The highest salinity of water in the ocean is observed. What is the salinity of water? Salinity of the waters of the oceans
World Ocean- This is a combination of four oceans of our planet: the Pacific, Atlantic, Indian and Arctic. The world ocean washes the shores of all continents, but unlike land, it is a single space. The ocean occupies 71% of the surface of our planet (about 360 million km 2).
The bottom of the oceans is composed of a three-layer oceanic-type crust. In contrast to the continental crust, it has a smaller thickness - 5-10 km. In the relief of the bottom of the oceans, it is customary to distinguish the following components: the underwater margins of the continents, transition zone, bed of the ocean.
In contrast to the continents, the effect of external relief-forming processes is much less pronounced in the oceans. As a result, the ocean floor is more homogeneous than the earth's surface.
Average ocean depths are about 3700 m, while in its open parts the smallest depths are noted in the areas of mid-ocean ridges, and the maximum are confined to deep-sea trenches.
Water masses of the oceans characterized by a number of properties, the main of which are the temperature and salinity of the waters.
World Ocean water temperature changes both horizontally and vertically. The temperature of the surface of the waters varies zonal, decreasing in the direction from the equator to the poles. This is due to the fact that the earth's surface near the equator, due to the more sheer fall of the sun's rays, receives large quantity solar heat. The temperature of the surface waters of the ocean near the equator is 25˚-28˚. In the area of the North Pole, the water surface temperature can drop to 0˚ or even slightly lower (-1.3˚), as salt water freezes at low temperatures.
With depth, the temperature of the waters in the World Ocean decreases due to the fact that the sun's rays are not able to heat the entire water column.
Average salinity of the oceans- 35%, that is, 35 g of salts are dissolved in 1 liter of ocean water. The salty taste of sea water is due to the presence of chlorides, and the bitter taste is due to magnesium salts. The salinity index of surface waters is determined by the ratio of the amount of atmospheric precipitation and the amount of evaporation. A large influx of atmospheric moisture distributes water, significant evaporation, on the contrary, increases salinity, since salts do not evaporate with water. The highest salinity of the waters is characteristic of tropical latitudes, and the Red Sea is generally the most saline sea in the world's oceans.
The waters of the oceans are in constant motion. The main types of water dynamics include waves (wind and tsunamis), currents, ebbs and flows.
Surface currents can occur for various reasons. In accordance with this, the types of flows are distinguished: wind (drift); with uneven distributions of temperatures or salinity (density); tidal due to the attraction of the moon; gradient when changing atmospheric pressure; stock; compensation at low tide of the neighboring water mass, etc.
However main reason The occurrence of ocean currents are the winds of the general circulation of the atmosphere: trade winds, westerly transport, and others. In each of the hemispheres, the system of currents forms a kind of giant "eight".
According to the temperature, the currents are divided into warm and cold. In this case, the absolute temperature of the water does not play a role in this case. The temperature of the flowing water relative to the surrounding waters is important. That is, a warm current is a powerful jet of warmer water among colder water. The general direction of warm currents is from the equator to the poles, cold ones, on the contrary, are from the poles to the equator. Ocean currents have a significant impact on the climate of the coastal areas they wash. Thus, cold currents, preventing the rise of air, contribute to a decrease in the amount of precipitation. On the subtropical coasts washed by cold currents (Peruvian, Bengal), coastal deserts are formed (Atacama, Namib).
World Ocean is the birthplace of life on earth. The conditions for the existence of living organisms in water are more favorable than on land. There are no sharp fluctuations in temperature, the surrounding water supports the body of the organism in space. The total number of species of living organisms in the World Ocean is approaching 160 thousand. At the same time, most of the biomass of the ocean, in contrast to land, is made up of animals.
The oceans are of great importance in human economic activity. The ocean is a source of natural resources. The main thing is biological resources: fish, seafood, sea animals, shells, pearls, etc. In addition to biological, they began to actively use mineral resources, primarily oil and gas from shelf zones. Huge potential energy resources. In addition, the most important transport routes serving world trade pass through the ocean. The coasts of the oceans are widely used for recreational purposes.
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Includes all the seas and oceans of the Earth. It occupies about 70% of the planet's surface, it contains 96% of all water on the planet. The world ocean consists of four oceans: Pacific, Atlantic, Indian and Arctic.
The size of the Pacific oceans - 179 million km2, Atlantic - 91.6 million km2 Indian - 76.2 million km2, Arctic - 14.75 million km2
The boundaries between the oceans, as well as the boundaries of the seas within the oceans, are drawn rather conventionally. They are determined by land areas that delimit the water space, internal currents, differences in temperature and salinity.
The seas are divided into internal and marginal. The inland seas protrude deep enough into the land (for example,), and the marginal seas adjoin the land at one edge (for example, the North, Japan).
Pacific Ocean
The Pacific is the largest of the oceans. It is located in both the northern and southern hemispheres. In the east, its border is the coast of the North and, in the west - the coast and, in the south - Antarctica. He owns 20 seas and more than 10,000 islands.
Since the Pacific takes over almost all but the coldest,
it has a varied climate. over the ocean fluctuates from +30°
The water temperature in the Atlantic Ocean ranges from -1°С to +26°С, the average water temperature is +16°С.
The average salinity of the Atlantic Ocean is 35%.
The organic world of the Atlantic Ocean is rich in green plants and plankton.
Indian Ocean
Most of the Indian Ocean is located in warm latitudes, humid monsoons dominate here, which determine the climate of East Asian countries. The southern edge of the Indian Ocean is very cold.
The currents of the Indian Ocean change direction depending on the direction of the monsoons. The most significant currents are the Monsoon, Tradewind and.
The Indian Ocean is diverse, there are several ridges, between which relatively deep basins are located. The deepest point of the Indian Ocean is the Java Trench, 7 km 709 m.
The water temperature in the Indian Ocean ranges from -1°C off the coast of Antarctica to +30°C, the average water temperature is +18°C.
The average salinity of the Indian Ocean is 35%.
Arctic Ocean
Most of the Arctic Ocean is covered with a layer of ice - in winter it is almost 90% of the ocean's surface. Only near the coast ice freezes to land, while most of the ice drifts. Drifting ice is called "pack".
The ocean is completely located in the northern latitudes, it has a cold climate.
A number of large currents are observed in the Arctic Ocean: a transarctic current passes along the north of Russia, as a result of interaction with the warmer waters of the Atlantic Ocean, a current is born.
The relief of the Arctic Ocean is characterized by a developed shelf, especially off the coast of Eurasia.
Water under ice always has a negative temperature: -1.5 - -1°C. In summer, the water in the seas of the Arctic Ocean reaches +5 - +7 °С. The salinity of the ocean water is significantly reduced in summer due to the melting of ice and, this applies to the Eurasian part of the ocean, full-flowing Siberian rivers. So in winter, salinity in different parts is 31-34% o, in summer off the coast of Siberia it can be up to 20% o.
Maritime transport is an essential element international trade. Countries such as, and others, cut off from the mainland and not having enough of their own resources, are entirely dependent on. A potential environmental hazard is associated with this: the wreck of a ship carrying oil, fuel oil, coal and others causes serious damage.
Seventy percent of the surface of our planet is covered with water - most of it is in the oceans. The waters of the World Ocean are heterogeneous in composition and have a bitter-salty taste. Not every parent can answer the child's question: "Why does sea water taste so good?" What determines the amount of salt? Exist different points perspective on this.
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What determines the salinity of water
AT different times salinity is not the same in different parts of the hydrosphere. Several factors influence its change:
- ice formation;
- evaporation;
- precipitation;
- currents;
- river flow;
- melting ice.
While the water from the surface of the ocean evaporates, the salt does not erode and remains. Her concentration is increasing. The freezing process has a similar effect. Glaciers contain the largest supply of fresh water on the planet. The salinity of the oceans during their formation increases.
The opposite effect is characterized by the melting of glaciers, in which the salt content decreases. Salt also comes from rivers flowing into the ocean and precipitation. The closer to the bottom, the less salinity. Cold currents reduce salinity, warm currents increase it.
Location
According to experts, The concentration of salt in the seas depends on their location. Closer to the northern regions, the concentration increases, to the south it decreases. However, the concentration of salt in the oceans is always greater than in the seas, and location does not have any effect on this. This fact is not explained.
Salinity is due to the presence of magnesium and sodium. One of the options for explaining the different concentrations is the presence of certain land areas enriched in deposits of such components. However, such an explanation is not very plausible, if we take into account the sea currents. Thanks to them, over time, the salt level should stabilize throughout the volume.
World Ocean
The salinity of the ocean depends on the geographical latitude, the proximity of rivers, the climatic features of objects etc. Its average value according to the measurement is 35 ppm.
Near the Antarctic and the Arctic in cold areas, the concentration is less, but in winter, during the formation of ice, the amount of salt increases. Therefore, the water in the Arctic Ocean is the least salty, and in the Indian Ocean, the concentration of salt is the highest.
In the Atlantic and Pacific oceans, the concentration of salt is approximately the same, which decreases in the equatorial zone and, conversely, increases in tropical and subtropical regions. Some cold and warm currents balance each other. For example, the salty Labrador Current and the unsalted Gulf Stream.
Interesting to know: How many exist on Earth?
Why are the oceans salty
There are different points of view that reveal the essence of the presence of salt in the ocean. Scientists believe that the reason is the ability of water masses to destroy the rock, leaching easily soluble elements from it. This process is ongoing. Salt saturates the seas and gives a bitter taste.
However, there are diametrically opposed opinions on this issue:
Volcanic activity decreased over time, and the atmosphere cleared of vapor. Acid rain fell less and less, and about 500 years ago, the composition of the ocean water surface stabilized and became what we know it today. Carbonates, which enter the ocean with river water, for marine organisms are excellent building materials.
geography grade 7
World Ocean
The share of the waters of the World Ocean in the composition of the hydrosphere is ... (%)
97
The main source of atmospheric moisture is...
water vapor
World Ocean
surface of rivers and lakes
green plants
The waters of the oceans have ... origin
biological
atmospheric
space
mantle
Salt water, compared to fresh water, has...
lower freezing and boiling points
lower freezing point and higher boiling point
higher freezing point and lower boiling point
elevated freezing and boiling points
The dependence of ocean water temperature on geographic latitude is most noticeable ...
at the surface of the water
at a depth of 500 m
at a depth of 1000 m
at the bottom
The highest salinity of ocean waters is typical for ... latitudes
equatorial
tropical
moderate
arctic
The lowest salinity of ocean waters is typical for ... latitudes
equatorial and tropical
tropical and subtropical
subtropical and temperate
temperate and equatorial
The saltiest of the seas belongs to ... the ocean
Quiet
the Arctic
Atlantic
Indian
The highest salinity of the waters of the oceans is observed where the amount of precipitation ...
exceeds evaporation
equal to evaporation
below evaporation
If we move in the direction from the equator to the poles, then the temperature of the bottom waters ...
rises
does not change
going down
Salt water freezes at...
positive
zero
negative
With depth, the temperature of the waters of the World Ocean changes as follows ...
first increases, then does not change
first it goes down, then it goes up
first decreases, then does not change
does not change
The temperature of the North Atlantic Current, compared to the cold Canary, ...
above
the same
below
The main cause of surface currents in the oceans is ...
underwater earthquakes
constant winds
surface slope
differences in water temperature
The temperature of the water in the oceans is determined by...
ambient temperature
angle of incidence of the sun
salinity
Icebergs in the oceans penetrate closer to the equator in ... hemisphere
northern
southern
The most powerful current in the world's oceans is...
Gulfstream
Labrador
Western winds
Kuroshio
Among the inhabitants of the water column is actively moving ...
plankton
nekton
benthos
The most populated part of the oceans is...
continental slope
shelf
deep sea trenches
bed
Of the types of economic activity, the least harm to the nature of the World Ocean is caused by ...
offshore oil and gas production
maritime shipping
fishing
construction of tide stations
A1. What determines the salinity of ocean water?
on the amount of precipitation
from evaporation
from the inflow of river waters
for all of the above reasons.
A2. Temperature of surface ocean waters:
everywhere the same
depends on latitude
only changes with depth
varies with both breadth and depth
A3. Which European navigator's expedition crossed the Pacific Ocean for the first time?
F. Magellan
J. Cook
I.F. Kruzenshtern
H. Columba
A4. What winds dominate the Pacific Northwest?
trade winds
typhoons
monsoons
Western
A5. Specify the deepest place in the Pacific.
Java Trench
Kuril Trench
Mariana Trench
Philippine Trench
A6. Why do tsunamis often occur in the Pacific Ocean?
the boundary of the lithospheric plates runs along the edges of the ocean
waves cause the attraction of the earth
tsunamis cause storm winds
in the ocean there is a system of powerful currents
A7. Which island is NOT in the Indian Ocean?
Madagascar
Sri Lanka
Taiwan
Socotra
A8. What part of the Indian Ocean is dominated by monsoons?
in northern
in the south
in western
in the eastern
A9. Specify the cold current of the Atlantic Ocean.
Gulfstream
brazilian
Canarian
Norwegian
A10. In which part of the Atlantic Ocean is oil produced?
in the Gulf of Mexico
in the Bay of Biscay
in the Baltic Sea
in the mediterranean
A11. Who drifted on the Fram in the Arctic Ocean?
F. Nansen
O.Yu. Schmidt
G.Ya. Sedov
V.Barents
A12. Specify erroneous statement.
The Arctic Ocean has a harsh climate.
The Arctic Ocean is the shallowest.
The seas of the Northern Ocean are internal and only one is external.
In the center is the North Pole.
1. The area of which ocean is 178.6 million km2?
A) Atlantic B) the Arctic;
B) Quiet; D) Indian.
2. What ocean washes the shores of 4 continents?
A) Atlantic B) South
B) Indian; D) Quiet.
3. There is a current in the Atlantic Ocean:
A) Kuroshio B) Gulf Stream;
B) Somali.
4. In the Pacific Ocean is the deepest depression on the planet (11022m):
A) the Sunda Trench; B) the Greenland Sea;
B) the Mariana Trench.
5. -10C; -20C is the average temperature in the surface layer:
A) the Arctic Ocean B) the Pacific Ocean;
B) the Indian Ocean.
6. Warm Mozambique Current is part of:
A) the Arctic Ocean B) the Atlantic Ocean;
B) the Indian Ocean.
7. Which ocean has no connection with the Arctic Ocean?
A) Quiet B) Atlantic;
B) Indian.
8. About the Pacific Ocean, you can say:
A) It is the deepest, most ancient, has many volcanoes, a huge supply of heat;
B It stretched from the subarctic latitudes to Antarctica, according to the theory of lithospheric plates, it is relatively young;
C) the most shallow, occupies the space of the North Pole.
9. Which ocean basin includes the saltiest sea in the world (Red Sea 42‰)?
A) Atlantic B) Indian;
B) Quiet.
10. The climate of this ocean is varied, as it lies in all climatic zones:
A) Atlantic B) Quiet;
B) Indian.
11. Most high degree oil pollution is due to:
A) Quiet B) Indian;
B) Atlantic.
12. In which ocean is the sea "without shores" (Sargasso)?
A) Quiet B) Indian;
B) Atlantic.
13. What oceans does the Panama Canal connect? (select 2 oceans)
A) Quiet B) Indian;
14. Which ocean basin does the Mediterranean Sea belong to?
A) Quiet B) Indian;
B) Atlantic. D) the Arctic.
15. What ocean is it in anomalous zone called "Bermuda" triangle"?
A) Quiet B) South;
B) Atlantic. D) the Arctic.
16. What ocean washes the shores of the coldest continent on the planet?
A) Quiet B) South;
B) Atlantic. D) the Arctic.
17. What is the smallest ocean in terms of area?
A) Quiet B) Indian;
B) Atlantic. D) the Arctic.
18. What ocean is the island of Madagascar in?
A) Quiet B) Indian;
B) Atlantic. D) the Arctic.
19. What ocean was F. Magellan the first European to reach and give it a name?
A) Quiet B) Indian;
B) Atlantic. D) the Arctic.
20. On what ocean did H. Columbus make his journey to India, and discovered the New World?
A) Quiet B) Indian;
B) Atlantic. D) the Arctic.
Answers: 1.B; 2.G; 3.B; 4.B; 5.A; 6.B; 7.B; 8.A; 9.A; 10.A; 11.B; 12.B; 13..A, B; 14.B; 15.B; 16.B; 17.G; 18.B; 19.A; 20.B.
Water White Sea less desalinated due to freer communication with the ocean. In its basin, the salinity of surface waters is 24-26% o, in the Gorlo 28-30% o, and in the bays it is much lower and fluctuates strongly under the influence of surge and tidal level fluctuations. Sometimes in the Dvina, Kandalaksha and Onega bays, almost fresh water is replaced by water with a salinity of 20-25%o.[ ...]
The waters of the inland seas, located in tropical latitudes, where there is little precipitation, few rivers, and high evaporation, are more saline than oceanic waters. These are the Mediterranean, Red and Persian Gulf seas. The Mediterranean Sea, characterized by a negative freshwater balance and difficult water exchange with the ocean through the narrow Strait of Gibraltar, has a salinity of surface waters higher than that of the ocean. From the Strait of Gibraltar to about. Sicily it is 37-38%o, in the eastern part of the sea 39%0 and more.[ ...]
The salinity of the surface waters of the seas often differs significantly from the salinity of oceanic waters (sometimes it exceeds it, sometimes it turns out to be less). These differences are determined by the conditions of water exchange between the seas and the ocean, the influence of climate and land water runoff. The salinity of the surface waters of the seas, the water exchange of which occurs more or less freely, is close to oceanic. With difficult water exchange, the differences can be significant.[ ...]
The salinity of the Ocean is not a constant value. It depends on the climate (the ratio of precipitation and evaporation from the surface of the Ocean), the formation or melting of ice, sea currents, near the continents, on the influx of fresh river waters. In the open Ocean, salinity ranges from 32-38%; in the marginal and Mediterranean seas, its fluctuations are much greater. Experiencing fluctuations in the amount of dissolved salts, sea water is distinguished by the exceptional constancy of their ratio to each other. The ratio of solutes is maintained in various parts Ocean, on its surface and in deep layers. Based on this regularity, a method has been built for determining the salinity of sea waters by the amount of any one element contained in them, most often chlorine.[ ...]
The ocean is the main acceptor and accumulator of solar energy, since water has a high heat capacity. The water shell (hydrosphere) includes: salty waters of the World Ocean and inland seas; fresh waters of the land, concentrated in mountain ice, rivers, lakes, swamps. Consider environmental characteristics aquatic environment.[ ...]
The ocean belongs to the group of saline waters, while sea waters are sometimes brines (for example, the Red Sea) or semi-solid (for example, the Sea of \u200b\u200bAzov), that is, they have a sharply different concentration, less or more than the average, little changing in composition ocean water. The transition is sometimes quite abrupt.[ ...]
In the ocean, the difference in temperature and salinity is small, but the described process enhances the vertical mixing of water.[ ...]
The volume of water on the globe is measured at 1386 million km3, which means that each of us has 350 million m3 of water, which is equal to ten reservoirs such as Mozhayskoye on the river. Moscow. Unfortunately, there is every reason for this. After all, a person needs not just any water, but only fresh water, that is, containing no more than 1 g of salts per 1 liter, and at the same time it must be of high quality. It is known that 97.5% of the water is concentrated in the World Ocean, the salinity of which is 35%a, or 35 g/l. Fresh water accounts for only 2.5%, while more than 2/3 of it is conserved in glaciers and snowfields, and only 0.32% falls on lakes and rivers. The most important and used for a variety of needs, river waters account for only 0.0002% of the total water reserves [Lvovich, 1974].[ ...]
In the Pacific Ocean, to the north of the subpolar front, the North Pacific intermediate water is formed with a salinity of 33.6 to 34.6% o, which then spreads to the south at depths of 500-1500 m.[ ...]
In all oceans and seas, there is a constant ratio of salts that make up the water. The total mass of salts in sea water is 48-1015 tons, or about 3.5% of the total mass of ocean water. This amount of salts would be enough to form a salt layer up to 45 m thick over the entire surface of our planet. For every 1000 g of ocean water, there are 35 g of salts, i.e. the salinity of the oceans averages 35%.[ ...]
The world ocean is heterogeneous both in salinity and in temperature. It is possible to distinguish isometric regions, layers and the thinnest layers in it. The most heat ocean water (404°C) was recorded at a hot spring 480 km off the west coast of America. Water heated to such a temperature did not turn into steam, since the source was located at a considerable depth under conditions of high pressure. The cleanest water in the world is found in the Weddell Sea in Antarctica. Its transparency corresponds to the transparency of distilled water. At the same time, the waters of the World Ocean are in constant motion, their temperature and currents affect the state of air masses and determine the weather and climatic conditions in the surrounding areas.[ ...]
The area of salt waters (seas, oceans) is just over 70% of the Earth's surface. Fresh waters (less than 1 g/l of salt) make up slightly less than 6% of the reserves, or, in absolute terms, 90 million km3. But the whole trouble is that only about 3% of fresh water is easily accessible reserves such as rivers, lakes and reservoirs, the rest is glaciers, groundwater. Thus, we can only use about 2.5 million km3 of water. But part of this water is polluted and unfit for consumption.[ ...]
The average salinity of the waters on the surface of various oceans is not the same: the Atlantic 35.4% o, the Pacific 34.9 ° / oo, the Indian 34.8% o. 10 shows the average salinity on the surface of the oceans in the southern and northern hemispheres.[ ...]
The World Ocean is the water shell of the Earth, with the exception of water bodies on land and the glaciers of Antarctica, Greenland, polar archipelagos and mountain peaks. The oceans are divided into four main parts - Pacific, Atlantic, Indian, Arctic oceans. The waters of the World Ocean, going into the land, form seas and bays. The seas are relatively isolated parts of the ocean (for example, the Black, Baltic, etc.), and the bays do not protrude into the land as much as the seas, and in terms of the properties of the waters differ little from the World Ocean. In the seas, the salinity of water can be higher than oceanic (35%), as, for example, in the Red Sea, up to 40%, or lower, as in the Baltic Sea, from 3 to 20%.[ ...]
Usually in water there are various impurities of organic and inorganic origin. Distinguish between salt and fresh water. The main mass of water on our planet is salt water, which forms the salty World Ocean and most of the mineralized underground waters of deep occurrence (1.5 ... 2 km).[ ...]
Fronts in the ocean arise due to the influence of a variety of mechanisms. Sometimes they look very distinct in the fields of temperature and salinity, while in the density field they are almost not expressed. Sharp changes in the properties at the fronts turn out to be significant due to the fact that they affect the dynamics. A review of satellite observations over temperature fronts is made in . The main climatic frontal zones (where fronts are most often recorded) in the northern part of the Pacific Ocean are shown in fig. 13.11; they were discussed in Rodin's work. One of the important types of fronts is associated with the Ekman convergence in the surface layer. Examples of such fronts are subtropical fronts, which are observed at latitudes from 30 ° N. sh. up to 40°S sh. Their changes associated with fluctuations in the Ekman divergence were studied in . The second type of fronts is formed at the boundary of water masses (see). Such a front separates, for example, the waters of the subarctic and subtropical gyres. In the northern part of the Pacific Ocean (Fig. 13.11), this front is located at a latitude of 42 ° N. sh. It was formed at the meeting place of the cold, equator-directed, Oyashio current with the warm current of the polar direction - Kuroshio. On the surface, this front is well expressed in the sections of temperature and salinity, but in the density field it is hardly noticeable.[ ...]
In the World Ocean, physical, chemical, biological and other processes continuously occur that change the salinity, i.e., reduce or increase the concentration of the solution. However, regardless of the absolute concentration of the solution, the quantitative ratios between the main ions remain constant. Therefore, it is sufficient to know the concentration of one of the components in order to determine the rest. To determine salinity, the sum of ions Cl + Br + I, called chlorine content, is used, the concentration of which in sea water is the highest.[ ...]
The bulk of the water is concentrated in the oceans. Its average depth is more than 4000 m, it covers an area equal to 361 million km2 (71% of the earth's surface), and is characterized by high salinity (3.5%). Continental water bodies cover about 5% of the Earth's area. Of these, surface waters (lakes, rivers, swamps, etc.) account for a very small part (0.2%), glaciers - 1.7%. Groundwater makes up about 4% of the total volume of the hydrosphere. The entire planetary water supply reaches 1450 million km.[ ...]
Sea water contains 89% chlorides, 10% sulfates and 0.2% carbonates, while fresh water contains 80% carbonates, 13% sulfates and 7% chlorides. The water of closed seas, such as the Caspian, is not typically marine. It is significantly less salty and contains three times more carbonates than the water of the oceans. According to modern concepts, the salinity of the water of the seas and oceans is "primary", which did not change during geological periods.[ ...]
Processes that change oceanological characteristics are continuously taking place in the World Ocean. As a result of uneven changes in these characteristics, their horizontal and vertical gradients arise, simultaneously with which processes develop, aimed at equalizing the properties of water masses, at the destruction of gradients. These are processes of vertical and horizontal exchange, i.e. mixing. Changes in temperature, salinity, and density with depth are associated with vertical gradients of these values. The gradient of each of these values can be positive or negative. If the density gradient is positive (density increases with depth), the water masses are in a stable state; if it is negative, they are unstable: light waters tend to rise, and heavy waters sink. An increase in density under the influence of a decrease in temperature or an increase in salinity on the surface causes the upper layers of water to sink and the lower ones to rise. As a result, the density of water in the upper, mixed layer decreases, while in the underlying layer it increases. In the water layer located above the shock layer, the processes of water mixing occur most intensively; this layer is called the active layer. Below the water jump layer, they become stable, since here the temperature decreases with depth, and salinity and density increase.[ ...]
Salinity fluctuations over time are insignificant. Annual fluctuations in the open parts of the oceans do not exceed 1% o, at a depth of 1500-2000 m salinity is almost unchanged (differences of 0.02-0.04% o). Significant fluctuations in salinity are observed in coastal areas, where fresh water inflow is more intense in spring, as well as in polar regions due to the processes of freezing and melting of ice.[ ...]
Fresh water reserves make up less than 2% of water resources. The average salinity of the waters of the World Ocean is 3.5 g / l (in the oceans 48-1015 tons of salt), drinking water should contain no more than 0.5 g / l, plants die from water containing 2.5 g / l of salt. Approximately 3/4 of the world's fresh water reserves are located in the ice of Antarctica, the Arctic, and glacial mountains. About 35 thous. sea ice and icebergs are included in the volume of the oceans. But 10-15 thousand icebergs break off annually only from the coast of the Arctic and Greenland. The annual river runoff is estimated at 41,000 km'. In Europe and Asia, where 70% of the population lives, only 39% of the world's river water reserves are concentrated. The world's most abundant lake Baikal (23 thousand km3) contains 20% of the world's surface fresh water reserves. Russia has the world's largest underground water storage - the West Siberian artesian basin with an area of 3 million km2, which is almost 8 times the area of the Baltic Sea.[ ...]
If the density of sea water is constant, then the ocean is said to be homogeneous. If the vertical density distribution depends only on pressure, then one speaks of a barotropic ocean. If the density of sea water is determined by temperature, salinity and pressure, then the ocean is considered baroclinic.[ ...]
For every 1000 g of ocean water, there are 35 g of salts, i.e. the salinity of the oceans averages 35%o (ppm).[ ...]
According to modern concepts, the salinity of the water of the seas and oceans is "primary", not changing during geological periods. Thus, the question of how water appeared on Earth requires study and clarification.[ ...]
Being an excellent solvent, water contains dissolved salts, gases, organic substances, the content of which in water can vary over a wide range. If the salt concentration is less than 1 g / kg, the water is considered fresh, with a salt concentration of up to 25 g / kg - brackish, and at a higher concentration - salty. In the ocean, the concentration of salts is about 35 g / kg, in fresh lakes, rivers 5-1000 mg / kg. Sea water is a multicomponent system that includes water molecules, anions and cations of salts, as well as many impurities. Good mixing of sea waters leads to equalization of the content of salt components in different parts of the World Ocean, and therefore one can speak of the constancy of the salt composition of ocean waters. To characterize salinity, the value S is used - salinity, which determines in grams the mass of dissolved solid contained in 1 kg of sea water, provided that bromine and iodine are replaced by an equivalent content of chlorine, all carbonic salts are converted into oxides, all organic substances are burned at a temperature of 480 ° C. This definition of salinity goes back to the previously accepted definition of salinity by chlorine content by titrating sea water. Salinity is measured in thousandths - ppm (% o). The constancy of the salt composition of sea water makes it possible to determine salinity by the content of one component.[ ...]
Similar expressions can be written for the salinity and density of sea water. The first member from right side- a class of phenomena constituting the subject of classical oceanography; the second term is heterogeneities related to the phenomenon of fine thermohaline structure; the third term is microturbulence according to Reynolds; tr - values of spatial and temporal scales delimiting the structural elements of water masses, due to the thin layered structure and turbulence. As a rule, the irregularity of vertical salinity profiles is greater than the irregularity of temperature distributions. Sea water has another interesting property. If in the atmosphere the rates of molecular diffusion of heat and moisture are almost the same, then the rates of diffusion of heat and salt in the ocean differ by two orders of magnitude (K = 1.4 10 3 cm2/s, 1 = 1.04 10 5 cm2/s), which leads to such a phenomenon as differential-diffusion convection, which is one of the mechanisms that determine the formation of a fine thermohaline structure of sea waters.[ ...]
Since information about the fields of temperature and salinity makes it possible to calculate the currents only relative to some given level, the velocities of stationary geostrophic currents in the ocean cannot be determined absolutely accurately. Therefore, it is also impossible to find the exact values of transfers and compare them with calculations using the Sverdrup ratio. However, some comparisons can still be made. So, for example, in Fig. 12.7.6 shows the currents of the North Atlantic at a depth of 100 m relative to the currents at a depth of 1500 m. If we assume that the last currents are relatively weak, then Fig. 12.7.6 can be viewed as a picture of near-surface geostrophic currents. It shows many conspicuous coincidences with Fig. 12.7, a, which indicates that the effect of wind largely explains the pattern of surface circulation. On the other hand, significant differences, which can also be seen in these figures, indicate the importance of other factors, such as buoyancy forces. Worthington's calculations, in particular, show that the sinking of the waters in the Greenland Sea carries large masses of surface water there from the North Atlantic, and this significantly affects the overall circulation pattern.[ ...]
The uneven distribution of temperature, as well as salinity, is mainly created by mixing processes and sea currents. In the surface layers, within the active layer of the sea, the stratification of water masses is associated mainly with the processes of vertical exchange, and at depth the heterogeneity of oceanological characteristics is associated with the general circulation of the waters of the World Ocean. The heterogeneity of the waters of the oceans and seas, associated with the processes of vertical and horizontal exchange, determines the presence of intermediate cold or warm layers with reduced or elevated temperatures. These layers can be of convective (due to mixing) and advective origin. The latter are associated with the delivery (askes), i.e., horizontal intrusion, of water masses carried from outside by currents. An example is the presence of warm Atlantic waters in the entire central part of the Arctic Ocean, which can be traced at depths from 150–250 to 800–900 m. contacts arise? vertical gradients of oceanographic characteristics. The transition layer, in which the gradients of temperature, salinity, density and other properties are large, is called the jump layer. These layers may be temporary, seasonal, or permanent in the active layer and on its boundary with deep waters. Deep-sea observations in various regions of the World Ocean (Fig. 14) show that in open regions, except for the polar regions, the temperature changes noticeably from the surface to a depth of 300-400 m, then up to 1500 m the changes are very insignificant, and from 1500 m it almost does not change. At 400-450 m the temperature is 10-12° C, at 1000 m 4-7° C, at 2000 m 2.5-4° C and from a depth of 3000 m it is about 1-2° C.[ ...]
If you do not touch dirty drains and poisonous plums, then since ancient times the waters are divided into salty and fresh. Salt waters, in comparison with fresh waters, contain an increased concentration of salts, primarily sodium. They are not suitable for drinking and industrial use, but are excellent for swimming and water transport. The salt composition of saline waters in different water bodies varies quite a lot: for example, in the shallow Gulf of Finland, the waters are less saline than in the Black Sea, and in the oceans, the salinity is much higher. I want to remind you that salt water is not necessarily sea water. There are known basins with exceptionally salty waters that have no connection with the sea, such as the Dead Sea in Palestine and the salt lake Baskunchak.[ ...]
Ripe lagenaria fruits are so light that they do not sink in salt water and are able to swim in the ocean for a long time without damage and without loss of seed germination. Since ancient times, accidentally falling into the Atlantic Ocean, the fruits of lagenaria, picked up by ocean currents, sailed from the coast West Africa in Brazil or across the Pacific Ocean came from Southeast Asia to Peru, and from there the ancient inhabitants of South and North America spread throughout the continent.[ ...]
All of these factors determine the regime and changes in the salinity of the oceans and seas. Since salinity is the most conservative, established property of the waters of the World Ocean, we can also talk about the balance of salts. The incoming part of the salt balance is composed of the inflow of salts: a) with continental runoff, b) with atmospheric precipitation, c) from the Earth's cedar in the form of mantle degassing products, d) during the dissolution of rocks at the bottom of the oceans and seas.[ ...]
Hydrosphere - the water shell of the Earth, including oceans, seas, rivers, lakes, groundwater and glaciers, snow cover, as well as water vapor in the atmosphere. The Earth's hydrosphere is 94% represented by salt waters of the oceans and seas, more than 75% of all fresh water is conserved in the polar caps of the Arctic and Antarctica (Table 6.1).[ ...]
The salinity of the water of the World Ocean is 35 g/l, and at a salinity of 60 g/l, the main part of the cells cannot exist. The removal of salts by rivers into the ocean would double the concentration of salts every 80 million years, if not for the natural processes that remove salts from ocean water. Under these conditions, the relative stability of ocean salinity has been maintained for several hundred million years.[ ...]
biochemical properties. All biochemical decomposition processes organic matter Wastewater in the seas and oceans flow much more slowly than in freshwater basins. This is due to the fact that the concentration of salts in salt water is greater than in fresh water and therefore the osmotic pressure with which the microbial cell absorbs the nutrients necessary for its life decreases (Gaultier, 1954). Accordingly, the decrease in the value of BODz in sea water in the process of its self-purification occurs much more slowly than in fresh water.[ ...]
The temperate and tropical land belts, with their humid climate and developed biostrome, continue on the ocean as belts of high biological productivity. Subtropical desert belts of land with a poorly developed biostrome can be equally traced over the ocean. Ultimately, the lack of moisture both on land and in the ocean leads to a similar result for the bios - deserts appear, almost devoid of life”2.[ ...]
A small amount of work, of course, could not contain the huge information that is associated with the problem of water desalination. But we tried to show that the idea of obtaining fresh water from colossal salty waters of the seas and oceans occupied the minds of ancient thinkers and has now acquired real forms of not only technological, but also technical solutions. Today, entire cities have grown on the sun-scorched, waterless land thanks to the found ways to desalinate sea water on an industrial scale.[ ...]
Regarding this project, M. Ewing's forecast about the consequences of the implementation of the dam construction is known. According to this forecast, the cessation of the flow of more saline waters into the Atlantic Ocean may, within three decades, lead to such a decrease in salinity in it that it will entail a complete change in the circulation of ocean waters, which may ultimately result in the cessation of the flow of warm Gulf Stream waters into the Arctic and cooling there with simultaneous warming in continental Europe. At one time, this forecast evoked a negative reaction from another well-known oceanologist, G. Stommel, who pointed out that on the basis of M. Ewing's assumptions, reverse processes could be predicted with the same success. This example is given in order to show the complexity and ambiguity of such forecasts in the current state of ocean science, even for stationary processes of water mass exchange.[ ...]
Various water masses are separated by frontal zones or frontal surfaces, in which the gradients of water mass characteristics become sharper. Quasi-stationary climatic frontal zones are the natural boundaries of the main water masses in the ocean. Five types of fronts are distinguished in the open ocean: equatorial, subequatorial, tropical, subpolar, and polar. The frontal zones are distinguished by the high dynamism of the processes occurring in them. In the coastal zone, in the estuarine zone, fronts are formed that separate the shelf or runoff waters from the waters of the deep part. The formation of one or another type of front depends on external conditions. According to the data of subsurface towing of temperature and salinity probes (measurements were carried out at a depth of 30 cm), with a front width of about 70 m, the salinity and temperature gradients are 2.2%o and 1.1° per 10 m, respectively. flow of fresh river water over saline and dense sea water. In the case of the inflow of Baltic waters into the lagoon, an intrusion front of heavy sea waters into the lighter waters of the lagoon is formed. When a wedge of saline sea waters propagates along a deep sea channel, a typical estuarine front is observed. A typical change in temperature, salinity and density at the front crossing is shown in fig. 6.5.[...]
This type of renewable energy resources is perhaps the most exotic, and the youngest in development time: the first technical ideas date back only to the 70s. our century. The renewal of this type of resource is associated with the transformation of part of the thermal energy of the ocean during the evaporation of water from its surface. This, as already noted, consumes about 54% of the total balance of energy coming from the Sun. When fresh water enters in the form of precipitation and river runoff back into the ocean, in the process of mixing with salt water, energy is released that is practically proportional to the magnitude of the change in the entropy of the fresh-ocean water system, which is a measure of the orderliness of this system. The change in entropy itself is an unobservable phenomenon, therefore, for example, in the mouths of rivers there are no noticeable manifestations of the release of additional energy. The energy of dissolution can be determined by first finding the value of the equilibrium osmotic pressure that occurs on a thin film that separates fresh and ocean water and has the ability to pass only water molecules. The penetration of H2O molecules continues until the pressure of the solution column balances the osmotic pressure, as a result of which equilibrium conditions are established between the solution and the solvent.[ ...]
At present, work on the organization of irrigated agriculture for growing perennial grasses and vegetables in the steppe zone continues, but small irrigated fields with an area of tens (not more than 200-300) hectares are being created, water intake is carried out from artificial reservoirs where spring snow water accumulates. Watering from lakes is prohibited, where interference with the hydrological regime is especially dangerous, as it can lead to irreversible changes in their ecosystems (for example, to the disappearance of fish and blooming of water, i.e., the massive development of cyanobacteria, etc.). HYDROSPHERE (G.) - the water shell of the Earth, including oceans, seas, rivers, lakes, groundwater, glaciers. The structure of the G. of the Earth is shown in Table. 16. G. is 94% represented by the salty waters of the oceans and seas, and the contribution of rivers to the planet's water budget is 10 times less than the amount of water vapor in the atmosphere.[ ...]
Only the uppermost layers, 100–200 m thick, can be called true pelagic: in some places, foraminifera and pteropods make up more than 50% of them, while siliceous microfossils are rare. The increased salinity of the waters of the Red Sea probably prevents the development of radiolarians, and the appearance of these microorganisms in the section of Quaternary deposits corresponds to interglacial periods of high sea level, when the limitation of water exchange with the ocean was minimal. Coccolithophorites can withstand harsher conditions, but during the maximum of the last glaciation, salinity was so high that even the most tolerant forms eventually disappeared.