The hydrosphere is the shell of the Earth, which is formed by oceans, seas, surface reservoirs, snow, ice, rivers, temporary flows of water, water vapor, clouds. The shell is made up of reservoirs and rivers, and the oceans are intermittent. The underground hydrosphere is formed by underground currents, groundwater, and artesian basins.
The hydrosphere has a volume equal to 1,533,000,000 cubic kilometers. Water covers three-quarters of the Earth's surface. Seventy-one percent of the Earth's surface is covered by seas and oceans.
The huge water area largely determines the water and thermal regimes on the planet, since water has a high heat capacity and contains great energy potential. Water plays a large role in the formation of soil and the appearance of the landscape. The waters of the world's oceans differ in their chemical composition; water is practically never found in distilled form.
Oceans and seas
The world ocean is a body of water that washes the continents; it makes up more than 96 percent of the total volume of the earth's hydrosphere. The two layers of the water mass of the world's oceans have different temperatures, which ultimately determines the temperature regime of the Earth. The world's oceans accumulate energy from the sun and, when cooled, transfer some of the heat to the atmosphere. That is, the thermoregulation of the Earth is largely determined by the nature of the hydrosphere. The world ocean includes four oceans: Indian, Pacific, Arctic, Atlantic. Some scientists highlight the Southern Ocean, which surrounds Antarctica.
The world's oceans are distinguished by the heterogeneity of water masses, which, located in a certain place, acquire distinctive characteristics. Vertically, the ocean is divided into bottom, intermediate, surface and subsurface layers. The bottom mass has the largest volume and is also the coldest.
The sea is the part of the ocean that juts out into the mainland or is adjacent to it. The sea differs in its characteristics from the rest of the ocean. Sea basins develop their own hydrological regime.
The seas are divided into internal (for example, the Black, Baltic), inter-island (in the Indo-Malayan archipelago) and marginal (Arctic seas). Among the seas there are inland (White Sea) and intercontinental (Mediterranean).
Rivers, lakes and swamps
An important component of the Earth's hydrosphere are rivers; they contain 0.0002 percent of all water reserves and 0.005 percent of fresh water. Rivers are an important natural reservoir of water, which is used for drinking, industrial and agricultural needs. Rivers are a source of irrigation, water supply, and water supply. Rivers are fed by snow cover, groundwater and rainwater.
Lakes appear when there is excess moisture and in the presence of depressions. Basins can be of tectonic, glacial-tectonic, volcanic, or cirque origin. Thermokarst lakes are common in permafrost areas, and floodplain lakes are often found in river floodplains. The regime of lakes is determined by whether the river carries water out of the lake or not. Lakes can be drainless, flowing, or represent a common lake-river system with a river.
On the plains, in waterlogged conditions, swamps are common. Lowland ones are fed by soils, highland ones by sediments, transitional ones by soils and sediments.
The groundwater
Groundwater is located at different depths in the form of aquifers in the rocks of the earth's crust. Groundwater lies closer to the surface of the earth, groundwater is located in deeper layers. Mineral and thermal waters are of greatest interest.
Clouds and water vapor
Condensation of water vapor forms clouds. If the cloud has a mixed composition, that is, it includes ice and water crystals, then they become a source of precipitation.
Glaciers
All components of the hydrosphere have their own special role in global processes of energy exchange, global moisture circulation, and influence many life-forming processes on Earth.
1. What is the hydrosphere? What parts of it can be seen on a physical map? What symbols are they indicated by? What parts of the hydrosphere are not shown on the map?
Hydrosphere is the watery shell of the Earth. On the physical map you can see seas and oceans, rivers and lakes, swamps, glaciers. Elements of the hydrosphere on a physical map are reflected in different shades of blue and cyan. Seas and oceans are shown in blue and cyan colors, depth is determined by the depth scale. Lakes are also indicated in blue. Salt lakes - purple, lilac. Rivers are shown with sinuous lines that follow the shape of the river bed. Swamps are marked by horizontal shading over the topography. Glaciers are shown on maps in white with small dark dots. The physical map does not show groundwater.
2. What is the special role of the water cycle for nature?
The water cycle ensures the connection of all parts of the hydrosphere into a single whole. This makes it possible for different areas to form precipitation and receive water.
3. What phenomena do you observe in nature that confirm the water cycle?
Evaporation of water, condensation of water vapor, precipitation, seepage of water into the soil, currents.
4. What is the importance of the hydrosphere for humans and the Earth as a whole?
The hydrosphere is a prerequisite for life on Earth. Water is vital for all living organisms. The hydrosphere influences the relief and climate.
5. How does the marginal sea differ from the internal one? Using a map, give examples of marginal and inland seas.
The marginal seas protrude slightly into the continents and are limited on the ocean side by islands and rises of underwater relief. Inland seas cut far into the land. The marginal seas are the Okhotsk Sea, the Laptev Sea, and the Northern Sea. Inland seas – Black Sea, Mediterranean Sea.
6. Name the seas that wash our country. What oceans do they belong to?
The Arctic Ocean basin includes six seas: Barents, White, Kara, Laptev, East Siberian and Chukchi. The Pacific Ocean basin includes three seas: Bering, Okhotsk and Japan, washing the eastern coast of the country. Three seas belong to the Atlantic Ocean basin: the Baltic, Black and Azov. The Caspian Sea belongs to the internal drainage basin.
7. Why do people study the ocean?
8. Using a world map, describe the geographical location of the Mediterranean Sea by filling in the blanks in the sentences:
Refers to the Atlantic Ocean. Located in the North Atlantic Ocean. Connects to the Atlantic Ocean through the Strait of Gibraltar. It has an approximate length of 3800 km and a width of 130 km (determine using scale). The northern, western and eastern parts are washed by the continent of Eurasia, and the southern part by the continent of Africa. It has large islands: Sicily, Sardinia, Crete.
9. List the properties of ocean waters. Are they the same everywhere in the ocean?
Properties of ocean waters - color, transparency, temperature, salinity. These properties are different in different territories.
10. What causes the differences in the properties of waters in different regions of the World Ocean?
Differences in the properties of water in most cases depend on the amount of incoming solar energy.
Using Figures 146 and 147, observe how the temperature and salinity of surface ocean waters change along the 180° meridian. Present the results in a notebook in the form of a table.
TEMPERATURE AND SALINITY OF OCEAN WATER ALONG THE 180° MERIDIAN
Observe how the temperature and salinity of surface waters change depending on latitude. Draw conclusions from the established facts.
The temperature of surface waters decreases from the equator to the poles, which is associated with a decrease in solar heat that the surface receives. The salinity of surface waters depends on temperature and evaporation. The warmer the water, the higher its salinity. Therefore, the salinity of waters also decreases from the equator to the poles. However, water reaches its maximum salinity in the tropics, and not at the equator. This is due to the fact that large amounts of precipitation fall at the equator, which desalinizes the water.
11. What are the main types of water movements in the oceans? What is the main reason for these movements in the surface layers of water?
The main types of water movement in the ocean are waves and currents. The main reason for these movements is the wind.
12. Name the main river in your area and find it on the map. Describe this river.
CHARACTERISTICS OF THE VOLGA RIVER
a. Where does it begin?
The Volga originates in the Valdai Hills
b. Where does it flow?
Flows into the Caspian Sea
c. Which river (lake, sea) does it belong to?
Belongs to the Caspian Sea basin
d. What kind of terrain does it flow through (plains, mountains).
Flows across the East European Plain
e. What tributaries does it have?
It has many tributaries. The largest tributaries are the Oka, Kama, Vetluga, Kostroma, Unzha, and Sura.
f. What power sources and mode features does it have?
The Volga is mainly fed by snow (60% of the annual runoff), groundwater (30%) and rainwater (10%). The natural regime is characterized by spring floods (April - June), low water availability during the summer and winter low water periods and autumn rain floods (October).
g. How it is used on the farm.
The Volga is used as a shipping artery. Hydroelectric power stations were built on the river. Water is withdrawn for the needs of industry and agriculture.
h. What dangerous phenomena are observed.
Before the river flow was regulated, there were frequent floods.
i. How can you protect a river from pollution?
To protect the river waters, it is advisable to install treatment facilities at adjacent enterprises and control wastewater discharges. It is also necessary to properly use chemicals and fertilizers on agricultural lands in the river basin.
13. Classify lakes according to the origin of the basin, the presence of runoff, and salinity. Present the results in table form.
CLASSIFICATION OF LAKES ACCORDING TO DIFFERENT PRINCIPLES
14. Using a physical map, identify the record-breaking lakes. Fill out the table in your notebook.
15. What is groundwater? What significance do they have in people's lives?
Groundwater is water found in the rocks of the earth's crust. Groundwater is used for water supply. Mineral waters are used for medicinal purposes.
16. Can human economic activity contribute to the melting of glaciers and permafrost? Give examples of such types of economic activities.
Human economic activity can contribute to the melting of glaciers and permafrost. As a result of the work of industrial enterprises and transport, large amounts of carbon dioxide are released into the atmosphere. Carbon dioxide traps heat in the atmosphere, causing global warming and melting glaciers. The melting of permafrost may also be associated with the operation of enterprises and power plants. Thermal power plants use water from lakes and reservoirs for cooling. This leads to an increase in temperature in the reservoir and can cause permafrost to melt.
17. What measures can you propose to reduce human consumption of water resources?
To reduce the consumption of water resources, it is necessary to introduce new technologies that allow water to be reused in enterprises.
Any significant reduction in water loss, use or pollution, as well as the preservation of water quality. Implementation of water management systems that reduce or facilitate the reduction of excess water consumption. This can take the form of installing water meters, reusing wastewater, using seawater and rainwater for drainage, etc.
Questions to the paragraph “Waters of the World Ocean”,
“Scheme of surface currents” – grade 7
I group of questions:
1. What is the role of the ocean in the life of the Earth?
2. Which ocean is the warmest?
3. How does temperature change with depth?
4. What reasons influence the value of salinity?
5. Which ocean is the saltiest and why?
6. Which ocean is the least salty and why?
7. At what temperature does sea water freeze? Why?
8. At what latitudes does ice form?
9. What is water mass?
10. What properties are water masses characterized by?
11. What are currents?
12. What are their temperature and origin?
13. How are currents shown on the map?
14. What current influences the climate of the eastern coasts of North America?
15. The shores of which sea are currents?
Group II questions:
1. Where did such a huge mass of water on Earth come from?
2. What determines the salinity and temperature of water?
3. What is the role of the ocean in retaining solar heat on Earth?
4. Where did the salts in ocean water come from? Why isn't the ocean getting saltier?
5. Is it possible to identify the general direction of change in salinity?
6. What kind of glacier is it in terms of duration of existence and dynamism?
7. How are wind directions and currents related?
8. What happens to the flow of water (current) when it meets the mainland?
9. Famous climatologist A.I. Voeikov called the currents of the World Ocean “the heating system of the planet.” Explain how you understand this fact.
10. Why does the West Winds flow around Antarctica from west to east?
III group of questions:
1. Why is the average annual water temperature higher than air?
2. Why are surface waters warmer in the northern hemisphere than in the southern hemisphere?
3. Why does the Atlantic Ocean have the highest salinity in tropical latitudes?
4. What reasons does the value of salinity in different parts of the World Ocean depend on?
(Mediterranean – 39, Black -18, Kara – 10, Barentsevo – 35, Krasnoe – 42,
Caribbean - 35 ppm).
5. What is the connection between the transparency of the sea and its geographical location?
(White – 8 m, Barentsev – 11-13 m, Mediterranean – 60 m).
Show on the current map:
Warm currents: Gulf Stream, North Atlantic, Brazilian, South Passat, North Passat, Kuroshio, North Pacific;
Cold currents: Californian, Peruvian, Canary, Benguela, Western Winds.
Questions for the paragraphs “Life in the ocean”, “Interaction of the ocean with the atmosphere and land” – grade 7
I group of questions:
1. What three groups are marine animals divided into based on their lifestyle?
2. What are the two areas of life in the ocean?
3. What factors influence the distribution of organisms in the ocean?
4. Name the depth below which there are no green algae and the ocean is inhabited only by animal organisms and bacteria.
5. Which latitudes have the greatest concentrations of organisms?
6. What biological resources is the ocean rich in?
7. In what sectors of the economy are marine animals used?
8. How is the World Water Cycle carried out?
9. What role does the World Water Cycle play in nature?
10. What is breeze and monsoon?
11. Name and show warm and cold currents.
Group II questions:
Why is the top 50 meters of water in the ocean most populated?
How did animals adapt to live on the ocean floor?
Why is the ocean called a heat sink on the planet?
What is the difference between maritime and continental air masses?
Explain the origin of monsoons and their influence on land climate in different seasons of the year.
Explain what effect warm and cold currents have on the climate of coastal areas?
III group of questions:
Why are there more marine organisms closer to shore than in the open ocean?
How do living conditions for organisms in the ocean differ from living conditions on land?
How can we explain that the living conditions in the ocean from the poles to the equator, from the surface to the maximum depths are very different?
How is heat and moisture exchanged between the ocean and land?
Show on the map:
Heavily polluted seas: Mediterranean, Northern, Baltic, Black, Azov, Japanese, Javanese, Yellow, Caribbean;
Heavily polluted bays: Biscay, Persian, Mexican, Guinean.
Answers can be completed 1) in Word and sent to an email address xlesi@ rambler. ru indicating the child’s last name, first name, class, topic of assignment; no later than 3 days after the missed lesson; 2) in writing in workbooks and hand in to the teacher at school, no later than 3 days after the missed lesson
Area: 361.3 million km² (71% of the earth's surface) Volume: 1340.7 million km³ (1/800 of the earth's volume and 96.5% of the total amount of water on the planet) Average depth: 3711 m Maximum depth: m (Mariana Trench ) Average temperature: 3.73° C Average salinity: 34.72 Water balance: precipitation – 458 thousand km³/year, evaporation – 505 thousand km³/year, river flow – 47 thousand km³/year Brief information
Land areas The world's oceans are divided by land areas, these are: continents - large areas of land surrounded by water; islands - areas of land (usually of natural origin), surrounded on all sides by water and constantly rising above the water even at the highest tide; peninsulas - parts of land, one side adjacent to the mainland or island, and surrounded by water on all other sides; archipelagos - a group of islands located close to each other and usually having the same origin (continental, volcanic, coral) and similar geological structure.
Answer questions 1. What continents do you know? Show them on the map. 2. Name the largest continent. 3. Name the smallest continent. 4. Name the coldest continent. 5. Name the hottest continent. 6. What islands do you know? Show them on the map. 7. What peninsulas do you know? Show them on the map. 8. Find the archipelagos on the map: Novaya Zemlya, the Japanese Islands, the British Isles, New Zealand.
The Pacific Ocean occupies half of the Earth's total water surface, and more than thirty percent of the planet's surface area. 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. Pacific Ocean The Pacific Ocean is the largest ocean on Earth. The area of the Pacific Ocean is 179.7 million sq. km, its average depth is 3984 m, its maximum depth is m (Mariana Trench), the volume of water is 723.7 million cubic km.
Atlantic Ocean The Atlantic Ocean is the second largest ocean on Earth after the Pacific. The area of the Atlantic Ocean is 91.6 million sq. km. The volume of water contained by the Atlantic Ocean is equal to a quarter of the total volume of the World Ocean and amounts to 329.7 million cubic km. Average depth km, maximum (Puerto Rico depression). The name of the ocean comes from the name of the Titan Atlas (Atlas) in Greek mythology.
Arctic Ocean The Arctic Ocean is the smallest ocean on Earth by area, located entirely in the northern hemisphere, between Eurasia and North America. The ocean area is 14.75 million km², the volume of water is 18.07 million km³. The average depth is 1225 m, the greatest depth is 5527 m in the Greenland Sea. Most of the bottom relief of the Arctic Ocean is occupied by the shelf (more than 45% of the ocean floor) and the underwater margins of continents (up to 70% of the bottom area).
Indian Ocean The Indian Ocean is the third largest ocean on Earth, covering about 20% of its water surface. Its area is 76.17 million km², volume 282.65 million km³. The deepest point of the ocean is located in the Sunda Trench (7729 m). The Indian Ocean is the youngest and warmest among the world's oceans. Most of it is located in the southern hemisphere, and in the north it extends far into the mainland, which is why ancient people considered it just a big sea.
Southern Ocean The Southern Ocean is the conventional name for the waters of the three oceans (Pacific, Atlantic and Indian) surrounding Antarctica and sometimes unofficially identified as the “fifth ocean”, which, however, does not have a clearly delineated northern border by islands and continents. The conventional area is 20.327 million km² (if we take the northern boundary of the ocean to be 60 degrees south latitude). The greatest depth (South Sandwich Trench) is 8428 m. As of 1978, the concept of “Southern Ocean” is absent in all Russian-language practical marine manuals, and the term is not used among seafarers. In 2000, the International Hydrological Organization adopted a division into five oceans, but this decision was never ratified. The current definition of oceans from 1953 does not include the Southern Ocean.
The sea is part of the ocean; it differs from it in the properties of water (temperature, salinity), currents, and organisms living in it. It is separated from the ocean by islands, peninsulas or seabed rises. Depending on their isolation from the ocean, seas can be internal or marginal. Seas Inland seas extend far into the land and are connected to the ocean by straits. Marginal seas are located on the outskirts of continents. They practically do not resort to land and are poorly separated from the ocean.
Seas of the Pacific Ocean Bering Okhotsk Japanese Yellow Bellingshausen Sea South China Sea Java Sea Tasman Sea Mindanao Flores Moluccan Ross Sea Seram Solomono Sulawesi Sulu Coral Fiji East China Philippine New Guinea Amundsen Sea Banda Inland Japanese Fig. Japanese Sea
Marginal seas (from west to east): Barents Sea, Kara Sea, Laptev Sea, East Siberian Sea, Chukchi Sea, Bafort Sea, Lincoln Sea, Greenland Sea, Norwegian Sea Inland seas: White Sea, Baffin Sea Arctic Ocean seas Fig . East-Siberian Sea
Determine the geographical location of the sea Option 1 – Bering Sea Option 2 – Black Sea Action plan according to plan points 1. Name1. Name and show the sea 2. Geographical position: a) in the World Ocean b) relative to other geographical objects 2. Determine: a) in which part of the ocean, between which meridians and parallels it is located, what is the approximate extent; b) which part of the coast of which continents and islands washes it; what straits are connected to the oceans and seas
Bays A bay is a part of an ocean, sea or lake that extends deep into the land, but has free water exchange with the main part of the reservoir. The largest bays of the World Ocean include the bays of Alaska, Bengal, Biscay, Great Australia, and Guinea. Show the named bays on the map.
Straits A strait is a body of water located between two land areas and connecting adjacent water basins or parts thereof. EXERCISE. Using the atlas maps, determine which oceans connect: a) the Bering Strait; b) Strait of Magellan. What continents or islands separate these straits?
Physical education lesson 1. Starting position - sitting on a chair, smoothly tilt your head back, tilt your head forward, do not raise your shoulders. Repeat 4-6 times. The pace is slow. 2. Starting position - sitting, hands on the belt. 1 - turn the head to the right, 2 - i.p., 3 - turn the head to the left, 4 - i.p. Repeat 6-8 times. The pace is slow. 3. Starting position - standing or sitting, hands on your belt. 1 - swing your left hand over your right shoulder, turn your head to the left, 2 - i.p., the same with your right hand. Repeat 4-6 times. The pace is slow. 1. Exercises to improve cerebral circulation: 2. Exercises to relieve fatigue from the small muscles of the hand Starting position - sitting, arms raised up. 1 - clench your hands into fists, 2 - unclench your hands. Repeat 6-8 times, then relax your arms down and shake your hands. The pace is average.
Physical education for the eyes 1. Blink quickly, close your eyes and sit quietly, slowly reading up to 5. Repeat 4-5 times. 2. Close your eyes tightly (count to 3), open them, look into the distance (count to 5). Repeat 4-5 times. 3. Extend your right arm forward. Follow with your eyes, without turning your head, the slow movements of the index finger of your outstretched hand to the left and right, up and down. Repeat 4-5 times. 4. Look at the outstretched index finger for the count of 1-4, then move your gaze into the distance for the count of 1-6. Repeat 4-5 times. 5. At an average pace, make 3-4 circular movements with your eyes to the right side, and the same amount to the left side. Having relaxed the eye muscles, look into the distance on a count of 1-6. Repeat 1-2 times.
Answer the questions 1. What is the area of the world's oceans? 2. Name the parts of the world's oceans. 3. Name the largest, deepest and most ancient of the oceans. 4. Name the youngest and warmest among the world’s oceans. 5. Name the second largest ocean on Earth. 6. Name the smallest ocean on Earth by area. 7. What is the Southern Ocean? 8. What are marginal seas? Give an example of marginal seas. Show them on the map. 9. What are inland seas? Give an example of inland seas. Show them on the map. 10. What is a bay? What is a strait? What straits and bays do you know? Show them on the map.
Homework § 24, c On the contour map of the hemispheres, label all the oceans, seas, bays, straits, islands and archipelagos indicated in the paragraph
Hydrosphere is the watery shell of the Earth. It includes all non-chemically bound water, regardless of its state of aggregation. Most of the hydrosphere is made up of the waters of the World Ocean (96.6%), 1.7% is groundwater, approximately the same amount is accounted for by glaciers and permanent snow, and less than 0.01% is land surface water (rivers, lakes, swamps). A small amount of water is found in the atmosphere and is part of all living things. The hydrosphere is one. Its unity is in the common origin of all natural waters from the Earth’s mantle, in the unity of their development, in spatial continuity, in the interconnection of all natural waters in the system of the World Water Cycle in nature.
The global water cycle is the process of continuous movement of water under the influence of solar energy and gravity, covering the hydrosphere, atmosphere, lithosphere and living organisms. The water cycle consists of evaporation from the surface of the World Ocean, the transfer of water vapor by air currents, its condensation in the atmosphere, precipitation, its infiltration and surface and underground flow of land into the Ocean. In the process of the World Water Cycle in nature, it is gradually renewed in all parts of the hydrosphere. This process requires different periods of time: groundwater is renewed over hundreds, thousands and millions of years, polar glaciers - over 8 - 15 thousand years, the World Ocean over 2.5 - 3 thousand years, closed, drainless lakes - 200 - 300 years , flowing waters for several years, and rivers for 12 - 14 days.
World Ocean. The world ocean refers to the oceans of the Earth:
The Pacific Ocean is the largest and deepest ocean on Earth;
The Atlantic is the second largest ocean on Earth;
The Indian Ocean - its area could easily fit three continents. Almost entirely located in the southern hemisphere;
The Arctic is the smallest, coldest ocean on our planet.
South ocean.
The volume of water in the World Ocean is 1,338,000,000 km. cubic, its average depth is 3700 m, maximum - 11022 m.
The waters of the World Ocean have certain properties, and one of them is the salinity of the waters.
Almost all substances known on Earth are dissolved in ocean water, but in varying quantities.
Most of them are difficult to detect due to their small numbers. The main part of the salts dissolved in ocean water are chlorides (89%) and sulfates (almost 11%), significantly less carbonates (0.5%). Table salt (NaCl) gives water a salty taste, magnesium salts (Mg,Cl) give it a bitter taste. The total amount of all salts dissolved in water determines the salinity of the water. It is measured in thousandths - ppm.
The average salinity of the World Ocean is about 35 ppm, i.e. Each kilogram of water contains an average of 35 grams of salts. Salinity depends primarily on the ratio of precipitation and evaporation. River waters and water from melting ice reduce the salinity. In the open ocean, the distribution of salinity is zonal. In equatorial latitudes, where there is a lot of precipitation, it is low, in tropical latitudes it is high, due to high evaporation and low precipitation. In temperate and polar latitudes, salinity decreases again.
Ocean water has a high dissolving capacity, so the Ocean absorbs and releases huge amounts of gases. Oxygen, nitrogen, carbon dioxide, hydrogen sulfide, ammonia and methane are dissolved in the water of oceans and seas.
Water temperature. It depends on latitude and is distributed zonally on its surface. Zoning is disrupted by ocean currents, the influence of land, and constant winds. The highest average annual water temperatures (27 - 28 degrees) are observed in equatorial latitudes. With increasing latitude, the amount of solar radiation decreases, and the temperature of the waters of the World Ocean drops to 0 degrees and even lower in the polar regions. The average water temperature in the World Ocean is 17.5 degrees.
Temperature also changes with depth. At the bottom it does not exceed a temperature of 2 degrees. Water has a high heat capacity, so a huge amount of heat accumulates in the ocean. Only the upper 10-meter layer of ocean water contains more heat than the entire atmosphere. The freezing point of water with an average salinity of 35 ppm is 1.8 degrees below 0.
Movement of Ocean waters. Ocean water is in constant motion. The movement of water occurs not only on the surface, but also with depth, to the very bottom layers. The main cause of disturbances on the surface of the World Ocean is wind. As a result of underwater earthquakes and volcanic eruptions, seismic waves - tsunamis - arise. When these waves hit the shore, they cause catastrophic destruction, claiming thousands of lives.
Under the influence of the gravitational forces of the Moon and the Sun, periodic fluctuations in the level of the Ocean occur - tidal movements of ocean waters.
Currents. Ocean currents are caused by wind (wind or drift); arise due to different heights of the water level (runoff) and different densities (density). According to the properties of water, there are currents: cold (for example, the West Wind Current, Labrador Current) and warm (North Atlantic, Gulf Stream).
Organic world of the Ocean. This world is very diverse. The ocean is home to about 160 thousand species of animals and more than 10 thousand species of algae. Based on the type of habitat and lifestyle, marine organisms are grouped into three groups:
plankton - passively moving single-celled algae (phytoplankton) and animals (zooplankton) - single-celled crustaceans, jellyfish;
nekton - actively moving animals (fish, cetaceans, turtles, cephalopods, etc.);
benthos - organisms living on the bottom (brown and red algae, mollusks, crustaceans, starfish, etc.).
The distribution of life in the surface layer of ocean water has a clearly expressed zonal character. Temperate latitudes are most productive.
Resources of the World Ocean. There are biological, mineral and energy resources. In terms of scale of use and importance, nekton occupies the leading place. The predominant part of its biomass is represented by fish. The water of the World Ocean is called “liquid ore”. On an industrial scale, only sodium, chlorine, magnesium and bromine are extracted from it. Desalination of seawater is becoming increasingly important. The ocean floor is rich in mineral resources. They include: ore deposits of coal, iron ore, oil and gas. There are nodules of manganese, phosphorites, and diamond placers.