The area of the Pacific Ocean accounts for about one third of the total area of the earth, and the width of the north-south distance is 15500 km. The southernmost part of the Pacific Ocean is close to Antarctica, and the northernmost part can extend to the Bering Strait, with a latitude of 135, making it the largest ocean in the world. The major rivers in the Pacific Ocean are distributed in China and Southeast Asia.
Comprehensive description
The longest distance from east to west in the Pacific Ocean is 21.300km, and its volume is about 71.441.000km2, excluding the ocean area of 6961.8900km3. In the Pacific Ocean, the average depth of the ocean is 4187.8m, and the maximum depth is11034m.
At the northern end of the Pacific Ocean, bounded by the Bering Strait, the width of Hailing Strait is only 102 km. The southeast is connected with the Atlantic Ocean through Tierra del Fuego in North America and Drake Strait in Antarctica. From Sumatra Island to Java Island, then to Timor Island, then to Cape Delhi, Australia, then to bass strait in southern Australia, and finally to the Antarctic continent via Tasmania, it is the dividing line between the southwest Pacific Ocean and the Indian Ocean.
Due to the special geographical location of the Pacific Ocean and the layout of the main mountain systems of the earth, the water injected into the Pacific Ocean accounts for only one seventh of the total water injected into the ocean by rivers in the world.
The Pacific Ocean reaches the North Pole in the north, the South Pole in the south, Asia and Australia in the west and North and South America in the east. Excluding the adjacent waters, it covers an area of about165.2 million square kilometers, making it the largest ocean in the world.
People often habitually divide the Pacific Ocean into four parts: east, south, west and north. There are many seas in the western Pacific, from north to south: Bering Sea, Sea of Okhotsk, Sea of Japan, Yellow Sea, East China Sea and South China Sea. Heilongjiang, Yellow River, Yangtze River, Pearl River and Mekong River all flow into the Pacific Ocean through the sea. The ocean floor to the east of 150 W is smoother than that to the west. From the Aleutian Ridge in the Northwest Pacific to the Thousand Islands, Ogasawara Islands, Mariana, Yapu and Palau; Extending eastward from Palau to Bismarck, Solomon Islands and Santa Cruz; Finally, from Samoa to Tonga, Kemadek, Chatham and mcquarrie. Because the Arctic continent is covered by glaciers all the year round, the water temperature in the North Pacific is higher than that in the South Pacific. The cold water generated near the Antarctic continent has the greatest influence on the vertical flow in the Pacific Ocean, which sinks near the extreme low and then spreads northward, gradually forming the bottom of the Pacific Ocean.
The Pacific basin can be divided into three regions.
East Zone: The Cordiller Mountains in the United States start from Alaska in the north and reach Tierra del Fuego in the south. Except for the northernmost and southernmost fjords and the islands along the California Gulf, the coast is straight and the continental shelf is narrow. Acapulco Trench in the north and peru-chile trench in the south.
Western District: Some parts of Asia have complex structures and tortuous coasts. There are prominent peninsulas on the eastern edge of the mainland and a series of island arcs off the coast, forming numerous marginal seas. From north to south, there are Bering Sea, Sea of Okhotsk, Sea of Japan, Yellow Sea, East China Sea and South China Sea. There are a series of trenches on the outer edge of the archipelago, including Kamchatka trench, Kuril Islands trench and Japan trench in the north, Dongjia trench and Kemadek trench in the south.
The region with the most stable crustal structure: The region with the most stable crustal structure in the Pacific Ocean is the vast basin in the middle of the ocean, and the seawater depth in this region is generally about 5000 meters.
The Pacific Ocean is the ocean with the largest number of islands in the world, and it is also a zone with frequent volcanoes and earthquakes. Because the Pacific Ocean spans several different climates, the distribution of ocean currents in the Pacific Ocean is also very special. Because of the great difference in climate, different wind belts have been formed.
islands
There are many islands in the Pacific Ocean, accounting for 45% of the total number of islands in the world. In the Pacific Ocean, there are 20,000 large and small islands, covering an area of about 4.4 million square kilometers. Islands in the Pacific Ocean can be divided into mainland islands and islands according to their causes, and mainland islands can be divided into volcanic islands and coral islands.
Most of the islands in the Pacific Ocean are located between the Tropic of Cancer and belong to the tropical rain forest or savanna climate. It is hot and rainy all year round, with an average annual temperature of 25℃ ~ 28℃, and the annual variation generally does not exceed 5℃. The annual precipitation is also relatively large, generally 2000 mm to 3000 mm, and in some places it will exceed 4000 mm. Due to the influence of the mainland, the monsoon climate in various regions of the western region is remarkable.
In the Pacific Ocean, except the South Island and the North Island of New Zealand, most of the islands are located in the middle of the Pacific Ocean. One of the characteristics of the islands in the Pacific Ocean is that they are surrounded by islands. Among the Pacific islands, new guinea is the largest island, with an area of 785,000 square kilometers, and the second largest island in the world after Greenland. The total population of the Pacific islands is 5.8 million, accounting for 23.3% of the total marine population. Three Pacific islands: Melanesia, south of the southwest equator, west of the 180 meridian, extending from northwest to southeast; Micronesia Island, north of the northwest equator, east longitude 180 degrees west, extending from west to east. Polynesia, located east of east longitude 180, between 30 and 30 north latitude, extends from northwest to southeast. These three islands are located between Asia, Australia and North America, and they are also connected with various oceans. In international transportation, the Pacific Ocean occupies an important position.
submarine topography
The seabed topography of the Pacific Ocean can be divided into three parts: central deep water area, marginal shallow water area and continental shelf. Deep-sea basins below 2000 meters account for about 87% of the total area, marginal parts between 200 meters and 2000 meters account for about 7.4%, and continental shelves within 200 meters account for about 5.6%. There is a vast continental shelf in the northern and western marginal waters, and the water depth in the deep water area in the middle is more than 5000 meters. The marginal shallow water area is more than 5000 meters deep and the basin area is small. At the bottom of the Pacific Ocean, there are a lot of volcanic piles. This constitutes the complex topography of the seabed.
Volcanoes and earthquakes
About 85% of active volcanoes and 80% of seismic belts in the world are mainly concentrated in the Pacific Ocean. The Cordillera Mountains on the east coast of the Pacific Ocean and the western edge of the Pacific Ocean are the most violent earthquake zones in the world, with frequent earthquakes. There are about 370 volcanoes here, which are called "Pacific Ring of Fire".
climate
The Pacific Ocean is mainly located in tropical and subtropical areas, so the climate now formed is mostly tropical and subtropical, and the temperature gradually decreases with the increase of latitude. The distribution and regional differences of climate in the Pacific Ocean are mainly caused by the influence of surface ocean currents and air currents in neighboring continents.
The North Pacific and the South Pacific are the coldest months, with the average temperature from the Tropic of Cancer to the polar regions ranging from 20℃ to 16℃, and the central Pacific region always keeps around 25℃, with relatively more annual precipitation. Tsunamis in the Pacific Ocean are very famous for their high lethality and destruction rate. In the transition zone and westerly zone where cold and warm air meet, there are often strong winds and waves. The northern Pacific Ocean is dominated by winter, while the southern Pacific Ocean is dominated by summer. In the middle of the ocean, it is relatively calm, especially in summer and winter, and it is suitable for sailing all year round.
wind belt
Because of the vast area of the Pacific Ocean and the uniform water body, it is beneficial to the formation of planetary wind system, especially in the South Pacific Ocean. The situation in the North Pacific is different, and the gap between the east and the west is obvious. The trade wind is located between the subtropical high center of the East Pacific and the equatorial windless area, with a latitude of 30-40. The mid-latitude area, westerly belt and extremely low easterly wind meet to form a sub-extreme low pressure belt. The temperature difference between the two wind belts is very large, and the front is very fierce in the extremely low easterly belt, especially in winter. In the western Pacific, typhoons often appear in summer and autumn on the ocean surface east of the Philippines, the South China Sea and the East China Sea of China. It is precisely because the ultra-low pressure center is formed under the conditions of high temperature and high humidity in summer and autumn that typhoons often appear.
In summer, the Asian continent is a low-pressure area, and the air flow in the North Pacific moves to the Asian continent, while in winter, it is just the opposite, thus forming a broad monsoon climate area. At different latitudes, the salinity of seawater is different. The salinity in the trade winds is lower than that in the equator, less than 34 near the equator, and the lowest in the northernmost part of the Pacific Ocean.
ocean current
Under the influence of the trade winds, the ocean current in the Pacific Ocean moves from east to west, forming a warm current between the north and south equator, and an opposite equatorial countercurrent will appear on the central axis between the north and south equator, flowing from the east coast of the Philippines to the Aral Sea of Ecuador. The North Equatorial Warm Current flows into the Sea of Japan through the Straits of Malacca. The North Equatorial Warm Current turns north near the Philippines and flows to the east of the Sea of Japan. This is the famous Kuroshio. The Kuroshio turns eastward near160 E, which is called the North Pacific Warm Current. The warm current of the North Pacific moved eastward, turned south on the west coast of North America, and was caught up by the California cold current. In this way, the North Pacific circulation is formed. The Bering Sea current flows southward, which is called Kamchatka Cold Current, and flows to the east of Honshu Island, Japan. It encountered a Kuroshio near 36 north latitude. After arriving in Solomon Islands, the South Equatorial Warm Current flows southward to become the East Australian Warm Current, turns eastward and is involved in west wind drift. It is divided into two branches in the west of South America and near 45 south latitude, and one branch enters the Atlantic Ocean eastward through the Drake Strait. The other branch turns to the north, that is, the Peruvian cold current, thus forming the familiar South Pacific circulation.
The Pacific Ocean is particularly rich in marine resources, including animals and plants, plankton, fish and mineral resources, which are richer than other oceans.
In the western Pacific, the Sea of Japan and the Sea of Okhotsk are both important fishing grounds in the world, mainly producing herring, cod, tuna and crabs. There are abundant manganese nodules on the seabed of the Pacific Ocean, and sea salt, bromine and magnesium can also be extracted from seawater. The Pacific continental shelf is one of the regions with the richest oil resources in the world. The Pacific Ocean is not backward, and the western Pacific Ocean has long had a high cultural level. However, people's understanding of the Pacific Ocean is very late. It was not until16th century that Europeans began to explore this ocean. At that time, all they sought was Australia, and they entered the Pacific Ocean. After that, Magellan sailed around the world and crossed the Pacific Ocean. After Magellan, many scientists continued to further investigate the Pacific Ocean, and these scientists made contact contributions to the understanding of the Pacific Ocean for future generations.
fishery
The fishing grounds in the shallow sea of the Pacific Ocean account for almost half of the total fishing grounds in the world, and the catch in the ocean also accounts for more than half of the world's catch. Zhoushan Islands in China, Peru, Japan, the United States and the northwest coast of Canada are all world-famous fishing grounds. In addition, the abnormal catch of marine animals also occupies an important position in the world.
mineral resources
The offshore continental shelf of the Pacific Ocean is particularly rich in oil, natural gas and coal resources, and the deep-sea basin is rich in manganese nodules, as well as placer tin, rutile, zirconium, titanium, iron and platinum. Therefore, the Pacific Ocean is a rare "land of geomantic omen" in the world.
shipping
The Pacific Ocean is an important hub of world transportation and is of great significance in international transportation. Many air and sea routes in the world pass through the Pacific Ocean. The Panama Canal to the east of the Pacific Ocean is the main route to the Atlantic Ocean, and the Malacca Strait to the southwest is an important passage to the Indian Ocean.
The shipping routes in the Pacific mainly include East Asia-North America west coast route, East Asia-Caribbean route, North America east coast route, East Asia-South America west coast route, East Asia-Australia, New Zealand route, Australia, New Zealand-North America east and west coast route and so on. There are many ports along the Pacific coast, which are also important stops for world shipping.
Geographically, the180th meridian running through the Pacific Ocean is called "International international date line". If the passing ships cross this line from west to east, the date will be reduced by one day; On the other hand, if it is from east to west, then the date plus one day.
marine cable
1902, Britain laid the first submarine cable in the Pacific Ocean. Three years later, the United States also laid cables in the Pacific Ocean. Nowadays, many countries have their own submarine cables, such as cables from the United States to the Philippines, Japan, Indonesia, Canada to Australia, Hong Kong to the Philippines, Vietnam and South American countries. With the development of science and technology, in recent years, countries have begun to use satellite systems for communication over the Pacific Ocean.