of water in it.
The properties of water masses are determined by climate characteristics. Due to the large extent of the ocean from north to south, the average annual surface water temperature varies from -1 to +29 °C. In general, precipitation in the ocean predominates over evaporation, so the salinity of its surface waters is somewhat lower than in other oceans.
Currents in the Pacific Ocean are consistent with their general pattern in the World Ocean, which you already know. Since the Pacific Ocean is strongly elongated from west to east, latitudinal water flows predominate in it. In both the northern and southern parts of the ocean, ring-shaped movements of surface waters are formed.
The organic world of the Pacific Ocean is distinguished by its extraordinary richness and diversity of plant and animal species. It is home to half of the total mass of living organisms in the World Ocean. This feature of the ocean is explained by its size, diversity of natural conditions and age. Life is especially rich in tropical and equatorial latitudes near coral reefs. In the northern part of the ocean there are many salmon fish. In the southeast of the ocean, near the coast of South America, huge accumulations of fish form. The water masses here are very fertile, they develop a lot of plant and animal plankton, which feed on anchovies (herring-like fish up to 16 cm long), horse mackerel, butterfish, mackerel and other types of fish.A lot of fish are eaten here by birds: cormorants, pelicans, penguins.
The ocean is home to whales, fur seals, and sea beavers (these pinnipeds live only in the Pacific Ocean). There are also many invertebrate animals - corals, sea urchins, mollusks (octopus, squid). The largest mollusk, the tridacna, lives here, weighing up to 250 kg.
Each of the Pacific Ocean belts has its own characteristics. The northern subpolar belt occupies a small part of the Bering and Okhotsk seas. The temperature of the water masses here is low (up to -1 °C). In these seas there is active mixing of waters, and therefore they are rich in fish (pollock, flounder, herring). There are many salmon fish and crabs in the Sea of Okhotsk.
Vast territories are covered by the northern temperate zone. It is strongly influenced by westerly winds and storms are frequent here. In the west of this belt lies the Sea of Japan - one of the richest in diverse species of organisms.
In the equatorial belt, at the boundaries of currents, where the rise of deep waters to the surface increases and their biological productivity increases, many fish live (sharks, tuna, sailfish, etc.).
In the southern tropical zone of the Pacific Ocean off the coast of Australia there is a unique natural complex of the Great Barrier Reef. This is the largest “mountain range” on Earth created by living organisms. In size it is comparable to the Ural Range. Under the protection of islands and reefs in warm waters, coral colonies develop in the form of bushes and trees, columns, castles, bouquets of flowers, mushrooms; corals are light green, yellow, red, blue, purple. Many mollusks, echinoderms, crustaceans, and various fish live here.
There are more than 50 coastal countries on the shores and islands of the Pacific Ocean, home to approximately half of humanity.
The use of the natural resources of the ocean began in ancient times. Several centers of navigation arose here - in China, in Oceania, in South America, on the Aleutian Islands.
The Pacific Ocean plays an important role in the lives of many peoples. Half of the world's fish catch comes from this ocean. In addition to fish, part of the catch consists of various shellfish, crabs, shrimp, and krill. In Japan, algae and shellfish are grown on the seabed. In some countries, salt and other chemicals are extracted from sea water and desalinated. Placer metals are being mined on the shelf. Oil is being extracted off the coast of California and Australia. Ferromanganese ores were discovered on the ocean floor.
Important transport routes pass through the greatest ocean of our planet; the length of these routes is very large. Shipping is well developed, mainly along the coasts of the continents.
Human economic activity in the Pacific Ocean has led to the pollution of its waters and the depletion of some types of biological resources. So, by the end of the 18th century. mammals were exterminated - sea cows (a species of pinnipeds), discovered by one of the participants in V. Bering's expedition. On the verge of extermination at the beginning of the twentieth century. there were seals, the number of whales decreased. Currently, their fishing is limited. A great danger in the ocean is water pollution with oil, some heavy metals and waste from the nuclear industry. Harmful substances are carried by currents throughout the ocean. Even off the coast of Antarctica, these substances were found in marine organisms.
Indian Ocean
The nature of the Indian Ocean has many similarities with the nature of the Pacific Ocean, especially many similarities in the organic world of the two oceans.
The Indian Ocean has a unique position on the planet: most of it lies in the Southern Hemisphere. In the north it is limited to Eurasia and has no connection with the Arctic Ocean.
The ocean shores are slightly indented. There are relatively few islands. Large islands are located only on the border of the ocean. There are volcanic and coral islands in the ocean
From the history of ocean exploration. The shores of the Indian Ocean are one of the areas of ancient civilizations. Some scientists believe that navigation began in the Indian Ocean. The first means of overcoming expanses of water could be bamboo rafts, which are still used in Indochina. Catamaran-type ships were created in India. Images of such ships are carved on the walls of ancient temples. Ancient Indian sailors in those distant times sailed to Madagascar, East Africa, and possibly to America. The Arabs were the first to write descriptions of ocean voyage routes. Information about the Indian Ocean began to accumulate since the voyage of Vasco da Gama (1497-1499). At the end of the 18th century. The first measurements of the depths of this ocean were carried out by the English navigator J. Cook.
Comprehensive study of the ocean began at the end of the 19th century. The most significant research was carried out by the British expedition on the Challenger ship. However, until the middle of the twentieth century. The Indian Ocean has been poorly studied. Nowadays, dozens of expeditions on research vessels from many countries are studying the nature of the ocean and revealing its riches.
The structure of the bottom topography is complex. Mid-ocean ridges divide the ocean floor into three parts. In the western part there is a ridge connecting south of Africa with the Mid-Atlantic Ridge. The center of the ridge is characterized by deep faults, areas of earthquakes and volcanism on the ocean floor. Fractures in the earth's crust continue in the Red Sea and reach land.
The climate of this ocean is influenced by its geographical location. A special feature of the climate is the seasonal monsoon winds in the northern part of the ocean, which is located in the subequatorial zone and is subject to significant influence from land. Monsoons have a huge impact on weather conditions in the northern part of the ocean.
In the south, the ocean experiences the cooling influence of Antarctica; This is where the harshest areas of the ocean lie.
The properties of water masses are associated with climate characteristics. The northern part of the ocean warms up well, is deprived of the influx of cold water and is therefore the warmest. The water temperature here is higher (up to +30 °C) than at the same latitudes in other oceans. To the south, the water temperature decreases. The salinity of ocean waters at the surface is generally higher than the average salinity of the World Ocean, and in the Red Sea it is especially high (up to 42‰).
In the northern part of the ocean, the formation of currents is influenced by seasonal changes in winds. Monsoons change the direction of movement of waters, cause their vertical mixing, and rearrange the system of currents. In the south, the currents are part of the general pattern of currents in the World Ocean.
The organic world of the Indian Ocean is similar to the flora and fauna of the western Pacific Ocean. Tropical water masses are rich in plankton, which is especially rich in unicellular algae. Because of them, the surface layer of water becomes very cloudy and changes color. Among the plankton there are many organisms that glow at night. There are various types of fish: sardinella, mackerel, sharks. In the southern part of the ocean there are white-blooded fish, such as ice fish, etc. Shelf areas and shallow waters near coral reefs are especially rich in life. Algae thickets form underwater meadows. The warm waters of the Indian Ocean are home to giant sea turtles, sea snakes, a lot of cuttlefish and squid, and near Antarctica - whales and seals.
The Indian Ocean is located in several natural zones. In the tropical zone, under the influence of the surrounding land, complexes with different properties of water masses are formed. In the western part of this belt there is little precipitation, evaporation is high, and almost no water comes from land. The water masses here have high salinity. The northeastern part of the belt, on the contrary, receives a lot of rainfall and fresh water from rivers flowing from the Himalayas. A complex with highly desalinated surface waters is created here.
The natural resources of the Indian Ocean as a whole have not yet been sufficiently studied and developed. The ocean shelf is rich in minerals. There are huge deposits of oil and natural gas in the sedimentary rocks at the bottom of the Persian Gulf. Oil production and transportation pose a risk of water pollution. In countries located off the northwestern coasts of the ocean, where there is almost no fresh water, salt water is being desalinated. Fishing is also developed.
Numerous shipping routes pass through the Indian Ocean. There are especially many sea roads in the northern part of the ocean, where small sailing ships are still used. The direction of their movement is associated with the monsoons.
Atlantic Ocean
Of all the oceans, the Atlantic occupies the most important place in the life of mankind. This happened historically.
Like the Pacific Ocean, the Atlantic Ocean extends from subarctic latitudes to Antarctica, but is inferior to it in width. The Atlantic reaches its greatest width in temperate latitudes and narrows towards the equator.
The ocean coastline is strongly dissected in the Northern Hemisphere, and weakly indented in the Southern Hemisphere. Most of the islands lie near the continents.
Since ancient times, the Atlantic Ocean began to be developed by man. Navigation centers in Ancient Greece, Carthage, and Scandinavia arose on its shores in different eras. Its waters washed the legendary Atlantis, the geographical position of which in the ocean is still debated by scientists.
Since the Age of Discovery, the Atlantic Ocean has become the main waterway on Earth.
Comprehensive studies of the nature of the Atlantic began only at the end of the 19th century. The English expedition on the ship Challenger took depth measurements and collected material about the properties of water masses and the organic world of the ocean. Especially a lot of data on the nature of the ocean was obtained during the International Geophysical Year (1957-1958). And today, an expeditionary squadron of science ships from many countries continues to conduct research on water masses and bottom topography. Oceanologists study the interaction of the ocean with the atmosphere and study the nature of the Gulf Stream and other currents.
According to the theory of lithospheric plates, the Atlantic Ocean is relatively young. The topography of its bottom is not as complex as in the Pacific Ocean. A gigantic ridge stretches across the entire Atlantic, almost along the meridian. In one place it comes to the surface - this is the island of Iceland. The ridge divides the ocean floor into two almost equal parts. Vast shelves adjoin the coasts of Europe and North America.
The climate of the Atlantic Ocean is varied, as it lies in all climate zones. The widest part of the ocean lies not in equatorial latitudes, like the Pacific Ocean, but in tropical and temperate latitudes. In these latitudes, as well as over the Pacific Ocean, trade winds and westerly winds of temperate latitudes blow. In winter, storms often occur in temperate latitudes; in the Southern Hemisphere, they rage in all seasons of the year.
The peculiarities of the climate are reflected in the properties of water masses. The surface water temperature here is on average significantly lower than in the Pacific and Indian oceans. This is explained by the cooling influence of water and ice carried out from the Arctic Ocean and Antarctica, as well as intense mixing of water masses. Noticeable differences between water and air temperatures in several areas of the Atlantic cause the formation of strong fogs.
The salinity of water masses in some areas of the ocean is higher than average, since a significant part of the evaporated moisture, due to the relative narrowness of the ocean, is transported by winds to neighboring continents.
Currents in the Atlantic, unlike the Pacific and Indian Oceans, are not directed along latitude, but almost along the meridians. The reasons for this are the large elongation of the ocean from north to south and the outline of the coastline. Currents in the Atlantic are more active than in other oceans, transporting water masses, and with them heat and cold, from one latitude to another. Currents also affect ice conditions. The ocean is characterized by numerous icebergs and floating sea ice. The waters near Greenland are one of the most picturesque areas of the Atlantic. Powerful ice “tongues” emerge from the depths of the island to the ocean and hang over its cold bluish-green waters with high cliffs of transparent ice. At times they break off with a roar and large chunks fall into the water. Currents carry icebergs into the open ocean up to 40° N. w. These areas of the Atlantic are dangerous for shipping. The movement of icebergs is monitored by a special air patrol service; images are also received from artificial Earth satellites. This information is transmitted to ships of all countries.
The organic world of the Atlantic is poorer in species than the world of the Pacific. This is explained by the relative youth of the Atlantic Ocean and the strong cooling of its climate during the last glaciation. With a small number of species, the number of fish and other marine animals in this ocean is significant. There are more shelves and bottom rises here than in the Pacific Ocean. Therefore, there are many convenient places for spawning bottom and demersal fish, including commercial ones: cod, herring, mackerel, sea bass, capelin. Whales and seals live in polar waters. Like the Pacific Ocean, the Atlantic has almost all natural zones. Within them there are natural complexes of seas and bays (Mediterranean, Northern, Baltic and other seas). By their nature they differ from the complexes of the open ocean.
In the northern subtropical zone there is the Sargasso Sea, unique in its nature - a sea without shores. Its boundaries are formed by currents. The waters of this sea have high salinity (up to 37‰) and temperature. On the bright blue surface of the ocean, small tufts of sargassum algae appear as green-brown spots. The sea waters are poor in plankton. Birds are also very rare here. Oceanologists call such areas “blue ocean deserts.”
Economically developed countries lie on both sides of the ocean. The most important sea routes pass through the Atlantic. Since time immemorial, the Atlantic Ocean has been a place of intensive fishing and hunting. Whaling in the Bay of Biscay was carried out in the 9th-12th centuries.
The natural conditions of the Atlantic are favorable for the development of life, therefore it is the most productive of all the oceans. Most of the fish catch and production of other marine products occurs in the northern part of the ocean. However, increased fishing has recently led to a decrease in biological wealth.
The Atlantic Ocean shelves are rich in oil and other mineral deposits. Thousands of wells have been drilled offshore the Gulf of Mexico and the North Sea. Due to the growth of cities, the development of shipping in many seas and in the ocean itself, a deterioration in natural conditions has recently been observed. The waters and air are polluted, and conditions for recreation on the shores of the ocean and its seas have deteriorated. For example, the North Sea is covered with many kilometers of oil slicks. Off the coast of North America, the oil film is hundreds of kilometers wide. The Mediterranean Sea is one of the most polluted on Earth. The Atlantic is no longer able to clean itself of waste on its own. The fight against pollution in this ocean is an international matter. Treaties have already been concluded that prohibit the dumping of hazardous waste into the ocean.
Arctic Ocean
This ocean is distinguished by its harsh climate, abundance of ice and relatively shallow depths. Life there is entirely dependent on the exchange of water and heat with neighboring oceans.
The Arctic Ocean is the smallest of the Earth's oceans. It is the shallowest. The ocean is located in the center of the Arctic, which occupies the entire space around the North Pole, including the ocean, adjacent parts of the continents, islands and archipelagos.
A significant part of the ocean area is made up of seas, most of which are marginal and only one is internal. There are many islands in the ocean located near the continents.
History of ocean exploration. The exploration of the Arctic Ocean is the story of the heroic exploits of many generations of sailors, travelers and scientists from a number of countries. In ancient times, Russian people - Pomors - set out on journeys on fragile wooden boats and boats. They spent the winter on Grumant (Spitsbergen) and sailed to the mouth of the Ob. They fished, hunted sea animals and knew well the conditions of navigation in polar waters.
Using information about Russian voyages, the British and Dutch attempted to find the shortest routes from Europe to the countries of the East (China and India). As a result of the voyage of Willem Barents at the end of the 16th century. a map of the western part of the ocean was compiled.
The systematic study of the ocean shores began with the Great Northern Expedition (1733-1743). Its participants accomplished a scientific feat - they walked and mapped the coast from the mouth of the Pechora to the Bering Strait.
The first information about the nature of the circumpolar regions of the ocean was collected at the end of the 19th century. during the drift of Fram Nansen and the voyage to the Pole at the beginning of the twentieth century. G. Sedova on the schooner “St. Foka."
The possibility of crossing the ocean in one navigation was proven in 1932 by the expedition of the icebreaker Sibiryakov. The participants of this expedition, under the leadership of O. Yu. Schmidt, took depth measurements, measured the thickness of the ice, and observed the weather.
Our country has developed new methods for studying this ocean. In 1937, the first polar station “North Pole” (SP-1) was established on a drifting ice floe. Four polar explorers led by I.D. Papanin carried out a heroic drift on an ice floe from the North Pole to the Greenland Sea.
To study the ocean, they now use airplanes that land on ice floes and carry out one-time observations. Images from space provide information about changes in the state of the atmosphere over the ocean and the movement of ice.
As a result of all these studies, a large amount of material has been accumulated about the nature of the Arctic Ocean: about the climate, the organic world; the structure of the bottom topography was clarified, bottom currents were studied.
Many secrets of the nature of the Arctic Ocean are already known, but much remains to be discovered by future generations, including, perhaps, some of you.
The bottom topography has a complex structure. The central part of the ocean is crossed by mountain ranges and deep faults. Between the ridges there are deep-sea depressions and basins. A characteristic feature of the ocean is a large shelf, which makes up more than a third of the ocean floor area.
Climatic features are determined by the polar position of the ocean. Arctic air masses prevail over it. Fogs are frequent in summer. Arctic air masses are much warmer than air masses forming over Antarctica. The reason for this is the heat reserve in the waters of the Arctic Ocean, which is constantly replenished by the heat of the waters of the Atlantic and, to a lesser extent, the Pacific Ocean. Thus, oddly enough, the Arctic Ocean does not cool, but significantly warms the vast land areas of the Northern Hemisphere, especially in the winter months.
Under the influence of western and southwestern winds from the North Atlantic, a powerful flow of warm waters of the North Atlantic Current enters the Arctic Ocean. Along the coast of Eurasia, waters move from west to east. Across the entire ocean from the Bering Strait to Greenland, water moves in the opposite direction - from east to west.
The most characteristic feature of the nature of this ocean is the presence of ice. Their formation is associated with the low temperature and relatively low salinity of surface water masses, which are desalinated by a large amount of river water flowing from the continents.
The removal of ice to other oceans is difficult. Therefore, multi-year ice with a thickness of 2-4 m or more prevails here. Winds and currents cause the movement and compression of ice, the formation of hummocks.
The bulk of organisms in the ocean are algae, which can live in cold water and even on ice. The organic world is rich only in the Atlantic region and on the shelf near river mouths. Plankton is formed here, algae grows on the bottom, and fish live (cod, navaga, halibut). Whales, seals, and walruses live in the ocean. The Arctic is inhabited by polar bears and seabirds that lead a colonial lifestyle and live on the shores. The entire population of the giant “bird colonies” feeds in the ocean.
There are two natural zones in the Arctic Ocean. The boundary of the polar (Arctic) belt in the south approximately coincides with the edge of the continental shelf. This deepest and harshest part of the ocean is covered with drifting ice. In summer, the ice floes are covered with a layer of melt water. This belt is unsuitable for living organisms.
The part of the ocean adjacent to land belongs to the subpolar (subarctic) belt. These are mainly the seas of the Arctic Ocean. Nature here is not so harsh. In summer, the water off the coast is free of ice and is highly desalinated by rivers. Warm waters from the Atlantic penetrating here create conditions for the development of plankton, which fish feed on.
Types of economic activities in the ocean. The Arctic Ocean is of exceptional importance for the countries whose shores are washed by its waters. The harsh nature of the ocean makes it difficult to search for minerals. But oil and natural gas deposits have already been explored on the shelf of the Kara and Barents Seas, off the coast of Alaska and Canada.
The biological wealth of the ocean is small. In the Atlantic region they fish and obtain seaweed, and hunt seals. Whale production in the ocean is strictly limited.
The development of the Northern Sea Route began only in the 30s. XX century The Northern Sea Route (abbreviated NSR) is the main shipping route in the Arctic, which significantly reduces the distances between European and Far Eastern ports. The NSR plays a huge role in the development of Siberia. Equipment and food are transported to Siberia along this route, and timber and ore are exported. Navigation lasts from 2 to 4 months, and in some areas with the help of icebreakers its duration is longer. To ensure the operation of the Northern Sea Route, special services have been created in our country: polar aviation, a whole network of meteorological stations on the coast and on drifting ice floes.
The Arctic Ocean is studied by people who are called by the expressive word “polar explorers”. Belonging to polar explorers is determined not only by profession, but also by geographical area of activity. Despite the fact that a person is armed with powerful technology, working in the Arctic Ocean is difficult and dangerous. Polar explorers are characterized not only by courage and courage, endurance and hard work, but also by high professional skills.
The Pacific Ocean is the largest of the oceans. Its area is 178.7 million km 2. The ocean is larger in area than all the continents taken together, and has a rounded configuration: noticeably elongated from northwest to southeast, so air and water masses reach their greatest development 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 volume of waters of the World Ocean). The average ocean depth is 3980 m, the maximum is 11,022 m (Mariana Trench).
The ocean washes the shores of almost all continents with its waters, except Africa. It reaches Antarctica with a wide front, and its cooling influence extends through the waters far to the north. On the contrary, Quiet is protected from cold air masses by its 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 half. The Pacific Ocean basin is connected to all other oceans. The boundaries between them are quite arbitrary. The most reasonable border is 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 Cape Horn in the archipelago - Cape Sterneck on the Antarctic Peninsula). The border with the Indian Ocean is arbitrary.
It is usually carried out as follows: the Malay archipelago is attributed 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 boundary with the Southern Ocean ranges from 36° S. w. off the coast of South America to 48° S. w. (at 175° W). The outlines of the coastline are quite simple on the eastern edge of the ocean and very complex on the western edge, where the ocean occupies a complex of marginal and interisland seas, island arcs and deep-sea trenches. This is a vast area of the largest horizontal and vertical division of the earth's crust on Earth. The marginal type includes seas off the coasts of Eurasia and Australia. Most of the interisland seas are located in the Malay Archipelago region. They are often combined under the general name Australasian. 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 are unparalleled in the Pacific Ocean. The coasts of North and South America are slightly indented; there are no marginal seas or such large clusters of islands. Deep-sea trenches are located directly off the coasts of continents. Off the coast of Antarctica in the Pacific sector there are three large marginal seas: Ross, Amundsen and Bellingshausen.
The margins 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 huge size of the Pacific Ocean is associated with its unique records: it is the deepest, the warmest on the surface, the highest wind waves, the most destructive tropical hurricanes and tsunamis are formed here, etc. 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 the largest region of multilateral economic activity and diverse interests of mankind. Since ancient times, residents of the Pacific coasts and islands have developed the biological resources of coastal waters and made short voyages. Over time, other resources began to be involved in the economy, and their use gained wide industrial scope. Nowadays, the Pacific Ocean plays a very important role in the lives of many countries and peoples, which is largely determined by its natural conditions, economic and political factors.
Features of the economic and geographical position of the Pacific Ocean
In the north, vast expanses of the Pacific Ocean are connected to the Arctic Ocean through the Bering Strait.
The border between them runs along a conventional line: Cape Unikyn (Chukchi Peninsula) - Shishmareva Bay (Seward Peninsula). In the west, the Pacific Ocean is limited by the Asian mainland, 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 following along the shores of the island of Tasmania, and to the south along a ridge of underwater rises to Cape Alden on Wilkes' Land. The eastern limits of the ocean are the shores of North and South America, and to the south there 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 Antarctica. Within these limits, it occupies an area of 179.7 million km 2, including marginal seas.
The ocean has a spherical shape, especially pronounced in the northern and eastern parts. Its greatest latitudinal extent (about 10,500 miles) is noted along the parallel of 10° N, and its greatest length (about 8,500 miles) falls on the meridian 170° W. Such large distances between the northern and southern, western and eastern shores are an essential natural feature of this ocean.
The ocean coastline is heavily indented in the west, while in the east the shores are mountainous and poorly dissected. In the north, west and south of the ocean there are large seas: Bering, Okhotsk, Japan, Yellow, East China, South China, Sulawesi, Javanese, Ross, Amundsen, Bellingshausen, etc.
The bottom relief of the Pacific Ocean is complex and uneven. In most of the transition zone, the shelves do not have significant development. For example, off the American coast the width of the shelf does not exceed several tens of kilometers, but in the Bering, East China, and South China Seas it reaches 700-800 km. In general, shelves occupy about 17% of the entire transition zone. The continental slopes are steep, often stepped, dissected by submarine canyons. The ocean bed occupies a huge space. A system of large uplifts, ridges and individual mountains, wide and relatively low shafts, it is divided into large basins: North-Eastern, North-Western, East Mariana, West Carolina, Central, South, etc. The most significant East Pacific Rise is included in the world's system of mid-ocean ridges. In addition to it, large ridges are common in the ocean: Hawaiian, Imperial Mountains, Caroline, Shatsky, etc. A characteristic feature of the topography of the ocean floor is that the greatest depths are confined to its periphery, where deep-sea trenches are located, most of which are concentrated in the western part of the ocean - from the Gulf of Alaska to New Zealand.
The vast expanses of the Pacific Ocean cover all natural zones from the northern subpolar to the southern polar, which determines the diversity of its climatic conditions. At the same time, the most significant part of the ocean space, located between 40° N. w. 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 part. Due to the cooling influence of the Asian continent and the predominance of west-east transport, the temperate and subtropical latitudes of the western part of the ocean are characterized by typhoons, especially frequent in June-September. The northwestern part of the ocean is characterized by monsoons.
Its exceptional size, unique shape, and large-scale atmospheric processes largely determine the characteristics of the hydrological conditions of the Pacific Ocean. Since quite a 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 equal to 19’37°. The predominance of precipitation over evaporation and large river runoff determine the lower salinity of surface waters than in other oceans, the average value of which is 34.58% o.
Temperature and salinity on the surface vary both over the water area and over the seasons. Temperature changes most noticeably over the seasons in the western part of the ocean. Seasonal variations in salinity are small throughout. 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 consists of horizontal and vertical movements of water, which can be traced to one degree or another 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 Northern Trade Wind, Kuroshio, North Pacific warm currents, California, Kuril cold and Alaskan warm currents. The system of circular currents in the southern regions of the ocean includes the 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 Intertrade Current, passing north of the equator, in the band between 2-4° and 8-12° N latitude. The speeds of surface currents vary in different areas of the ocean and vary with the seasons. Vertical water movements of different mechanisms and intensity are developed throughout the ocean. Density mixing occurs in the surface horizons, especially significant in areas of ice formation. In zones of convergence of surface currents, surface waters sink and underlying waters rise. The interaction of surface currents and vertical movements of water is one of the most important factors in the 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 the social and economic conditions characterized by the EGP of the Pacific Ocean. In relation to land areas gravitating towards the ocean, EGP has its own distinctive features. The Pacific Ocean and its seas wash the coasts of three continents, on which there are more than 30 coastal states with a total population of about 2 billion people, i.e. About half of humanity lives here.
Countries facing the Pacific Ocean include Russia, China, Vietnam, the USA, Canada, Japan, Australia, Colombia, Ecuador, Peru, etc. Each of the three main groups of Pacific 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 sea coasts form a continuous front, which facilitates economic maneuvering in its individual sections. However, the Pacific Ocean is significantly remote 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 still it significantly influences the nature of our connections with this ocean.
Almost all mainland states and many island states, with the exception of Japan, adjacent to the Pacific Ocean, have large reserves of various natural resources that are being intensively developed. Consequently, sources of raw materials are distributed 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 uniform distribution of natural resources along the ocean coast and the confinement of their consumption to certain areas is a characteristic feature of the EGP of the Pacific Ocean.
Continents and partly islands over 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 broad front to the waters of the Indian Ocean, and through the Strait of Magellan and the Drake Passage to the waters of the Atlantic. In the north, the Pacific Ocean is connected to the Arctic Ocean by the Bering Strait. In general, the Pacific Ocean, excluding its Antarctic regions, is connected in a relatively small part with other oceans. The routes and its communications with the Indian Ocean pass through the Australasian seas and their straits, and with the Atlantic - through the Panama Canal and the Strait of Magellan. The narrowness of the straits of the seas of Southeast Asia, the limited capacity of the Panama Canal, and the remoteness of vast areas of Antarctic waters from major world centers reduce the transport capabilities of the Pacific Ocean. This is an important feature of its EGP in relation to world sea routes.
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 issues of its evolution remain unclear. Regarding the Pacific Ocean, there is much indirect evidence indicating that the paleo-Pacific Ocean has existed since the mid-Precambrian. It washed the only continent of the Earth - Pangea-1. It is believed that direct evidence of the antiquity of the Pacific Ocean, despite the youth of its modern crust (160-180 million years), is the presence of ophiolite associations of rocks in folded systems found throughout the continental periphery of the ocean and having an age up to the Late Cambrian. The history of the development of the ocean in Mesozoic and Cenozoic times has been more or less reliably restored.
The Mesozoic stage appears to have 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 young Indian and Atlantic oceans opened. 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 sank into the mantle (subduction) in the Zavaritsky-Benioff zones, which bordered the ocean, as at the present time, in an almost continuous strip. At this stage of the development of the Pacific Ocean, a restructuring of its ancient mid-ocean ridges took place.
The formation of folded structures in northeast 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 continents pushing against it. As a result of the continuous movement of America to the west and the absorption of the ocean floor, the system of its median ridges turned out to be significantly shifted 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 waters also formed, and the island arcs of this part of the ocean acquired their modern appearance. In the north, with the formation of the Aleutian island arc, the Bering Sea became detached, the Bering Strait opened, and the cold waters of the Arctic began to flow into the Pacific Ocean. Off the coast of Antarctica, basins of the Ross, Bellingshausen and Amundsen seas took shape. There was a major fragmentation of the land connecting 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 appearance. 40-30 million years ago, an isthmus formed between the Americas, and the connection between the Pacific Ocean and the Atlantic Ocean in the Caribbean region was completely interrupted.
Over the past 1-2 million years, the size of the Pacific Ocean has decreased very slightly.
Main features of the bottom topography
As in other oceans, all the main planetary morphostructural zones are clearly distinguished in the Pacific: the underwater margins of continents, transition zones, the ocean floor and mid-ocean ridges. But the general plan of the bottom relief, the ratio of areas and the location of these 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 area of the Pacific Ocean, which is significantly less compared to other oceans. The continental shallows (shelf) account for 5.4%.
The shelf, like the entire underwater margin of the continents, reaches its greatest development in the western (Asian-Australian) continental sector, in the marginal seas - the Bering, Okhotsk, Yellow, East China, South China, seas of the Malay Archipelago, as well as to the north and east from Australia. The shelf is wide in the northern Bering Sea, where there are flooded river valleys and traces of relict glacial activity. In the Sea of Okhotsk, a submerged shelf (1000-1500 m deep) is developed.
The continental slope is also wide, with signs of fault-block dissection, and is cut through by large underwater canyons. The continental base is a narrow trail of accumulation of products carried out by turbidity currents and landslide masses.
To the north of Australia there is a vast continental shelf with widespread development of coral reefs. In the western part of the Coral Sea there is a unique structure on Earth - the Great Barrier Reef. This is an intermittent strip of coral reefs and islands, shallow bays and straits, stretching in the meridional direction for almost 2500 km, in the northern part the width is about 2 km, 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 layer (up to 1000-1200 m) of dead coral limestone, accumulated during the 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 a vast shallow lagoon - a strait up to 200 km wide and no more than 50 m deep. In the east, the reef breaks off like an almost vertical wall towards the continental slope.
The underwater margin of New Zealand represents a unique structure. The New Zealand plateau consists of two flat-topped rises: Campbell and Chatham, separated by a depression. The underwater plateau is 10 times larger than the area of the islands themselves. This is a huge block of continental-type earth's crust, with an area of about 4 million km 2, not connected to any of the nearest continents. On almost all sides the plateau is limited 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 leveled shelf. The continental slope is heavily indented by numerous submarine canyons.
The area of the underwater margin located to the west of California and called the California Borderland is unique. The bottom relief here is large-block, characterized by a combination of underwater hills - horsts and depressions - grabens, the depths of which reach 2500 m. The nature of the borderland relief is similar to the relief of the adjacent land area. It is believed that this is a highly fragmented part of the continental shelf, submerged to different depths.
The underwater margin of Central and South America is distinguished by a very narrow shelf only a few kilometers wide. Over a long distance, the role of the continental slope here is played by the continental side of the deep-sea trenches. The continental foot is practically not expressed.
A significant part of the continental shelf of Antarctica is blocked by ice shelves. The continental slope here is distinguished by its large width and dissected 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 are most fully expressed compared to other oceans. This is a natural combination of basins of marginal seas, island arcs and deep-sea trenches.
In the Western Pacific (Asian-Australian) sector, a number of transitional regions 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 Indonesia-Philippine region is complex, including the South China Sea, the 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, basins and trenches 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. Leontyev identified this area as a special type of transition zone - Vityazevsky. A feature of this area is the presence of a deep-sea 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 only the 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 transition zones of the Pacific Ocean are areas of the most significant vertical division of the earth's crust on Earth: the elevation of the Mariana Islands above the bottom of the trench of the same name is 11,500 m, and the South American Andes above the Peruvian-Chilean trench is 14,750 m.
Mid-ocean ridges (rises). They occupy 11% of the area of the Pacific Ocean and are represented by the South Pacific and East Pacific rises. The mid-ocean ridges of the Pacific Ocean differ in their structure and location from similar structures in the Atlantic and Indian Oceans. They do not occupy a central position and are significantly shifted to the east and southeast. This asymmetry of the modern 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-ocean rises of the Pacific Ocean also has its own characteristics. These structures are characterized by a domed profile, significant width (up to 2000 km), an intermittent strip of axial rift valleys with extensive participation in the formation of the relief of transverse fault zones. Subparallel transform faults cut the East Pacific Rise into separate blocks, shifted relative to each other. The entire uplift consists of a series of gentle domes, with the spreading center confined to the middle part of the dome, at approximately equal distances from the faults that bound it to the north and south. Each of these domes is also cut by en-echelon 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 uplift, but also extend far out onto 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 ridge, high heat flow values, 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-ocean rises 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 region, 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 elevations of the bottom relief in the axial part of the East Pacific Rise are everywhere about 2500-3000 m, but at some elevations they decrease to 1000-1500 m. The foot of the slopes is clearly traced along an isobath of 4000 m, and the bottom depths in the framing basins reach 5000-6000 m At the highest parts of the uplift there are islands. Easter and the Galapagos Islands. Thus, the amplitude of uplift above the surrounding basins is generally quite large.
The South Pacific uplift, separated from the East Pacific by the Eltanin fault, is very similar to it in its structure. The length of the Eastern uplift is 7600 km, the Southern uplift is 4100 km.
ocean bed
It occupies 65.5% of the total area of the Pacific Ocean. Mid-ocean rises divide it into two parts, differing not only in their size, but also in the characteristics of the bottom topography. The eastern (more precisely, southeastern) part, which occupies 1/5 of the ocean floor, is shallower and less complexly built in comparison with the vast western part.
A large proportion of the eastern sector is occupied by morphostructures that have a direct connection with the East Pacific Rise. Here are its lateral branches - the Galapagos and Chilean uplifts. The large blocky ridges of Tehuantepec, Coconut, Carnegie, Nosca, and Sala y Gomez are confined to zones of transform faults cutting the East Pacific Rise. Underwater ridges divide the eastern part of the ocean floor into a number of basins: Guatemala (4199 m), Panama (4233 m), Peruvian (5660 m), Chilean (5021 m). In the extreme southeastern part of the ocean is the Bellingshausen Basin (6063 m).
The vast western part of the Pacific Ocean floor is characterized by significant structural complexity and a variety of relief forms. Almost all morphological types of underwater bed rises are located here: arched shafts, block mountains, volcanic ridges, marginal rises, individual mountains (guyots).
The arched uplifts of the bottom are wide (several hundred kilometers) linearly oriented swellings of the basaltic crust with an excess of 1.5 to 4 km over the adjacent basins. Each of them is like a giant shaft, cut by faults into a number of blocks. Usually, entire volcanic ridges are confined to the central arched and sometimes to the flank zones of these uplifts. Thus, the largest Hawaiian swell is complicated by a volcanic ridge, some of the volcanoes are active. The surface peaks of the ridge form the Hawaiian Islands. The biggest one is o. Hawaii is a volcanic massif of several fused shield basalt volcanoes. The largest of them, Mauna Kea (4210 m), makes Hawaii the highest of the oceanic islands of the World Ocean. In a northwesterly direction, the size and height of the islands of 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 is the next one, the largest in length (about 11 thousand km), starting with the Cartographer Mountains, which then turn into the Marcus Necker Mountains (Midpacific), giving way to the underwater ridge of the Line Islands and then turning into the base of the Tuamotu Islands. The underwater continuation of this rise can be traced further east up to the East Pacific Rise, where the island is located at the place of their intersection. 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, and Samoa. Probably, the ridge of the southern islands of Cook and Tubu continues this mountain system. The fourth arc begins with the uplift of the North Caroline Islands, turning into the Kapingamarangi submarine swell. The last (southernmost) arc also consists of two links - the South Caroline Islands and the Eauriapic submarine swell. Most of the islands mentioned, which mark arched underwater shafts on the surface of the ocean, are coral, with the exception of the volcanic islands of the eastern part of the Hawaiian ridge, the Samoa Islands, etc. There is an idea (G. Menard, 1966) that many underwater rises of the central part of the Pacific Ocean - relics of the mid-ocean ridge that existed here in the Cretaceous period (called the Darwin Rise), which underwent severe tectonic destruction in the Paleogene. This uplift extended from the Cartographer Mountains to the Tuamotu Islands.
Block ridges are often accompanied by faults that are not associated with mid-ocean rises. In the northern part of the ocean, they are confined to submeridional fault zones south of the Aleutian Trench, along which the North-Western Ridge (Imperial) is located. Block ridges accompany a large fault zone in the Philippine Sea basin. Systems of faults and block ridges have been identified in many basins of the Pacific Ocean.
Various uplifts of the Pacific Ocean floor, together with mid-ocean ridges, form a kind of orographic framework of the bottom and separate oceanic basins from each other.
The largest basins in the west-central part of the ocean are: Northwestern (6671 m), Northeastern (7168 m), Philippine (7759 m), East Mariana (6440 m), Central (6478 m), West Carolina ( 5798 m), East Carolina (6920 m), Melanesian (5340 m), South Fiji (5545 m), South (6600 m), etc. The bottoms of the Pacific Ocean basins are characterized by low thickness of bottom sediments, and therefore flat abyssal plains are very limited in distribution (the Bellingshausen Basin due to the abundant supply of terrigenous sedimentary material carried from the Antarctic continent by icebergs, the North-Eastern Basin and a number of other areas). The transport of material into other basins is “intercepted” by deep-sea trenches, and therefore they are dominated by the topography of hilly abyssal plains.
The Pacific Ocean bed is characterized by separately located guyots - underwater mountains with flat tops, at depths of 2000-2500 m. On many of them, coral structures arose and atolls formed. The guyots, as well as the large thickness of dead coralline limestones on the atolls, indicate significant subsidence of the earth's crust within the Pacific Ocean floor during the Cenozoic.
The Pacific Ocean is the only one whose bed is almost entirely within the oceanic lithospheric plates (Pacific and small - Nazca, Cocos) with a surface at a depth of an average of 5500 m.
Bottom sediments
Bottom sediments of the Pacific Ocean are extremely diverse. In the marginal parts of the ocean on the continental shelf and slope, in marginal seas and deep-sea trenches, and in some places on the ocean floor, terrigenous sediments are developed. They cover more than 10% of the Pacific Ocean floor. Terrigenous iceberg deposits form a strip near Antarctica with a width of 200 to 1000 km, reaching 60° S. w.
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 to 60° S. w. In the Northern Hemisphere, their development is limited to the top surfaces of ridges and other elevations, where bottom foraminifera predominate in the composition of these silts. Pteropod deposits are common in the Coral Sea. Coral sediments are located on shelves and continental slopes within the equatorial-tropical zone of the southwestern part of the ocean and occupy less than 1% of the ocean floor area. Shelly shells, consisting mainly of bivalve shells and their fragments, are found on all shelves except 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 volcanogenic sediments are observed. An important distinctive feature of the bottom sediments of the Pacific Ocean is the widespread occurrence of deep-sea 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.
Bottom mineral resources
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 m2 (on average 7.3-7.8 kg/m2). Experts predict a bright future for these ores, arguing that their mass production can be 5-10 times cheaper than obtaining similar ores on land.
The total reserves of ferromanganese nodules at the bottom of the Pacific Ocean are estimated at 17 thousand billion tons. The USA and Japan are conducting pilot industrial development of nodules.
Other minerals in the form of nodules include phosphorite and barite.
Industrial reserves of phosphorites have been found near the California coast, in the shelf parts of the Japanese island arc, off the coast of Peru and Chile, near New Zealand, and in California. Phosphorites are mined from depths of 80-350 m. There are large reserves of this raw material in the open part of the Pacific Ocean within underwater rises. Baryte nodules were discovered in the Sea of Japan.
Placer deposits of metal-bearing minerals are currently important: rutile (titanium ore), zircon (zirconium ore), monazite (thorium ore), etc.
Australia occupies a leading place in their production; along its eastern coast, placers stretch for 1.5 thousand km. Coastal-sea placers of cassiterite concentrate (tin ore) are located on the Pacific coast of mainland and island Southeast Asia. There are significant placers of cassiterite off the coast of Australia.
Titanium-magnetite and magnetite placers are being developed near the island. Honshu in Japan, Indonesia, the Philippines, the USA (near Alaska), in Russia (near Iturup Island). Gold-bearing sands are known off the west 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 hydrotherms (“black smokers”) have been identified - outlets of hot (up to 300-400°C) juvenile waters with a high content of various compounds. Polymetallic ore deposits are being formed here.
Among the non-metallic raw materials located in the shelf zone, glauconite, pyrite, dolomite, building materials - gravel, sand, clay, limestone-shell rock, etc. are of interest. Offshore deposits of gas and coal are of greatest importance.
Oil and gas shows have been discovered 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, and Russia (in the area of Sakhalin Island). The development of oil and gas resources on the Chinese shelf is promising. The Bering, Okhotsk and Japanese seas are considered promising for Russia.
In some areas of the Pacific shelf there are coal-bearing strata. Coal production from the subsoil 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.