World Ocean- the main part of the hydrosphere, a continuous but not continuous water shell of the Earth, surrounding continents and islands and characterized by a common salt composition. The world's oceans are a heat regulator. The world's oceans have the richest food, mineral and energy resources. Although the World Ocean is a single whole, for the convenience of research, its individual parts are given different names: Pacific, Atlantic, Indian, Arctic and Southern oceans.
Ocean and atmosphere. The world's oceans, whose average depth is approx. 4 km, contains 1350 million km3 of water. The atmosphere, which envelops the entire Earth in a layer several hundred kilometers thick, with a much larger base than the World Ocean, can be considered as a “shell”. Both the ocean and the atmosphere are fluid environments in which life exists; their properties determine the habitat of organisms. The ocean determines the basic properties of the atmosphere and is a source of energy for many processes occurring in the atmosphere. The circulation of water in the ocean is influenced by winds, the Earth's rotation, and land barriers.
Ocean and climate. It is well known that the temperature regime and other climatic characteristics of the area at any latitude can change significantly in the direction from the ocean coast to the interior of the continent. Compared to land, the ocean warms more slowly in summer and cools more slowly in winter, smoothing out temperature fluctuations on the adjacent land.
Composition of sea water. The water in the ocean is salty. The salty taste is given by the 3.5% dissolved minerals it contains - mainly sodium and chlorine compounds - the main ingredients of table salt. The next most abundant is magnesium, followed by sulfur; All the usual metals are also present. Of the non-metallic components, calcium and silicon are especially important, since they are involved in the structure of the skeletons and shells of many marine animals. Due to the fact that the water in the ocean is constantly mixed by waves and currents, its composition is almost the same in all oceans.
Properties of sea water. The density of sea water (at a temperature of 20 ° C and a salinity of about 3.5%) is approximately 1.03, i.e., slightly higher than the density of fresh water (1.0). The density of water in the ocean varies with depth due to the pressure of the overlying layers, as well as depending on temperature and salinity. In the deepest parts of the ocean, waters tend to be saltier and colder. The densest masses of water in the ocean can remain at depth and maintain a low temperature for more than 1000 years.
Seawater is much less transparent to visible light than air, but more transparent than most other substances. The penetration of solar rays into the ocean to a depth of 700 m has been recorded. Radio waves penetrate into the water column only to a small depth, but sound waves can travel thousands of kilometers under water. The speed of sound in seawater varies, averaging 1500 m per second.
The surface of our planet is 71% covered by oceans, which make up 97% of the Earth's water. According to experts, only 5% of the ocean depths have been explored so far. The world's oceans are the main component of the planet's hydrosphere, influencing weather and climate conditions. It is home to about 2 million species of animals, the vast majority of which have not yet been studied.
All bodies of water that are part of the World have a significant impact on the climatic features, plant and animal life of our planet. Let's consider how many oceans there are on Earth, their characteristics and features.
Until recently, it was generally accepted that there were only 4 oceans in the world.
Note! In 2000, representatives of scientific organizations identified a new ocean, which was called the Southern Ocean.
The list looks like this:
- Quiet;
- Atlantic;
- Indian;
- Southern (Antarctic);
- Arctic (Arctic).
Thus, it turns out that there are 5 oceans on Earth. Using modern developments and scientific and technical achievements, scientists can explore the water spaces of our planet in new and unique ways.
This allows not only to study the depths of these reservoirs, but also to prevent possible catastrophic consequences that could occur as a result of climate change in these areas.
New species of living organisms are also regularly discovered, many of which are amazing. But still most of them remain unknown.
World ocean planet
The world ocean is a planetary layer of salty water that includes all known water resources. There is free exchange between parts of a given continuous body of water, which is important for oceanography.
To determine the most important oceanic territories, several criteria are used, for example, archipelagos, continents.
Quiet
The largest (179 million km², it is allocated a third of the surface of the entire planet and half of the World) and ancient among all the others. It is often called the “Great” because it is capable of containing every continent and island of the Earth.
The reservoir received its official name after F. Magellan's trip around the world, during which good, calm weather reigned.
The shape is oval, widened at the equator. It is bounded in the west by the continent of North and South America, in the east by the continent of Australia and Eurasia.
The southern Pacific Ocean is characterized by light, gentle winds and stable weather conditions, but to the west the situation changes: hurricanes are often observed here - southern Australian squalls that gain strength in December.
Tropical waters are transparent, clean, dark blue in color, and their salinity is average. The weather in the equatorial region is favorable: moderate winds, 25 degrees Celsius all year round, calm and clear skies are often observed. The Great Coral Reef stretches along the eastern Australian coast.
The average depth is 3980 meters, the greatest is in the Mariana Trench (11022 m). Volcanic eruptions and tremors are often observed on the coast, both in depth and on the surface of the Earth.
Quiet is home to many species of living creatures - a variety of fish, seals, crabs, octopuses, etc.
The Pacific Ocean plays an important role in the economy of a huge number of states. 50% of the world's catch comes from this body of water. The most important sea routes pass through it. Shipping is active along the coasts of the continents.
Unfortunately, human activity has caused water pollution, and several species of animals have been destroyed. Particularly dangerous for a reservoir is the entry of industrial waste and oil into the water.
Atlantic
This is the second largest ocean on our planet, which is the most developed and explored. The length is 13,000 km, the maximum width is 6,700 km, and the area is 92 km². Its coastline is significantly indented, which forms a huge number of bays and seas, especially in the northern regions.
It is limited to the west by South and North America, and to the east by Africa and Europe.
It was first described in the 5th century BC by Herodotus, a historian of Ancient Greece.
This reservoir cannot boast of a variety of fauna, but only an abundance of biomass. Since ancient times, the Atlantic has been the main hunting ground for mammals and marine fish.
It has a strong influence on the climate of the entire planet. Thanks to the Gulf Stream, European countries are warmed by warm waters.
The intensive economic activity of mankind has greatly deteriorated the environment in the reservoir itself and on the nearby coasts. Today, scientific recommendations are being actively drawn up, and international agreements are being concluded aimed at the reasonable exploitation of ocean resources.
Indian
This reservoir is allocated a fifth of the area of all the world’s waters and a seventh of the entire surface of the Earth. Its area is 76 million km². Its most saline part is the Red Sea (salinity level is 41%). The reservoir is limited by three continents - Australia, Asia and Africa.
Indian has a varied topography: at its bottom there are underwater ridges, basins, and trenches.
The vast majority are located in the Southern Hemisphere.
Indian is the warmest in terms of surface water temperatures. Monsoons are observed in its northern part.
Indian is distinguished by its developed flora and fauna. Natural gas and oil are extracted on the shelf. There are many shipping routes across the surface of the reservoir.
Compared to the other five oceans, the Indian Ocean is the most oil-polluted in the world.
One of the most dangerous natural disasters in human history happened in December 2004 - an earthquake, the epicenter of which was in this ocean, caused an underwater earthquake in this reservoir. Waves 15 meters high reached the shores of many countries - Thailand, Sri Lanka, Indonesia, etc., which caused a huge number of victims (about 300 thousand). Many bodies were washed out to sea, so the exact number of dead could not be determined.
Southern (Antarctic)
It ranks fourth in size. It surrounds Antarctica and covers an area of 86 million km². The greatest depth is about 8428 m, the average is 3500 m.
The southern one has a harsh climate and rich wildlife. Krill are being harvested, but whaling is banned. The total number of whales is 500,000. The following representatives of mammals are found: seals, southern elephant seals, leopard seals. The coast is home to 44 different species of birds, numbering 200 million.
The climatic conditions consist of several distinctive features: a unique geographical location, the influence of the Antarctic continent (ice-covered, high-altitude and cold), and continuous sea ice. Warm currents are not observed. Katabatic winds are formed, the speed of which can sometimes reach 15 m/s.
One of the characteristic features of the Southern water resource is the year-round presence of ice. From September to October, the period of greatest development, ice covers an area of about 18 million km².
Icebergs also form due to the fact that, under the influence of tsunamis and waves, coastal parts of ice and continental glaciers break off. Every year, over 200 thousand icebergs are observed in the waters of this reservoir. They rise 50 m above the sea surface, and their length is approximately 500 m. In 4-5 years, the vast majority of the mass of icebergs thaws.
Northern Arctic (Arctic)
Located between North America and Eurasia.
Note! This is the smallest ocean on our entire planet.
It covers an area of 15 million km², which forms only a few percent of the world's waters as a whole.
The depth of the reservoir is 1225 m (the maximum is 5527 m in the Greenland Sea). As a result, the Arctic Ocean is the shallowest. The Arctic ice is like a great white giant, containing 10 percent of the world's fresh water. It maintains the stability of the Earth's global climate.
The area of the islands is 4 million km². The largest archipelagos and islands are Spitsbergen, Novaya Zemlya, Franz Josef Land, the islands of Vaygach, Kolguev, Wrangel, etc. The island of Greenland is also located within the oceanic waters of the Arctic.
The climate of this reservoir belongs to the Arctic. The overwhelming majority is covered with drifting ice in the winter months of the year. In the summer months, the water temperature rises to +5 degrees.
Polar bears can be found on floating ice. They use the ice as a platform and for hunting. When the ice disappears, these animals will also disappear, as they will begin to starve. However, polar bears live only in the Arctic.
The indigenous population is engaged in fishing for seals and walruses. Fishing is also developed. In the Arctic there are fish that live only in these territories.
When the ice of a reservoir melts, it releases various organisms and nutrients into the water, causing algae to grow. Representatives of the underwater world feed on zooplankton.
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Let's sum it up
How many oceans are there in our world, on the planet at the moment? There are 5 of them on Earth, and the fifth, Southern (Antarctic), officially “appeared” only a few years ago. All the oceans of the world play a vital role in the life of our planet.
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The ocean is the largest of all existing bodies of water on Earth, or the planet's continuous layer of water, and makes up the majority of the Earth's entire hydrosphere. The world's oceans occupy more than 70% of the entire surface of planet Earth. These reservoirs have some features, for example, they are a habitat for many living creatures, and also have a whole system for regulating currents. All planetary shells constantly interact with the largest bodies of water on Earth.
Until recently, the World Ocean had four oceans, but in 2000 a fifth ocean was identified, which geologists called the Southern Ocean. This article is intended to tell about all 5 oceans, their features, animals and plants for which these waters are their habitat.
This ocean is the largest on the planet, with an area of more than 165 million square kilometers. This water area exceeds the area of the entire landmass. It merges with the Southern Ocean in the south and with the Arctic Ocean in the north. Australia, North and South America, as well as Africa are washed by this ocean. In addition, there are also islands of the Pacific archipelago.
The Pacific coast is framed by a whole “ring” of volcanoes. This ring is called “fire”. This is due to the fact that volcanic eruptions most often occur in the fire zone, as well as strong earthquakes.
The floor of the Pacific Ocean is constantly changing as tectonic plates collide with each other, and sometimes “crawl” under each other, thereby creating storms and hurricanes. Therefore, the name “Pacific” is completely unjustified; it is the most restless ocean. Sometimes magma emerges from under the earth's crust, resulting in the formation of underwater volcanoes. This process can lead to the appearance of seamounts and islands.
Covers approximately 360,000,000 km² and is generally divided into several major oceans and smaller seas, with oceans covering approximately 71% of the Earth's surface and 90% of the Earth's biosphere.
They contain 97% of the Earth's water, and oceanographers claim that only 5% of the ocean depths have been explored.
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Because the world's oceans are a major component of Earth's hydrosphere, they are integral to life, form part of the carbon cycle, and influence climate and weather patterns. It is also home to 230,000 known animal species, but since most are unexplored, the number of underwater species is likely much higher, perhaps more than two million.
The origin of the oceans on Earth is still unknown.
How many oceans are there on earth: 5 or 4
How many oceans are there in the world? For many years, only 4 were officially recognized, and then in the spring of 2000, the International Hydrographic Organization established the Southern Ocean and defined its limits.
It’s interesting to know: what continents exist on planet Earth?
Oceans (from the ancient Greek Ὠκεανός, Okeanos) make up most of the planet's hydrosphere. In descending order by area, there are:
- Quiet.
- Atlantic.
- Indian.
- Southern (Antarctic).
- Arctic Oceans (Arctic).
Earth's global ocean
Although several separate oceans are usually described, the global, interconnected body of salt water is sometimes called the World Ocean. TO continuous pond concept with relatively free exchange between its parts is of fundamental importance for oceanography.
The major oceanic spaces, listed below in descending order of area and volume, are defined in part by continents, various archipelagos, and other criteria.
What oceans exist, their location
Quiet, the largest, extends north from the Southern Ocean to the Northern Ocean. It spans the gap between Australia, Asia and the Americas and meets the Atlantic south of South America at Cape Horn.
The Atlantic, the second largest, extends from the Southern Ocean between America, Africa and Europe to the Arctic. It meets the Indian Ocean waters south of Africa at Cape Agulhas.
The Indian, the third largest, extends north from the Southern Ocean to India, between Africa and Australia. It flows into the Pacific expanses in the east, near Australia.
The Arctic Ocean is the smallest of the five. It joins the Atlantic near Greenland and Iceland and the Pacific Ocean in the Bering Strait and spans the North Pole, touching North America in the Western Hemisphere and Scandinavia and Siberia in the Eastern Hemisphere. Almost all of it is covered with sea ice, the extent of which varies depending on the season.
Southern - surrounds Antarctica, where the Antarctic circumpolar current prevails. This sea area has only recently been identified as a separate oceanic unit, which lies south of sixty degrees south latitude and is partially covered by sea ice, the extent of which varies with the seasons.
They are bordered by small adjacent bodies of water such as seas, bays and straits.
Physical properties
The total mass of the hydrosphere is about 1.4 quintillion metric tons, which is about 0.023% of the Earth's total mass. Less than 3% is fresh water; the rest is salt water. The ocean area is about 361.9 million square kilometers and covers about 70.9% of the Earth's surface, and the volume of water is about 1.335 billion cubic kilometers. The average depth is about 3,688 meters and the maximum depth is 10,994 meters in the Mariana Trench. Almost half of the world's sea waters have a depth of more than 3 thousand meters. Vast areas below 200 meters depth cover about 66% of the Earth's surface.
The bluish color of the water is a component of several contributing agents. Among them are dissolved organic matter and chlorophyll. Sailors and other sailors have reported that ocean waters often emit a visible glow that extends for many miles at night.
Oceanic zones
Oceanographers divide the ocean into different vertical zones determined by physical and biological conditions. Pelagic zone includes all zones and can be divided into other areas, divided by depth and illumination.
The photic zone includes surfaces up to a depth of 200 m; it is an area where photosynthesis occurs and therefore has great biological diversity.
Because plants require photosynthesis, life found deeper than the photonic zone must either rely on material falling from above or find another source of energy. Hydrothermal vents are the main source of energy in the so-called aphotic zone (depths greater than 200 m). The pelagic part of the photonic zone is known as epipelagic.
Climate
Cold deep water rises and warms in the equatorial zone, while thermal water sinks and cools near Greenland in the North Atlantic and near Antarctica in the South Atlantic.
Ocean currents greatly influence the Earth's climate by transporting heat from the tropics to the polar regions. By transferring warm or cold air and precipitation to coastal areas, winds can carry them inland.
Conclusion
Many of the world's goods move by ship between the world's seaports. Ocean waters are also the main source of raw materials for the fishing industry. you can find out by following the link.
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According to some sources, there are four oceans in the world: Atlantic, Pacific, Arctic and Indian. According to other sources, there is a fifth ocean - the Southern Ocean.
In the past, for various reasons, some experts distinguished one ocean, two oceans, three oceans. For example, some geographers, oceanologists and other specialists claim that there are three oceans in the world. In their opinion, the Atlantic and Arctic Oceans should be combined into one ocean - the Atlantic. They believe that the Arctic Ocean is a continuation of the Atlantic Ocean. The question arises: are they right in their statement?
Another part of the experts, who say that there are three oceans in the world, propose combining not the Atlantic and Arctic oceans, but the Pacific and Indian oceans into one. Some of them propose to call this association the Great Ocean. I note that the Italian geographer and member of the Vienna Academy of Sciences Adriano Balbi (1782 - 1848) highlighted the Great Ocean in his works.
It should be noted that from 1937 to 1953, five oceans were distinguished. The fifth ocean, which is called the Southern Ocean, also had another name - the Southern Arctic.
Some sources indicate that the International Hydrographic Organization in 2000 made a legally binding decision to divide the World Ocean into five parts. Other sources record that this decision has no legal force. It is necessary to understand whether the decision of the International Hydrographic Organization of 2000 has legal force?
Most sources indicate that the 2000 International Hydrographic Organization decision has not yet been ratified. Let me note that ratification should be understood as the process of giving legal force to a document. From the above it follows that the decision of the International Hydrographic Organization of 2000 does not yet have legal force, that is, the number of oceans is currently four, not five.
I note that in 1953, the International Hydrogeographical Bureau developed a new division of the World Ocean, according to which there are four oceans, not five. The current definition of oceans from 1953 does not include the Southern Ocean. Therefore, there are currently four oceans.
The problem also lies in the fact that some teachers, tutors, teachers, students, schoolchildren and other categories of people cannot clearly determine where the border of the Southern Ocean lies. When I, as a teacher, asked one student to show the boundaries of the Southern Ocean, and then made a similar request to another student, it turned out that each student showed the boundaries of the Southern Ocean in his own way.
I feel sorry for schoolchildren, students and other categories of people, because some teachers, tutors and teachers tell them that there are five oceans in the world, while others tell them that there are four oceans on Earth. The result is confusion in the minds of the students, and this is a mess. I believe that the information in people’s heads in relation to the number of oceans in the world should be the same, that is, it is necessary throughout the world to decide how many oceans there are on Earth - four or five.
From all that has been said, it follows that students, schoolchildren and other categories of people should be told that there are four oceans in the world. We can talk about the fifth ocean, but in this case it must be said that the decision of the International Hydrographic Organization of 2000 has not yet been ratified.
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