Pacific data

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Pacific Ocean

Pacific Ocean

The largest ocean in the world. Located between Asia, Oceania, North America, South America and Antarctica. It is bounded by the Bering Strait and the Arctic Ocean in the north, south to Antarctica, connected with the Atlantic Ocean and the Indian Ocean, and surrounds the Antarctic continent. It is bounded by the Atlantic Ocean in the southeast, from Cape Horn (69 55' W) at the southern tip of South America to Antarctic Peninsula (6 1 12' W), and from the northern end of Malacca Strait in the southwest along the southern banks of Sumatra Island, Java Island and Nusa Tenggara Islands to Buji in the southern bank of New Guinea. It passes through the line between Torres Strait and Cape York, Australia, and the meridian and Indian Ocean boundary from the southeast corner of Tasmania to the Antarctic continent (East longitude 146 5 1'). The name "Pacific" comes from 15 19, when the fleet led by Portuguese Magellan crossed the rough strait of magellan and entered a new ocean. During the dozens of days' voyage to the Philippine Islands, the sea was calm and the weather was fine. The crew called the new ocean the sea of peace and translated it into the Pacific Ocean in Chinese.

The outline of the Pacific Ocean is approximately elliptical. It starts from the Bering Strait in the north and reaches the Ross Ice Barrier on the northern edge of the Antarctic continent in the south, with the north-south latitude 135 degrees and the north-south maximum length 15900 kilometers. It starts from Panama in South America in the east and reaches the Malay Peninsula in Asia in the west. The east-west longitude span is 180 degrees, and the east-west maximum width is 1.99 thousand kilometers. It covers an area of 65,438+79 million square kilometers, accounting for 49.4% of the world's ocean area, exceeding 1/3 of the earth's surface area and larger than the total land area of the earth 1/5, making it the largest ocean in the world. The average depth of the Pacific Ocean (including marginal seas) is about 4,000 meters, which is more than 300 meters deeper than the average depth of the world's oceans. In the Pacific Ocean, 85.7% of the seabed is over 3,000 meters deep, and more than 50% is over 5,000 meters deep. There are 33 trenches with a water depth of more than 6,000 meters in the world's oceans and 26 in the Pacific Ocean, among which all deep-sea trenches with a water depth of more than 65,438+100000 meters are in the Pacific Ocean. The total volume of seawater in the Pacific Ocean exceeds 700 million cubic kilometers, accounting for about 53% of the total ocean water in the world, making it the largest ocean.

Map: Pacific Ocean

There are many islands in the Pacific Ocean, the size of which exceeds 10000, which is the largest among several oceans in the world. The total area of islands is 4.4 million square kilometers, accounting for 45% of the total area of islands in the world's oceans. Most of the islands are located in the central and western part of the ocean, among which New Guinea (Irian Island) is the largest island in the Pacific Ocean, and its area is the second largest island in the world after Greenland. Rivers flowing into the Pacific Ocean are mainly distributed in the eastern part of the Asian continent, such as Heilongjiang, Yellow River, Yangtze River and Mekong River. In North and South America in the east of the ocean, because the mountains are almost close to the coast, there are no big rivers and rivers flowing into the Pacific Ocean. Therefore, the amount of water injected into the Pacific Ocean by rivers is relatively small, accounting for only 1/7 of the total amount of water injected into the ocean by rivers in the world.

Submarine topography The Pacific Ocean is an ancient ocean. The modern Pacific Ocean is the product of the ancient transoceanic (ancient Pacific Ocean) contraction in the early Mesozoic. Modern ocean floor geomorphology is formed in the long-term interaction between ocean floor plate and continental plate and the complex geological structural activities such as submarine expansion movement. Submarine topography can be divided into three tectonic topographic units: continental margin zone, mid-ocean ridge and submarine mountains and ocean basin.

The continental margin includes continental shelf, continental slope, island arc, deep trench and marginal basin, accounting for about 24% of the total area of the Pacific Ocean. The continental shelf area is about 9.38 million square kilometers, accounting for 5.2% of the total area of the Pacific Ocean and 30% of the world's marine continental shelf area, mainly distributed in the western, southwestern and northern parts of the Pacific Ocean. The widest point of the western continental shelf is 750 kilometers, and the Yellow Sea in China is almost entirely on the continental shelf. The continental shelf in the eastern part of the ocean is narrow and discontinuous, with a width of only 18 ~ 20km in North America and 70km at its widest point in South America. The average slope of the Pacific continental slope is 5 20', which is the largest among the four oceans in the world. There are submarine canyons, cliffs, cliffs and terraces on the slope. At the junction of the western Pacific continental slope and ocean basin, there are a series of famous island arcs and trenches. Generally, the island arc is in an arc protruding to the ocean, and it consists of Aleutian Islands, Thousand Islands, Japanese Islands, Ryukyu Islands, Mariana Islands, Philippine Islands, Solomon Islands, New hebrides, tonga islands and Kemadek Islands from north to south, with a length of 9,520 kilometers. A series of trenches are associated with the outer side of the island arc, among which the deep-sea trenches with a depth of more than 654.38+00000 meters include Qiandao-Kamchatka trench (10542m), Japan trench (10554m), Philippine trench (10497m) and Tonga trench. On the east coast of the ocean, the continental mountain system of North and South America is close to the coast. Except for some islands and winding coasts in the fjords south and north of 40 north latitude, most of the coasts are straight, and there are no island arcs and marginal basins. Trenches include Alaska Trench in the north, Central American Trench (6662m in Guatemala Trench) and peru-chile trench in the south (8055m in Atacama Trench). There are a series of wide marginal basins in the island arc of the western Pacific Ocean, which form the marginal seas of the western Pacific Ocean, mainly including Bering Sea, Okhotsk Sea, Japan Sea, Yellow Sea, East China Sea, South China Sea, Java Sea, Sulawesi Sea and Coral Sea. Island arcs and trenches in the western Pacific Ocean are the products of the collision between the Pacific plate and the Eurasian plate, and are the areas with the strongest crustal movement, where earthquakes and volcanic activities often occur. Therefore, the boundary zone around the ocean plate and the continental plate has become the concentrated zone of earthquakes and volcanoes in the Pacific Rim region, where about 90% of earthquakes and 85% of active volcanoes on the earth are distributed.

The Central Pacific Ridge (also known as seamount) is a prominent seabed topographic structure, which is located in the eastern part of the ocean. It starts from the Antarctic-Indian Ocean Ridge at 60 south latitude, turns north to the east near the west longitude 130, and extends north roughly parallel to the American coast, reaching gulf of alaska, with a length of about 15000 km and a width of about 2000-4000 km, accounting for about1/kloc-0 of the total area of the Pacific Ocean. The central rift in the mid-ocean ridge is not well developed, and its height is relatively low, generally 2 ~ 3 kilometers. It is higher in the south of the ocean, and lower as it goes north. It is almost similar to the Aleutian Basin, submerged under the North American continent. The mid-ocean ridge is cut by a series of roughly east-west fault zones, the distance between two adjacent zones is about 900 ~ 2,200 km, and the fault zone extends more than 2,000 km in the east-west direction, with a width of about 1000 ~ 200 km, which is a narrow groove in landform. From north to south, the fault zones are Mendocino fault zone (40 40' N), Murray fault zone (38 N), Molokai fault zone (about 26 N), Clipperton fault zone (1130' n), Galapagos fault zone (near the equator) and East fault zone (27 S). The mid-Pacific ridge is an integral part of the mid-ocean ridge in the world, and its southern end is connected with the Antarctic-Indian Ocean Rise.

There are also a series of northwest-southeast submarine mountains in the middle of the Pacific Ocean, which is one of the most magnificent landforms in the Pacific Ocean. It starts from kamchatka peninsula in the north, passes through Dihai Mountain, Hawaiian Islands and Lane Islands, and reaches Tuamotu Islands in the south, stretching for more than 10000 kilometers. It is a volcanic group formed by the stress of the Pacific plate and the recent fault on the basalt basement, which triggered a large number of basalts to erupt along the fault. Unlike mid-ocean ridges, most of these submarine mountains are composed of submarine volcanoes without seismic activity, and a few are active volcanoes, such as those in the Northern Mariana Islands, and a few are formed by the sinking of some coral islands in the depths of the ocean. They have a relatively flat mountain, called the undersea Pingdingshan. Some towering seamounts protrude from the sea and become islands, such as the Hawaiian Islands and the Lane Islands.

A series of submarine mountains divide the Pacific basin into four sub-deep sea basins, with the Emperor-Hawaiian Mountains (ocean ridges) as the boundary and the Northeast Pacific basin in the east, with a water depth of 4000-6000 meters and a maximum depth of 7 168 meters. To the west is the Northwest Pacific Basin, with an average depth of 5,700 meters and a maximum depth of 6,224 meters. The Central Pacific Basin is located between submarine mountains, Lane Islands and Marshall Islands, with a water depth of 5000-5500 meters and a maximum water depth of 6370 meters. South of the Central Pacific Basin and north of the Antarctic-Pacific Ridge is the Southwest Pacific Basin, with a water depth of 4500-6000m and a maximum water depth of 8581m.. There are brown clay, biogenic sediments, turbidite sediments and volcanic sediments in the vast and flat deep-sea basin of the Pacific Ocean, among which biogenic sediments and brown clay are the most widely distributed, occupying almost the whole ocean basin.

Climate and ocean currents, solar radiation and atmospheric circulation are the dominant factors that determine the climate in the Pacific Ocean. In addition, the Asian continent and ocean currents are also influencing factors. The atmospheric circulation in the Pacific Ocean is controlled by two high-pressure regions and three low-pressure regions distributed in the latitudinal direction.

Near the equator is a low pressure area, with strong solar radiation and high temperature all year round, and the annual average temperature is above 26℃, which is a high temperature area of the ocean. At the same time, due to the high temperature, the air is often in an unstable state, with convective precipitation, and the annual precipitation is more than 2000 mm, which has become a rainy zone in the ocean. Between 5 and 20 latitudes, tropical storms often form and move.

There is a strong and stable subtropical high belt between 30 and 35 latitude, and the center of high pressure is in the east of the ocean. In the high-pressure control area, the air flow sinks mainly, the precipitation is scarce, and evaporation is vigorous, which forms the dry area of the Pacific Ocean and the main supply area of water vapor in the air, and is also the area with the highest salinity on the ocean surface. The air flow sinking from the subtropical high pressure area to the equatorial low pressure area is called the trade wind area. The trade wind zone is the most famous planetary wind zone on the earth, with stable wind direction and strong wind force, which is an important driving force for the formation and maintenance of low-latitude ocean surface current. The airflow sinking from the subtropical high pressure area to the subtropical low pressure area is called westerlies. The westerly belt is also a planetary wind belt in the ocean. Winter is strong, and the gale frequency reaches 25% ~ 35%, which becomes the driving force for the surface water of mid-latitude ocean to flow from west to east, especially in the southern hemisphere. Because the South Pacific Ocean is connected with the Indian Ocean, it broadens the sea area. Influenced by the Antarctic cold source, the westerly belt becomes a wind belt with stable wind direction and strong wind force. In addition, the cyclone activity in the polar front belt is frequent, often exceeding 18 m/s.

Near 60 north latitude is a sub-polar low pressure belt, which is located in the Aleutian Islands, also known as the Aleutian low pressure. Winter is low and summer is weak. It attracts the surrounding air to rotate counterclockwise, and then blows the surface water of the surrounding ocean to form an anticlockwise circulation system. The Antarctic depression extends near the South Pole. Like the global pressure belt and wind belt, the pressure belt and wind belt in the Pacific move north and south within one year, and their intensity increases and decreases, which will affect the corresponding changes of ocean currents, water temperature and salinity in the Pacific Ocean. In the tropical, subtropical and temperate regions of the western Pacific Ocean, due to the thermal difference between the Asian continent and the Pacific Ocean and the seasonal movement of the planetary wind system, a unique monsoon region in the world has been formed. Every summer, warm and humid air from the ocean flows to the land, and dry and cold air from the land blows to the ocean in winter. This regional monsoon circulation disturbs the zonal distribution of marine climate, and has a great impact on ocean current, water temperature, precipitation, evaporation, salinity and marine life in the western Pacific Ocean.

A large-scale anticyclonic circulation system centered on the subtropical high in the south and north of the Pacific Ocean is formed, which is caused by the stable prevailing wind belt and formed by geostrophic deflection, continental contour and island distribution. The North Pacific circulation consists of the North Equatorial Warm Current, the Japanese Warm Current (Kuroshio), the North Pacific Warm Current and the California Cold Current. The South Pacific circulation consists of the South Equatorial Warm Current, the East Australian Warm Current and the west wind drift and Peru Cold Current. There is an equatorial countercurrent from west to east between the two circulation systems. To the north of 45 north latitude in the North Pacific, there is a cyclone circulation system centered on Aleutian low pressure, which consists of Alaska warm current, Thousand Island cold current (tide-loving) and North Pacific warm current. In the sea area south of 40 south latitude of the South Pacific, there is no continental barrier, and the Antarctic circumpolar circulation (west wind drift) is formed around the Antarctic continent, and then the polar easterly drift is formed under the action of the southern polar easterly wind. The Japanese warm current (Kuroshio) in the North Pacific Ocean is the most powerful ocean current in the Pacific Ocean and the second largest warm current in the world after the Mexican warm current. The transformation from the northern equatorial warm current to the east of Luzon Island has the characteristics of strong velocity, large discharge (equivalent to 20 times of the total flow of all rivers in the world), narrow discharge range, deep extension, high temperature and high salinity. Because the water is dark blue and looks like black from a distance, it is named Kuroshio. The west wind drift in the North Pacific Ocean, also known as the North Pacific Warm Current, is an important member of the low-latitude and high-latitude ocean current circulation system. West wind drift in the South Pacific is the surface part of Antarctic circumpolar current, but at 35 ~ 65 south latitude, it extends from the sea surface to the seabed, becoming a broad, deep and powerful wind drift. It flows eastward, one passes through the Drake Strait, and the other turns from 45 south latitude to north, becoming a cold current in Peru. The Peruvian cold current flows northward along the west coast of South America to the Cologne Islands (Galapagos Islands) near the equator, with a total length of 4,600 kilometers. This is the longest and strongest cold current in the world. Its width is 180 kilometers near the coast of Chile, but it becomes 450 kilometers on the coast of Peru, with a small flow of about 7.7 kilometers a day and night. The water temperature is 15 ~ 17℃, which is 7 ~ 10℃ lower than the adjacent sea area. At the same time, rip flow is generated by the prevailing southeast wind, which makes the middle-level cold water with a depth of about 100 meters rise to the sea surface, and the upwelling brings a lot of nitrate and phosphate nutrients to the sea surface, which is beneficial to plankton reproduction. However, when the El Ni? o warm current southward in the equatorial waters of the East Pacific Ocean extends southward along the coast of Ecuador to 5 or even12 south latitude, it mixes with the cold current seawater of Peru, which raises the water temperature of the cold current and inhibits the flooding of cold water, resulting in the death of a large number of cold-water organisms along the coast, including plankton and fish, and then fish-eating birds, which brings disaster to fishery production. This phenomenon of sea water warming is called El Nino phenomenon, which has attracted worldwide attention.

Water temperature and salinity The characteristics of the surface water temperature in the Pacific Ocean are mainly affected by the ocean surface temperature. The distribution of water temperature shows the basic law of extending along latitude and gradually decreasing with the increase of latitude. The highest temperature appears in the equatorial region, especially in the west, and the average water temperature is 27 ~ 29℃. The water temperature is 25 ~ 26℃ between north and south latitudes 10 ~ 20; Between 40 and 50 degrees north and south latitude, the water temperature drops to 5 ~ 10℃. The water temperature at the edge of the Antarctic continent is about 0℃. The water temperature isoline is basically zonal in latitude distribution, especially in the southern hemisphere ocean. However, due to the difference of ocean currents between the east and west sides of the ocean and the influence of monsoon and coastal upwelling, the water temperature in the west of the low latitude Pacific Ocean is about 4 ~ 8℃ higher than that in the east. The water temperature in the western part of the mid-high latitude ocean in the northern hemisphere is 8 ~ 65438 02℃ lower than that in the eastern part. In the hottest month of summer (August), the surface water temperature in the North Pacific Ocean is above 0℃, and the highest water temperature appears in the waters near Central America, reaching above 29℃ and 26 ~ 28℃ near the equator. The lowest temperature near the Kuril Islands is 0 ~ 2℃. The 0℃ isotherm of water temperature is located in the ocean at 55 north latitude and 66 ~ 67 south latitude respectively. The Pacific Ocean at low latitudes is larger than other oceans, so the water temperature is higher. The area with annual water temperature higher than 25℃ accounts for 35% of the total area of the Pacific Ocean, and the area with annual water temperature higher than 20℃ accounts for 53%. The annual average surface water temperature of the Pacific Ocean is 19.37℃, which is higher than that of other oceans and is the warmest ocean in the world. Due to the difference in land area between the northern and southern hemispheres, the difference in the opening degree of the waters at the northern and southern ends of the ocean and the difference in the amount of cold water exchanged between the two poles, the water temperature in the South and North Pacific is not equal, and the surface water temperature in the North Pacific is higher than that in the South Pacific 1 ~ 2℃.

The salinity of ocean seawater mainly depends on the comparison between atmospheric precipitation and ocean surface evaporation. When precipitation exceeds evaporation, seawater desalinates and salinity decreases, whereas salinity increases. The equatorial region of the Pacific Ocean is rainy, with annual precipitation of 2000 ~ 3000mm, which is greater than evaporation, so the salinity of seawater is not too high, generally 34 ~ 34.5; The subtropical zone is dry, with precipitation less than evaporation, and the highest salinity is above 35.5. Precipitation in temperate zone is more than evaporation, and salinity is reduced to below 34; Due to the decrease of evaporation and the influence of melting ice in cold regions, the salinity in warm seasons is generally around 30. The average salinity of the Pacific Ocean is 35.

Marine Resources The Pacific Ocean is vast and rich in natural resources. The main resources that have been developed and utilized are aquatic products and mineral resources. There are many kinds of animals and plants in the Pacific Ocean, with nearly 654.38+million species, mainly living in the ocean surface, especially in the marginal zone. There are only 4% ~ 5% animals and plants in the waters below 2000m, 800 species in the waters below 5000m, 500 species in the waters below 6000m and 200 species in the waters below 7000m, reaching 65438 species. At the same time, the species of marine life decreases with the increase of latitude, but the distribution density of various animals and plants is higher at high latitude than at low latitude, and there are more dominant species at high latitude. There are a lot of phytoplankton and zooplankton on the ocean surface. Among the benthic organisms in offshore waters, there are hornworts and laminaria in temperate zone (mainly kelp), and brown algae, green algae and many kinds of fine algae in tropical zone. There are mangroves along the coast. Numerous algae provide enough feed for coastal animals, breed all kinds of mollusks, mollusks, crustaceans and echinoderms, and corals, and produce a large number of fish and crabs. It is the habitat of seabirds in islands and coastal areas. There are many animals in the ocean, such as whales, seals, dolphins, sea bears, sea dogs, sea otters and so on.

Since1mid-1960s, the fishery output of the Pacific Ocean has been the highest in the world. 1980 produced 35.45 million tons, accounting for more than half of the world's total catch (64.576 million tons). There are mainly two fishing grounds: one is the northwest Pacific fishing ground; The other is the southeast Pacific fishing ground. The fishing grounds in the Northwest Pacific Ocean include the Bering Sea, the Sea of Okhotsk, the Sea of Japan, the Yellow Sea, the East China Sea and a part of the Taiwan Province Strait. The continental shelf area of the fishing ground is 210.9 million square kilometers, the seawater is shallow, the sunlight can penetrate into the seabed, many rivers bring a lot of inorganic salts, and the cold and warm currents bring cold and warm plankton, which provides suitable conditions for plankton nourishment and fish growth and becomes one of the major fishing grounds in the world. 1980 fishing output18.78 million tons, ranking first in the world's major fishing areas, among which Hokkaido fishing ground in Japan mainly produces herring, salmon, trout and other fish. The Bering Sea and the Sea of Okhotsk mainly catch marine animals, among which whaling is the most. The coast of kamchatka peninsula is the largest crab farm in the world. The Zhoushan Islands along the coast of China mainly catch large yellow croaker, small yellow croaker, hairtail, pomfret, eel and squid. Fishing grounds in the Southeast Pacific include those in Peru, Chile and Ecuador, with a narrow continental shelf of only 1.6 million square kilometers. However, due to the strong environmental conditions such as cold current and coastal upwelling in Peru, inorganic salts are also quite rich, which is suitable for plankton reproduction and rich in fish, making it an important fishing ground. Among them, anchovies are mainly produced in Peruvian waters, and Peru is in a blank? Testicular j 2 Is it embarrassing? The output is 500 ~100000 tons. In addition, the northeast, central and eastern China and the southwest Pacific also produce a certain number of fish every year.

Japanese kelp fishing boat

The exploration and exploitation of mineral resources in the Pacific Ocean are mainly concentrated in offshore shallow waters, the most important of which is oil and natural gas on the continental shelf. The main oil-producing areas are Alaska, California, Cook Bay, the continental shelf of western Japan, Southeast Asia, the west coast of South America and the continental shelf of China. The proven oil reserves and production in the Pacific Ocean still lag behind those in the Atlantic Ocean and the Indian Ocean. There are also coal mines on the seabed near the ocean, which have been mined by Japan and Chile. Other minerals include gold, platinum, diamond, rutile, zircon, ilmenite, tin, iron and manganese. Gold and platinum sands with economic significance are mainly distributed in the east coast of the Pacific Ocean, Bering Sea and Alaska from Oregon to California. Tin mines are mainly produced in the coastal areas of Southeast Asian countries. India and Australia have the most abundant reserves of zircon, rutile and ilmenite. In recent years, a large number of manganese nodules and manganese crusts have been found in the basin of the Pacific Ocean with a water depth of 4000-5000 meters. Their distribution range, reserves and grade are the highest in all oceans, mainly distributed in the range of 6-20 north latitude, 65,438+065,438+000-65,438+080 west longitude. The estimated reserves are 6543.8+700 million tons.

China Nanhai drilling platform

Transportation and Communication The Pacific Ocean has a vast territory and numerous harbors, and there are many important air and sea routes connecting Asia, Oceania, North America and South America. The Pacific Ocean is second only to the Atlantic Ocean in world shipping, with 1/6 of the total number of seaports in the world, 3/ 10 of freight turnover and 1/4 of cargo throughput. The bulk goods transported by sea are oil, ore, grain, etc. The main shipping routes are East Asia-North America West Coast, East Asia-Caribbean Sea, North America East Coast, East Asia West Coast-South America, East Asia-Australia, New Zealand-North America and East Asia Coastal Routes. There are many ports along the Pacific coast, mainly Vladivostok, Busan, Dalian, Tianjin, Shanghai, Guangzhou, Hong Kong, Haiphong, Singapore, Jakarta, Tokyo, Yokohama, Kobe, Osaka, Sydney, Wellington, Vancouver, Seattle, San Francisco, Los Angeles, Panama City, Guayaquil and other ports. Hawaii, Midway, Guam, Western Samoa and Fiji Islands in the Pacific Ocean are the relay stations of air and sea routes, which are of great economic and strategic significance. Submarine cables were laid in the Pacific Ocean from 1902, and now there are submarine cables from Vancouver, Canada to Sydney, Australia, from San Francisco to the Philippines, from Japan to Indonesia, from Hong Kong to the Philippines, Vietnam and coastal countries in South America. In recent years, artificial communication satellites have been used for communication over the Pacific Ocean.

Corner of Pier 8, Qingdao Port, China

Scenery of Sydney Harbour, Australia

Most of the areas around the Pacific Ocean are developing countries, and the long-term economic development level in the past was low. The tall and long Cordillera mountain system on the American continent on the east coast of the Pacific weakens or restricts the connection between the ocean and the whole American continent, while economically developed countries such as the United States and Canada have a long Pacific coastline, but their main economic centers are far away from the Pacific Ocean. The economic centers of some economically developed countries in Latin America rarely face the Pacific Ocean. As a result, the freight volume of the Pacific Ocean is less than half that of the Atlantic Ocean. In recent years, the economy in the Pacific region has developed rapidly. With the continuous improvement of economic strength and status, the economic ties between countries in the Pacific region and other parts of the world are getting closer and closer, and the transportation and communication in the Pacific region will be further developed.