Oceans and seas cover 361.26 million km2, or 70.8% of the earth's surface. In the northern hemisphere, land occupies 39.4% of the surface of our planet, oceans - 60.6%, in the southern hemisphere, land accounts for only 19%, while the ocean - 81%.
More than one third of the earth's surface is occupied by the Pacific Ocean. It is the deepest, coldest and least saline ocean, although it receives a relatively small portion of river flow. Near the equator, the width of the Pacific Ocean reaches 17 thousand km.
The second largest ocean, the Atlantic, is relatively narrow. Its width is approximately 5000 km. It stretches like a winding ribbon between the poles. If the area occupied by the Pacific Ocean reaches 178.7 million km2, then the area of the Atlantic Ocean is 91.6 million km2. It is shallower than the Pacific Ocean. Its average depth is 3597 m (Tikhogo - 3940 m). In this respect, it is inferior to the Indian Ocean, whose average depth is 3711 m with an area of 76.17 million km2. Many large rivers discharge water into the Atlantic Ocean. The volume of water carried by the Amazon and Congo alone accounts for about 25% of the total flow of rivers flowing into the ocean. Despite this, Atlantic waters are the most saline - 34-37.3% (the average salinity of ocean waters is 34.71%). These are also the warmest waters, their average temperature reaches 3.99 ° C (the World Ocean - 3.51 ° C). This paradoxical situation is due to the high level of exchange between the Atlantic Ocean and the marginal seas, the Mediterranean Sea and the Gulf of Mexico, whose waters are characterized by high temperatures and high salinity.
The third largest ocean, the Indian Ocean, is mostly located in the southern hemisphere. It reaches its maximum width in the very south, between South Africa and New Zealand, 15 thousand km. Three major rivers flow into the Indian Ocean basin - the Ganges, Indus and Brahmaputra. The average water temperature in the Indian Ocean is 3.88 ° C, the average salinity is 34.78%, i.e., close to the average for the World Ocean.
The smallest and shallowest is the Arctic Ocean. Its salinity is low, since it is surrounded on all sides by land, from which many small and large rivers flow. A significant part of the ocean surface is covered with ice.
Although modern oceans have different sizes, their structure is approximately the same. In any ocean, approximately three equivalent zones can be distinguished: continental margins, abyssal basins and mid-ocean ridges. Continental margins, including the shelf, slope and its foot, occupy approximately 20.5% of the surface of the ocean floor, abyssal basins account for 41.8% of their area, and mid-ocean ridges and rises of the central ocean type account for 32.7%. The last value is typical for all oceans. The relationship between the continental margins and abyssal basins varies within quite significant limits. Thus, in the Atlantic Ocean, where the width of the shelves is greatest, the continental margins occupy approximately 28% of the bottom area, and abyssal basins - 38%. In the Pacific Ocean the situation is reversed: 15.7% are underwater continental margins, 43% are abyssal basins. True, there are many deep-sea trenches, but their area is only 2.9% of the total ocean area. Free-standing submarine volcanoes and volcanic ridges are most numerous in the Pacific Ocean, but they occupy a smaller area there than in the Indian Ocean (2.5% compared to 5.4%). However, many of these figures still need clarification.
Stable systems of surface and bottom currents have developed in the oceans. The pattern of distribution of warm and cold surface currents in the largest ocean basins is approximately the same. In equatorial regions, wind transport from east to west dominates, which gives rise to the northern and southern equatorial currents. The first operates in the northern hemisphere, the second in the southern hemisphere. They are separated by a rather narrow zone, within which water transfer occurs in the opposite, eastern direction. This is the so-called Equatorial Countercurrent.
Each of the equatorial currents is associated with a relatively closed system of other currents that form a macrocirculation cell. Thus, the North Equatorial Current in the Atlantic Ocean, deviating to the north near the ridge of the Lesser Antilles, generates the warm Gulf Stream. The latter moves first along the continental margin of North America and then crosses the North Atlantic. From here, cooled waters begin to move south toward the equator, forming the cold Canary Current. In the northern part of the Pacific Ocean, the role of the Gulf Stream is played by another warm current, the Kuroshio, which rises to moderate and high latitudes along the coast of Japan. Cooling, the waters brought by Kuroshio rush south, moving near the Pacific coast of North America. This cold boundary current is called the California Current. Large macrocirculation cells also emerged in the southern half of the Atlantic, Pacific and Indian oceans. Here, in high latitudes, under the influence of the prevailing westerly winds around Antarctica, a powerful current of the Western Winds operates. Some of its branches, deviating to the north, in the form of cold boundary currents rush to the equator along the western coasts of Africa, Australia and South America. Deflected by trade winds, the main branches of these currents follow further through the tropics to the western continental margins, from where they move south in the form of warm waste currents. These subtropical macrocirculation cells, as in the northern hemisphere, are anticyclonic in nature. Other branches of cold compensation currents, deviating to the east, form small circulation cells of the cyclonic type in the eastern periphery of the tropical zone of the oceans. In the subpolar and polar regions of the northern hemisphere, in the areas of the Icelandic and Aleutian lows, there are cyclonic gyres, well expressed in the autumn-winter seasons.
Differences in the density and temperature of surface and bottom waters give rise to vertical water exchange. The consequence of this is the emergence of bottom geostrophic currents directed from high latitudes to the equator. Since these underwater rivers flow along the continental slopes and over their feet, that is, along the contours of the continents in the western regions of the oceans, they are called contour currents. The most powerful of them cross the equator, penetrating into the other hemisphere.
These are, in the most general terms, the features of modern oceanic circulation. All of the above indicates that ocean basins are separate cells of a single integral system, constructed in a structural, morphological and oceanological sense quite uniformly. Next, we will show that the evolution of the oceans and the geological processes occurring in them obey the same laws.
Differences and common features of the oceans.
At the moment, the differences between the Pacific, Atlantic, Arctic and Indian oceans are quite conditional. They all represent one huge ocean. It all depends on which continents and continents are washed by these waters and in what latitudes they are located.
How does the Pacific Ocean differ from the Atlantic: comparison, similarities, differences
The largest in area and deepest are the Pacific waters. They are the warmest. We can say that the name Quiet arose from the time of Magellan’s voyage. He found that for several months, while they were sailing, the water was not stormy. And in general, they successfully conducted their expedition.
Features and differences:
- The Mariana Trench is located in the Pacific Ocean. It is thanks to her that the ocean is the deepest. There are many similarities between the Atlantic and Pacific. These oceans are predominantly found in warm tropical latitudes. That is why the water in them is quite warm.
- Regarding the differences, the Pacific and Atlantic Oceans differ in water salinity. The Atlantic is saltier. This is due to the fact that its size and depth are much smaller than that of the Quiet.
- The high salinity and temperature in the Atlantic waters is explained by the fact that they are fed by many coastal rivers and seas that depart from warm continents with high air temperatures. Therefore, the water flowing into the Atlantic Ocean is much warmer.
- The most interesting thing is that lovers of resort holidays recommend spending their holidays in Pacific waters. There are rarely storms here. The islands rarely experience heavy rainfall or hurricanes.
How does the Pacific Ocean differ from the Indian Ocean: comparison, similarities, differences
These oceans have quite a lot in common. The common continents that wash these oceans are Asia, Antarctica and Australia. Pacific and Indian waters merge into one. The conditional border is located along the Malay Archipelago, the southern coast of New Guinea. This border also runs through Bass Strait and from Tasmania, along the meridian to Cape Williams.
How does the Atlantic Ocean differ from the Indian Ocean: comparison, similarities, differences
- Atlantic and Indian waters differ in area, depth and salinity.
- It is worth noting that there are also common continents that share oceans. This is Africa and Antarctica.
- Regarding the relief, it is significantly different. The bottom of the Atlantic Ocean is quite relief, and almost along its entire length it consists of long Ridges. The bottom of the Indian Ocean is smoother and shallower.
How is the Arctic Ocean different from other oceans?
The main difference between the Arctic Ocean and the rest is that it is located in polar latitudes.
Differences:
- This ocean is the coldest and smallest. In addition, the salinity of this ocean is the lowest in comparison with the others. This is due to the fact that glaciers absorb salt. And most freshwater rivers flow into this ocean.
- The ocean is located in the center of the Arctic. It washes continents such as Eurasia and North America. The biggest difference from other oceans is that there is almost always ice on the surface of the ocean.
- Another feature of this ocean is that its bottom is very complex. A third of the entire bottom area is occupied by the shelf. There are also underwater ridges, such as the Lomonosov and Mendeleev ridges. In addition, the bottom is covered with faults.
Arctic Ocean How the oceans differ from each other: comparison, similarities, differences, conclusion
The difference between all oceans is quite arbitrary. It is determined by the temperature of the waters and the continents washed by it. Indian waters differ from all others in that they have no connection with the Arctic Ocean. The warmest and deepest is the Pacific Ocean. It is distinguished by a large number of islands, as well as a calm bottom topography.
Atlantic waters stretch from north to south. We can say that they are located in a long strip along the continents. It is worth noting that at certain points many of the oceans mix. At the same time, the division of waters is quite conditional.
As you can see, all oceans are part of the World Ocean. The largest and deepest is the Pacific Ocean. It makes up 53% of the total area of the World Ocean.
VIDEO: Differences between oceans
Oceans are reservoirs of salt water that cover 70% of the Earth's surface. Life on Earth is believed to have originated in the ocean, and it continues to be home to various types of life. Oceans influence weather and temperature by absorbing solar radiation. Oceans make a huge contribution to the water cycle and are the main sources of precipitation. Although the single ocean is usually divided into several "individual" oceans, it is actually one global ocean, sometimes called the World Ocean. The area of the World Ocean is 361 million square kilometers.
The Earth's oceans are all connected to each other. Let's compare the oceans and find out which ocean is the largest:
Pacific Ocean:
It is the largest of all oceans and separates Asia and Oceania from South America. It has an area of 165,250,000 square kilometers and is bordered by Asia and Australia to the west and North and South America to the east. It extends from the Arctic in the north to the Antarctic Ocean in the south. Its average depth is 4,028 m, it is also the deepest ocean - the depth of the Mariana Trench is 11,033 m
Atlantic Ocean:
It is the second largest ocean with an area of 106,400,000 square kilometers. The Atlantic Ocean occupies an elongated, S-shaped basin between Europe and Africa in the east, North and South America in the west, it is bounded in the north by the Arctic Ocean, in the southwest by the Pacific Ocean, in the southeast by the Indian Ocean, and in the south by the Antarctic Ocean. Its average depth is 3,926 m, the maximum depth is the Puerto Rico Trench 8,605 meters
Indian Ocean:
The Indian Ocean is the third largest of all oceans covering an area of 73,560,000 square kilometers. It is bordered to the north by the Indian and Arabian Peninsulas, to the west by East Africa, to the east by Indochina, the Sunda Islands and Australia, and to the south by the Antarctic Ocean. The ocean is named after the geographical location of India. Its average depth is 3,963 m, the maximum depth is the Java Trench 7,724 meters
Antarctic Ocean:
The Antarctic Ocean includes the southern waters of the World Ocean. It is considered the fourth largest ocean in the world, covering an area of over 20,330,000 square kilometers. Its average depth is from 4,000 to 5,000 m, the maximum depth is in the southern part of the South Sandwich Trench 7,236 meters
Arctic Ocean:
The Arctic Ocean is the smallest and shallowest of the world's five largest oceans; its area is 8,207,654 square kilometers. It is surrounded by Eurasia and North America and is partially covered by ice throughout the year. The Arctic Ocean's temperature and salinity vary seasonally with the melting and freezing of ice sheets, and it has the lowest salinity of the five major oceans, due to low evaporation, freshwater inflows from rivers and streams, and limited oceanic inflow and outflow.
These are the main differences between Earth's oceans. We hope you found this information useful!
This I know
2. In what climatic zones is the Atlantic Ocean located?
The Atlantic Ocean is located in all climate zones except the Arctic.
3. What are the main features of atmospheric circulation in the Northern Indian Ocean?
In the northern part, the ocean is exposed to tropical monsoons.
4. How do human activities affect the nature of the oceans?
Economic activities have a negative impact on the nature of the oceans. Its influence is especially strong in the Atlantic Ocean. This ocean has long been a place of active fishing and fishing, transport links, and oil and gas production. The main problem of the ecology of the Atlantic (and, first of all, its northern waters) is the increasing anthropogenic impact, which can have irreversible negative consequences. In general, anthropogenic impact can be reduced to the following: 1) overfishing (especially in recent decades); 2) noise pollution (geophysical exploration, drilling operations, ship propeller noise); 3) oil pollution; 4) contamination with pesticides; 5) household pollution (garbage, sewage); 6) radioactive background of ships; 7) acid rain.
Water pollution with oil and petroleum products has become a major problem in the Indian Ocean. Its waters, flora and fauna. Accidents and spills of oil during production, pumping and transportation can and do lead to the death of marine animals, birds, fish, shellfish and other aquatic life.
I can do this
7. Using the maps in Figures 18 and 23, determine how the boundaries of lithospheric plates lie in the Atlantic and Pacific oceans.
The boundaries of lithospheric plates in the Atlantic Ocean run from north to south along the mid-ocean ridges and divide the ocean almost in half. The Indian Ocean was formed at the boundary of three lithospheric plates - the Indo-Australian, African and Antarctic. The mid-ocean ridges of the Arabian-Indian, West Indian and Australian-Antarctic divide the ocean floor into separate basins.
8. Using Internet search engines and your biological knowledge, find information about such inhabitants of the Indian and Atlantic Oceans as the manatee and dugong.
Like whales, sirens descended from land mammals that mastered the water element. However, despite their external similarities, whales and sirens have different ancestors. Apparently, the closest relatives of sirens in the animal world are elephants. A complex evolutionary path led to the emergence of these two outwardly completely different groups of animals. It has been proven that fossil sirens had many common characteristics with elephants: a similar structure of the skull and teeth. In addition, modern manatees have small clawed hooves on their flippers; Elephants also have similar hooves.
DUGONGS AND MANATEES
It is easy to distinguish a dugong from a manatee by the shape of its tail - manatees have a rounded tail, without a notch, while dugongs have a triangular tail with a deep notch in the middle. Dugongs are somewhat larger than manatees (the body length of a dugong is 3-5 m, and a manatee is 2-4 m), and they live only in the salty waters of oceans and seas, while manatees have adapted to live not only in the seas, but also in fresh waters. The Brazilian manatee, for example, lives exclusively in the Orinoco and Amazon river basins. Dugongs and manatees are exemplary parents. Newborns are born fully formed and quite large - their body length is about 1/3 of the mother's body length. A mother feeds her only child with milk for 18 months.
Dugongs You can often see how a baby, tired of swimming on its own, rides on its mother’s carefully supported back. The father also takes part in raising the baby, bravely protecting his child from any danger, be it a shark or a person.
Manatees are very trusting and sociable, quickly tamed and easily tolerate captivity. Dugongs, on the contrary, feel good only in natural conditions, and it is extremely difficult to breed them in special nurseries.
As you know, the territory of our planet is washed by four oceans. The Atlantic and Indian oceans rank second and third in terms of volume of water, respectively.
The waters of these oceans are home to unique species of aquatic animals and vegetation.
History of the discovery of the Atlantic Ocean
The development of the Atlantic Ocean began in early Antiquity. It was then that the ancient Phoenician sailors began to make their first voyages along the Mediterranean Sea and the eastern coast of the Atlantic Ocean.
However, only the European northern peoples managed to cross the Atlantic Ocean in the 9th century. The famous navigator started the “golden era” of Atlantic exploration Christopher Columbus.
During his expeditions, many seas and bays of the Atlantic Ocean were discovered. Modern oceanographers continue to study the Atlantic Ocean, in particular the relief structures of its bottom.
History of the discovery of the Indian Ocean
The history of the discovery of the Indian Ocean goes back to the times of ancient civilizations. The ocean served as the main trade route for the Persians, Indians, Egyptians and Phoenicians.
The Chinese were the first to explore the Indian Ocean. It was to the Chinese navigator Ho's wife managed for the first time during his expedition to explore the shores of Sri Lanka, the Arabian Peninsula, Persia and Africa.
Large-scale exploration of the Indian Ocean began with the first Portuguese expeditions Vasco de Gama, who managed not only to reach the shores of India, completely circumnavigating the African coast, but also to discover many islands in the Indian Ocean.
Atlantic Ocean: general information
The Atlantic Ocean ranks second among the world's oceans in size. Its waters cover an area of 80 million square meters. km.
The formation of the Atlantic Ocean began more than 150 million years ago, at a time when the modern American continent began to separate from Eurasia. The Atlantic Ocean is considered the youngest among all existing oceans.
The maximum depth reaches 9 km(a trench located off the coast of Puerto Rico). The Atlantic Ocean washes the shores of the following continents: Eurasia, Africa, South and North America, as well as Antarctica.
Indian Ocean: general information
Indian Ocean, with an area of about 70 million km. sq., ranks third in size among other oceans. The deepest place in the Indian Ocean is a depression near java islands(Indonesia), the depth of which reaches 7 km.
The waters of the Indian Ocean are characterized by frequent changes in current direction. The Indian Ocean washes Eurasia, Africa, Australia, and Antarctica.
