Lesson of the surrounding world fresh waters land. water sushi

It contains 1.3 billion km 3 of water, but a significant part of it is chemically bound to minerals. Groundwater is characterized by different chemical composition. According to the degree of mineralization, they can be either fresh or brines containing more than 35 g/l of salts.

Fresh water hydrosphere- source of life Earth. Water is found in rivers, lakes, reservoirs, springs, springs, underground springs, and glaciers.

Most fresh water is stored in glaciers. The most powerful glaciers are in Antarctica. The ice thickness there reaches 4 km.

Water found in the pores, voids and cracks of rocks in the upper part of the earth's crust. Groundwater is formed mainly due to the seepage of rain and melt water deep into the earth. Water easily seeps through layers of sand, gravel, and pebbles. The strata consisting of these rocks are called permeable. Rock layers that do not allow water to pass through are called waterproof; they consist of clay, granite, sandstone, and shale. Since the upper part of the earth's crust has a layered structure and the layers can consist of both water-resistant and water-permeable rocks, groundwater occurs in layers. Layers of permeable rocks containing water are called aquifers.

Groundwater located in the aquifer lying on the first aquifer layer is called groundwater. And groundwater confined between two impermeable layers is interstratal.

If the aquifer is located between two water-resistant layers and these layers are bent in the form of a bowl (Fig. 18), then the water in the lower part of the bend of the layers will be under pressure. Water begins to gush from a well drilled in this place to the aquifer. Such groundwater outlets are called artesian wells.

The groundwater surface is called groundwater level. The height of the groundwater level depends on many factors: 1) the amount of precipitation; 2) the dissection of the area, i.e., the number and depth of ravines and rivers in a given area; 3) from the proximity and fullness of rivers and lakes.

If the waterproof layer has a slope in one direction or another, then water begins to flow along it in the direction of the slope and usually somewhere, more often in a valley, ravine, at the foot of the slope, it comes to the surface. The place where groundwater comes to the surface is called a source, spring or spring. In some areas of the globe, water comes to the surface of the earth, in which salts and gases are dissolved. This type of water is called mineral water.

If groundwater is replenished annually and its quantity remains unchanged, then interstratal waters are replenished very slowly, since their accumulation took hundreds and even thousands of years.

Rivers form the most important part hydrosphere.

The source of the river, i.e. the place where it begins can be a spring gushing out from under the ground, a swamp, a lake. In high mountains, rivers usually start from glaciers.

If you swim with the flow of the river, then on the right there will be the right bank, and on the left - the left.

The place where a river flows into another river, lake or sea is called mouth. Every river flows in a depression that stretches from the source of the river to its mouth - river valley. A depression in a river valley through which river waters constantly flow is called river bed.

During a flood, most often in the spring, when the snow melts, the river overflows its banks and floods the lower part of the river valley - I'll understand.

A river with all its tributaries, including rivers flowing into tributaries, forms a river system. The area from which a river and its tributaries collect water is called the river's drainage basin. The largest area of ​​the Amazon River basin in South America is over 7 million km2. Each river has its own basin. The boundary between river basins is called a watershed.

Territories of the mainland that do not have drainage ocean are called pools internal drain. These include, for example, a significant part of the East European Plain in Eurasia, along which the Volga River flows.

The area from which water flows into a particular ocean is called basin of this ocean.

Let's look at examples. The rivers of Africa belong to the basins of the Atlantic (Nile, Congo, Niger) and Indian (Zambezi, Limpopo) oceans. Stretching along the west coast of South America mountains The Andes serve as a watershed between the Atlantic and Pacific oceans. All major rivers of South America carry their waters to the Atlantic Ocean. This is the most abundant river in the world - the Amazon, as well as the Parana and Orinoco.

School: No. 36 Teacher: Volkova L.V.

Class: 2-a

Lesson topic: Fresh waters of land. Rivers and people.

Lesson objectives: familiarize with the features of rivers (source, mouth, banks, etc.), the reasons for river flow, their full flow, teach how to find the most important rivers on a map and show them correctly, familiarize with the features of lakes, teach how to find the most important lakes on a map and show them correctly show.

Planned results:

Personal: expressed stable educational and cognitive motivation for learning; the formation of a sustainable educational and cognitive interest in new ways of solving problems, the desire to continue studying;

Metasubject: Learn to plan educational activities at the lesson; express your version, try to suggest a way to check it (based on productive tasks in the textbook); working according to the proposed plan, use the necessary means (textbook, simple devices and tools).

Subject: Students will learn to discuss issues, argue, and draw conclusions.

Equipment: textbook " The world» O.T. Poglazova part 2, notebooks for independent work, presentation;

Slide captions:

Fresh water sushi. River and people.

Not a horse, but a forest running, not a noise

A river is a natural stream of water that constantly flows in a depression it has developed - a channel. What is a river?

And what parts does the river consist of? Source – beginning of the river RODNIK GLACIER SWAMP LAKE CONFLICT OF RIVERS

SOURCE - the place where the river begins

TRIBUTOR - a small river flowing into a large river

Estuary – a place where a river flows into the sea, lake, or another river

Flow of the river Source - the beginning of the river Mouth - the place where the river flows into the ocean, sea, lake, river Main river Right tributary Left tributary Length of the river Parts of the river

WHY DOESN'T THE RIVER END OF WATER?

flat What types of rivers are there? mountain

about appreciating your work in the lesson 1. I worked in the lesson 2. I worked in the lesson 3. The lesson seemed to me 4. For the lesson I 5. My mood 6. I was actively / passively satisfied / not satisfied with the lesson material short / long not tired / tired got better / got worse understandable / not clear useful / useless interesting / boring easy / difficult interesting / uninteresting

Fresh water hydrosphere- the source of life on Earth. It is found in rivers, lakes, reservoirs, springs, springs, groundwater, and glaciers.

Most fresh water is stored in glaciers. The most powerful glaciers are in Antarctica. The ice thickness there reaches 4 km.
The groundwater- water located in the pores, voids and cracks of rocks in the upper part of the earth's crust. Groundwater is formed mainly due to the seepage of rain and melt water deep into the earth. Water easily seeps through layers of sand, gravel, and pebbles. The strata consisting of these rocks are called permeable.
Rock layers that do not allow water to pass through are called waterproof. Aquifers consist of clay, granite, sandstone, and shale. Since the upper part of the earth's crust has a layered structure and the layers can consist of both waterproof and waterproof rocks, groundwater occurs in layers. Layers of permeable rocks containing water are called aquifers.
Groundwater located in the aquifer lying on the first aquifer layer is called groundwater. And groundwater contained between two impermeable layers is interstratal.
If the aquifer is between two aquifers and they are bent in the shape of a bowl, then the water at the bottom of the bend of the strata will be under pressure. From a well drilled in this place, water from the aquifer begins to gush out. Such outlets of underground water are called artesian wells.
The groundwater surface is called the water table. The groundwater level depends on many reasons: 1) the amount of precipitation; 2) the dissection of the area (i.e., the number and depth of ravines and rivers in a given area); 3) from the proximity and fullness of rivers and lakes, etc.
If the aquifer has a slope in one direction or another, then the water begins to flow in the direction of the slope and usually comes to the surface somewhere in a valley, in a ravine or at the foot of the slope. The place where groundwater comes to the surface is called a source, spring or spring.
In some areas of the globe, water comes to the surface of the earth, in which salts and gases are dissolved. This type of water is called mineral water.
If groundwater is replenished annually and its quantity remains unchanged, then interstratal waters are replenished very slowly, since their accumulation takes hundreds and even thousands of years.
Rivers. These are natural water streams flowing in the channel they have developed. If you swim with the flow of the river, then on the right there will be the right bank, and on the left - the left. The source of a river, that is, the place where it begins, can be a spring gushing out from under the ground, or a swamp, or a lake. In high mountains, rivers usually start from glaciers.
The place where a river flows into another river, lake or sea is called an estuary. Every river flows in a depression that stretches from the source of the river to its mouth - this is a river valley. The depression in a river valley through which the waters of the river constantly flow is called the river bed.
During a flood, most often in the spring, when the snow melts, the river overflows its banks and floods the lower part of the river valley - the floodplain.
A river with all its tributaries, including rivers flowing into tributaries, forms a river system.
The area from which a river and its tributaries collect water is called the river's drainage basin.
Each river has its own basin. The boundary between river basins is called a watershed.
The terrain affects the direction and nature of the river's flow. Mountain rivers, as a rule, have a rapid, turbulent current. They flow in narrow rocky valleys with steep slopes. Lowland rivers have a calm current; they flow in a wide valley with a fertile floodplain.
Thresholds. The bottom of river valleys in lowland rivers is composed mainly of soft rocks, which are relatively easily washed away by the current. But in some places there are hard rocks: limestones, granites, shales. They are eroded by water flow more slowly. When they block the channel, rapids form on the river. The most common rapids are on mountain rivers.

If a river encounters a steep ledge on its way, then the water falling from it forms a waterfall. The world's highest waterfall, Angel Falls, is located on the Churun ​​River (Orinoco River system in South America). Its height is 1054 m. The most powerful are Victoria Falls on the Zambezi River in Africa and Niagara Falls on the Niagara River in North America.
High water- an annual increase in water in a river and a strong rise in its level during a certain season of the year. The Volga, for example, floods in the spring when the snow melts, but the Amur floods in the summer, during the monsoon rains. In summer, mountain rivers also overflow due to the rapid melting of glaciers.
A flood should be distinguished from a flood. Flood is a sudden rise in the water level in a river caused by heavy rainfall, enhanced by the melting of snow or glaciers.
There are rivers that are full throughout the year. These include rivers of the humid tropical zone (Congo, Amazon). These river basins receive heavy rainfall all year round.
When a river flows into the sea, sand, clay, and gravel brought by the river are deposited at the bottom, forming a delta. The largest delta in our country is the Lena River. Large deltas are also near the Nile, Volga, and Mississippi rivers.
Economic use of rivers. In many areas of the world, rivers are the main source of electricity. Fresh water is used by humans for domestic, agricultural and industrial needs. Rivers are also important as routes of communication.
Lakes. A lake is any large closed natural depression on the surface of the Earth filled with water. The largest lake on Earth is the Caspian, it is also called the sea. It is called a lake because it is not connected to the World Ocean. Russia is home to the deepest lake on the globe - Baikal.
Based on the method of formation, lake basins can be divided into several types. Let's name some of them. Dammed, or dammed, lakes were formed by damming or partially blocking the river bed as a result of a collapse or shedding of rocks into the river valley. An example of a dammed lake is Lake Sarez in the Pamirs.
Residual lakes are the remains of the sea (Caspian, Aral). There are lakes whose basins were formed as a result of mountain-building processes. For example, Lake Baikal is located in the basin. There are volcanic, or crater, lakes. Their lake basins are located in the craters of extinct volcanoes. There are many such lakes on the island of Java, the Kuril Islands, and Kamchatka. In the floodplains of rivers there are often small lakes, which are the remains of former river channels. They are called oxbow lakes. There are also basins of glacial origin and artificial ones (reservoirs).
If a river flows out of a lake, then such a lake is called a waste lake. In dry areas there are lakes from which rivers do not flow. They are called drainless. In such lakes the water is usually salty. Why? Everything is explained simply. The water in each river contains a small amount of salt. The river flows into a closed lake, the water from its surface evaporates, and the salt remains in the lake. In a hot and dry climate with high evaporation and limited water flow into the lake, its salinity will constantly increase. Excess salts will begin to settle at the bottom until it fills the entire lake basin. This is how a salt marsh is formed.
Sometimes swamps form in place of lakes. Sand and clay settle at the bottom of lake basins, causing the lakes to become shallow. Reeds and reeds grow on the shallows. When the plants die, they settle on the bottom of the lake, and after some time peat is formed from them.
Reservoirs created by building a dam across a river valley. Sections of rivers such as the Volga, Kama, and Dnieper have been turned into cascades of reservoirs. Powerful hydroelectric power stations were built on them. However, the construction of reservoirs also has negative aspects: fertile lands are flooded, the groundwater level around the reservoir rises, which leads to swamping of the area.
It should be remembered that all the constituent components of nature - relief, atmospheric air, land waters, rocks, soil, plants and animals - are interconnected, and if one of them changes, then sooner or later the others will change.

Land surface waters include lakes, rivers, swamps and glaciers.

Lakes

Lakes are important objects of the hydrosphere because they are reservoirs of fresh water. A lake is a depression on the land surface that is constantly filled with water.. Lakes are fed by atmospheric precipitation, surface water flowing into them along the slopes, streams and rivers flowing into them, and groundwater outlets at the bottom. Distinguish sewage lakes from which river(s) flow, and drainless, in which water is consumed only by evaporation. The depression in which the reservoir is located is called lake basin. Depending on the causes (origin) of lake basins, the following lakes are distinguished: tectonic, volcanic, dam (dammed), floodplain, glacial, karst, thermokarst and artificial (reservoirs).

Tectonic lake basins are formed as a result of tectonic movements, leading to the subsidence of sections of the earth's crust and to the subsidence of blocks of the earth's crust along faults with the formation of grabens. These are the largest and deepest lakes - the Caspian Sea-lake, the Aral Sea-lake, Baikal, Tanganyika. Volcanic lakes are lakes formed in the craters of dormant or extinct volcanoes. Zavalnye lakes are formed in the mountains as a result of the collapse of large masses of rocks, blocking the valley of a mountain river in the form of a dam, for example, Lake Sarez in the Pamirs. Floodplain lakes arise in river valleys as a result of the separation of bends (meanders) from the riverbed, which turn into closed elongated reservoirs of a curved shape - oxbow lakes.

Glacial lakes are lakes whose basins were formed as a result of the plowing or accumulative activity of glaciers. They are widely developed in areas that were subject to glaciation in the past. In areas where the removal of material (denudation) predominated, mainly lacustrine hollows of plowing were developed (lakes in Finland, Karelia, the Kola Peninsula), and in areas where moraine deposits accumulated in the form of hills and ridges, they formed in closed interhill areas. in depressions there are numerous lake basins of glacial accumulation (for example, lakes of the Valdai Upland or lakes of the southern part of the Karelian Isthmus).

Karst lakes form in areas where soluble carbonate rocks (limestone) develop. Among them are karst land lakes, the basins of which were formed on the earth's surface as a result of the collapse of underground cavities, and karst underground lakes in karst caves. Thermokarst lakes arise in areas of permafrost distribution due to the non-simultaneous thawing of the upper boundary of permafrost for various reasons (mechanical composition of soils, vegetation, etc.). As a result of thawing, saucer-shaped depressions are formed in the relief, which are filled with melt water.

Artificial lakes are created by humans most often as a result of damming river valleys in order to generate electricity or to create the necessary water reserves for industrial, agricultural and domestic needs. Such lakes are called reservoirs. Artificial lakes are also formed as a result of filling waste quarries with water.

In the distribution of lakes on Earth, climatic zonality is observed, associated with the humidification of the territory, depending on the amount of precipitation and the amount of evaporation. The largest number of lakes is observed in the tundra zone, fewer in the forest zone, and very few in the steppe zone. The distribution on the earth's surface is also related to the amount of moisture. fresh And salt lakes. Let us remind you that water is considered fresh if it contains no more than 1 g/liter of salts dissolved, brackish water – up to 25 g/liter, salty – from 25 to 37 g/liter and mineralized – more than 37 g/liter. The waters entering the lake always contain some amount of dissolved salts. In the absence of a constant influx of fresh water (rivers) in the lake, as a result of intense evaporation, a gradual increase in the salinity of the lake water occurs. Therefore, salt lakes are usually confined to areas with a hot and dry summer climate and, as a rule, are drainless. The occurrence of salt-containing rocks within the drainage area also contributes to the appearance of salt lakes. Depending on which salts, soda, sulfate or chloride lakes are more distinguished. In highly mineralized lakes, self-precipitation of salts occurs, as, for example, in lakes Elton and Baskunchak.

Questions for self-control.

1. What is land surface water?
2. What is a lake?
3. What types of lakes are there depending on the flow?
4. What is a lake basin?
5. What groups are lakes divided into depending on the origin of the basins?
6. How and why does zonality manifest itself in the distribution of the number of lakes on Earth?
7. What water is considered fresh, brackish, salty, mineralized?
8. What types of salt lakes are there depending on the composition of the salts?

Rivers

Rivers play a major role in the water cycle, returning water to the World Ocean. The annual volume of water returned by all rivers on Earth is approximately 40,000 km 3 . A river is a constant water stream flowing in a channel it has developed, fed by surface and groundwater. The place where the river originates is called source river, and the place where it flows into a body of water (sea, lake, ocean) or into another river is mouth. Highlight home a river flowing directly into a body of water, and tributaries flowing into other rivers. The main river and its tributaries form river system. The earth's surface, together with the underlying soils, from which a river system collects its waters, is called river drainage basin or simply catchment area. The catchments of two neighboring rivers are separated by a watershed. Watershed- this is a line dividing slopes directed in different directions along which atmospheric water flows. Highlight: World watershed, which separates river flow entering different oceans; main watershed, separating the basins of the main rivers; lateral divide, separating the basins of adjacent tributaries of the main river. Rivers are divided into lowland And mountain.

Rivers exist due to the flow of water into them from various food sources. There are 4 types of food: rain, snowy, glacial And underground. Most often observed mixed nutrition. Depending on the location of the river and the season, one or another type of nutrition predominates. The equatorial, tropical and subtropical zones are characterized by rain nutrition, while the temperate zone with cold, snowy winters is characterized by snow nutrition. Rivers originating in high glaciated mountains are fed by glaciers. Groundwater feeds rivers in winter and during the absence of rainfall, so they do not dry out either in summer or winter.

The main characteristics of a river are flow speed, water level and flow. Current speed rivers depends on the fall and slope of the river. A fall river is the difference in height between the source and the mouth of the river. Slope river is the ratio of the difference in heights of the extreme points of a river section (or the entire river) to its (its) length, usually represented in %. The speed of river flow varies widely from several centimeters per second in lowland rivers to several meters per second in mountain rivers. The speed of water flow affects the rate of renewal of water in the river. Rivers have a high rate of water exchange. On average, all the water in all the rivers of the world is renewed every 11 days.

Water level in the river is not a constant value. The change in level depends on the volume of water entering the river and is seasonal. The highest water levels are observed during intense snowmelt in the spring and after prolonged or heavy rains. High level water associated with spring snowmelt is called flood, and the rise in water level in the river caused by rainfall - flood. Most low level the water in the river is called low water. During low water periods, the river is fed mainly by groundwater. Distinguish summer And winter low water.

Water level is closely related to water flow. Water consumption is the volume of water in m3 passing through the cross section of the channel in 1 second. Most high consumption water has a river Amazon. An average of 220,000 m3 of water per second flows through its cross-section at the mouth. In Russia, the highest flow rate is observed near the Yenisei - 19,800 m 3 /s. The flow of water in a river over large periods of time (month, season, year) is called drain. Fluctuations in the level and flow of water in a river characterize it water regime. The water regime directly depends on the climate. For example, rivers such as the Amazon and Congo, located in the humid tropical zone, are full of water all year round due to the constant heavy rainfall there. Rivers flowing in areas with a monsoon climate flood only in summer, during the monsoon rains. Temperate rivers freeze in the winter and flood in the spring when the snow melts. High water, freshet, summer and winter low water, freeze-up are phases of the water regime.

Questions for self-control.

1. What is a river?

1. What is stock?
2. What is the annual flow of rivers on Earth?
3. What is a river system, watershed, watershed?
4. What types of watersheds are there?
5. What types of river nutrition exist?
6. What are the main characteristics of the river?
7. What is called high water, high water, low water?
8. What is water consumption?
9. What is water regime?
10. What are the phases of the water regime?

Swamps

Swamps are also important hydrosphere objects because they store moisture and contain large amounts of it. It is in the swamps that the sources of many, including large rivers, are located. For example, the largest river in Europe, the Volga, originates from a swamp on the Valdai Hills. The water reserves contained in all the Earth's swamps are estimated at 11.5 thousand km 3. A swamp is a constantly waterlogged area of ​​the earth's surface with moisture-loving vegetation, as a result of the death of which peat is formed. Swamps arise as a result of overgrowing lakes or excessive moisture of the earth's surface. When lakes become overgrown, they first gradually become shallow due to the deposition of wind-blown dust and clay particles, as well as microscopic animals and algae, often in large quantities. Then, aquatic plants (water lilies, reeds, reeds) settle in the shallowed reservoir, which, dying, settle at the bottom, thereby increasing the rate of shallowing of the reservoir. As a result, the reservoir turns into a swamp, and open areas of water (“windows”) remain from the former lake in its deepest places.

Excessive moistening of the earth's surface occurs either due to the proximity to the surface of groundwater, or as a result of the excess of precipitation over the amount of evaporation. In both cases, swamping of the territory occurs, which consists of increased soil moisture, making it difficult for air (oxygen) to enter it, and the settlement of moisture-loving vegetation (ledum, various mosses, etc.). Mosses enhance the accumulation of moisture due to their high moisture capacity and reduce evaporation, thereby contributing to even greater waterlogging of the area. Swamps are widespread in forest and tundra zones.

Depending on the feeding regime, lowland, highland and transitional swamps are distinguished. Lowland swamps are located in depressions (for example, in river valleys) and are fed by groundwater that comes to the surface at the foot of the slopes or lies close to the surface. They have a concave, flat or slightly inclined surface. The vegetation of lowland swamps is quite diverse and is represented in the temperate zone by woody (alder, birch, willow) and herbaceous (sedge, reed, etc.) species. Grass swamps are widely developed on floodplains and in deltas of large rivers.

Horse swamps are most often located on flat watersheds and are fed by atmospheric precipitation, which has weak mineralization. They are also formed if the lake is completely overgrown. Due to poor mineral nutrition, a monotonous vegetation is formed, represented by a carpet of sphagnum mosses and frequently occurring cotton grass, heather, dwarf birch, cranberries, etc. Along the edges of the swamps, depending on the region, oppressed forms of pine or larch are found. Raised bogs have a convex surface as a result of the rapid growth of sphagnum mosses in the center of the bog, where mineral nutrition is minimal (sphagnum mosses have little demand for mineral nutrition).

Swamps transitional type, in terms of the nature of nutrition and vegetation, occupy an intermediate position between lowland and highland swamps. In low areas, where there is a connection with groundwater, the vegetation of lowland swamps is developed, and in elevated areas (hummocks, elevations near trunks and stumps) the vegetation of raised swamps is developed.

Questions for self-control.

1. What is a swamp?
2. What types of swamps exist depending on their diet?
3. What is characteristic of lowland swamps?
4. What is characteristic of raised bogs?

5. What is characteristic of transitional type swamps?

Glaciers

Glaciers cover about 11% of the land surface. They contain approximately 30 million km 3 of clean fresh water. Glacier is a mass of ice moving along the earth's surface, formed as a result of the accumulation and recrystallization of solid atmospheric precipitation (snow). The largest cover glaciers are located in Antarctica and Greenland, the largest ones are on the islands of Iceland, Spitsbergen, Novaya Zemlya and Severnaya Zemlya. Snow accumulation can only occur above a conventional boundary, which is called snow line (border). Above it, snow accumulation prevails over its melting and evaporation. The snow line at the poles drops to sea level, and at the equator it is located at an altitude of about 5 km. In the Caucasus it is located at an altitude of about 3.5 km. The location of the snow line depends on climatic conditions and is subject to cyclicity. Therefore, glaciers can advance and retreat, appear and disappear. During the Quaternary period, due to global cooling and warming, there were repeated changes in the height of the snow line, which led to the appearance and disappearance of cover glaciers over large areas of the Earth.

Snow accumulating in depressions (depressions) or on a flat surface, under the influence of solar heat, thaws and compaction, undergoes recrystallization, turning first into firn, and then as a result of the pressure of the overlying layers into ice. Ice exhibits fluidity under constant pressure. Ice flow in glaciers occurs under the influence of its own weight and gravity. Thus, in the glacier there are accumulation area(feed) where ice volume increases, and area of ​​expenditure(decrease, runoff), where due to melting, evaporation or breaking off of ice, its mass decreases. For mountain glaciers, the accumulation area is located above the snow line, below it it descends along the valley glacier tongue, related to the area of ​​ice consumption.

Ice sheets form at high latitudes, where the snow line descends to the earth's surface and the accumulation of solid precipitation exceeds its melting and evaporation. The center of a glacier forms where snow accumulation is greatest, so its central part is the accumulation area. The cover glacier has a convex shape in the form of a shield, due to the slow spreading of ice from the center to the edges. Its peripheral part represents the expenditure area. The largest sheet glacier is located in Antarctica. Its thickness averages about 2 km, with a maximum thickness of up to 4 km. The formation of this powerful cover glacier began in the Neogene period, 12 million years ago, during a general climatic cooling on Earth. Its edges descend into the sea, forming ice shelves, some of which lie on the bottom, and the other is in a floating state. When the ends of ice shelves break off, they form icebergs. The largest icebergs reach a length of a few kilometers and a height of up to 100 m. The largest part of the iceberg (up to 90% of its volume) is under water. Icebergs are carried by sea currents and winds to lower latitudes, where they gradually melt. Antarctic icebergs reach 45°S, and Greenland icebergs reach 40°N, and in rare cases they are observed at even lower latitudes.

Questions for self-control.

1. What is a glacier?
2. What proportion of the land surface is occupied by glaciers?
3. How much fresh water is contained in the Earth's glaciers?
4. What types of glaciers are there?
5. What is a snow line?
6. At what altitude is the snow line at the poles, at the equator, in the Caucasus?
7. What is a mountain glacier?
8. What is a sheet glacier?
9. What is the maximum ice thickness of the ice cap in Antarctica?
10. What is an ice shelf?
11. How are icebergs formed?

10. BIOSPHERE

All organisms (plants, animals, microorganisms (bacteria, viruses, etc.), fungi) living on Earth constitute a special living shell (film of life). This shell was first called the “biosphere” in 1875 by the Austrian geologist E. Suess. In this narrow sense, the biosphere is the totality of organisms existing on Earth. During the entire evolution of organisms (more than 3.5 billion years), about 500 million species of animals and plants existed on Earth. Today on Earth there are about 1.8 million species of animals and 0.5 million species of plants, and the biodiversity of fungi and microorganisms is impossible to calculate; according to some estimates, it ranges from 3 million species or more.

Organisms are distributed extremely unevenly in the biosphere. The total mass of living matter per unit surface or volume of water, land or air is called biomass Earth. On land, biomass decreases in 3 directions from equatorial latitudes, where it is maximum - towards tropical deserts, where there is a lack of water; then towards the polar latitudes and, finally, towards the highlands, where there is a lack of heat. Land biomass far exceeds ocean biomass due to the predominance of plant biomass. The ocean is dominated by animal biomass, most of which is plankton. In warm equatorial and tropical latitudes there is a huge diversity of species of organisms, but the number of individuals of each species is limited. In cold latitudes, on the contrary, species diversity is limited, but the number of individuals of each species is large.

The spread of life on Earth was helped by the ability of organisms to adapt to a wide variety of environmental conditions. Some organisms are adapted to life on ice and on the bottom of deep ocean basins. Organisms can live even in an aggressive environment: microorganisms were found on the ocean floor in hot thermal springs with temperatures of about 300 o C, in the casing of a nuclear reactor, in the water of geysers, anaerobic bacteria (capable of living without oxygen) were found at great depths in the earth's crust. Therefore, it is not surprising that life spread very quickly on Earth.

The maximum concentration of organisms is located at the border of contrasting environments: on the land surface, in the surface layer of the ocean, in the bottom layer of the ocean, at the boundaries of warm and cold currents, in the coastal strip of land. All of these are contact zones between the lithosphere, hydrosphere and atmosphere.

The peculiarity of living organisms is the constant exchange of matter and energy with environment in the form of a biological cycle in nature. The essence of the cycle comes down to two opposite processes - the creation of organic matter due to solar energy during the process of photosynthesis of plants and its further destruction with the help of microorganisms into simple mineral substances, which are then again absorbed by plants.

Organisms are actively involved in the general cycle of substances, changing the main nature-forming components. Almost all the oxygen in the atmosphere, and therefore the ozone layer, which saves all life on earth from the destructive ultraviolet solar radiation, is created thanks to the vital activity of organisms. Organisms removed a huge amount of carbon dioxide from the atmosphere and transferred it to sedimentary rocks (chalk, limestone-shell rock, reef limestones, coal, oil shale). As a result, the gas composition of the atmosphere changed and took on its current state. In addition, during their existence, organisms absorbed and stored in the form of fossil fuels a huge amount of solar energy. An example of such “conservation” could be peat, coal, oil and gas. They processed large masses of matter, creating the planet's soil cover.

It is estimated that oxygen in the atmosphere completes its circulation through organisms in approximately 2 thousand years, and carbon dioxide in 6.3 years. All water on Earth decomposes and is restored by living organisms within 2 million years. In addition, it is known that organisms absorb almost all chemical elements. It can be stated that the atoms of almost all of them have passed through living matter many times. chemical elements. As a result, the cycle of substances on Earth began to be of a biotic nature.

Thus, over the long period of their existence, organisms had a huge impact on the further evolution of geospheres, in which qualitative changes occurred:

The photosynthesis process started and a change in the gas composition of the atmosphere occurred (the amount of CO 2 decreased and the O 2 content increased), thus, the reducing environment was replaced by an oxidizing one;

The chemical and gas composition of the waters of the World Ocean is formed largely due to the influence of the biochemical activity of organisms;

A new type of sedimentary rock of organic origin (limestone, peat, coal, oil) appeared in the lithosphere and processes of organic weathering began. organisms play a very important role in the processes of soil formation and the formation of certain forms of relief - for example, coral islands.

Organisms not only changed the cycle of substances on a global scale, but also began to play a decisive geochemical role in the overall cycle of substances. This is exactly what the great Russian scientist V.I. established at the beginning of the 20th century. Vernadsky. He considered organisms taken as a whole the most powerful force in its final results on the earth's surface. He called the state of the Earth, in which organisms play a major role in the general cycle of substances, the biosphere. In this case, by biosphere he meant the sphere of activity of living organisms, the area of ​​interaction between living and nonliving (inert) matter, which includes the lower part of the atmosphere, the entire hydrosphere, the upper part of the lithosphere and all organisms living on Earth. That is The biosphere in a broad sense is the shell of the Earth, where the interaction of living and nonliving (inert) matter occurs, as a result of which the activity of organisms acquires global significance.

IN AND. Vernadsky, creating in the 20-30s. 20th century the doctrine of the biosphere, also determined the theoretical boundaries of the biosphere - from the ozone layer in the atmosphere at an average altitude of 20 km to a depth of 10 - 12 km in the lithosphere, where, according to calculations, the isotherm of 100 ºС is located. Consequently, the thickness (thickness) of the biosphere is about 30 kilometers. In practice, the power of the biosphere is even less. Expeditions to Everest have shown that at altitudes above 7 km there are no reproductive organisms. In the lithosphere, organisms appear to be distributed to the depth of groundwater.

Thus, there are two definitions of the biosphere: narrow and broad. On the one hand, this is only the totality of organisms living on Earth (the film of life according to V.I. Vernadsky), and on the other hand, according to V.I. Vernadsky is the sphere of active interaction of shells. According to the authors, this double meaning of the term “biosphere” confuses students and makes it difficult for them to perceive the material. Attempts to replace one of the terms were made several times, but they were not widely used. The authors propose to base the new term on the concept of “biota”. Biota is a collection of organisms living in a large limited area and not necessarily interconnected by food (trophic) chains. For example, the biota of Western Siberia, the biota of the Far East, etc. Planet Earth also has a limited area and it is completely legitimate to name the entire set of organisms living on Earth, biotosphere. In this case, a dual interpretation of the concept “biosphere” is excluded.

Currently, the biosphere is experiencing strong anthropogenic impact economic activity humans, and the consequences of this impact are ambiguous:

On the one hand, man creates new species of plants and breeds of animals; it accelerates the evolution of species in nature; enriches natural communities by acclimatizing living organisms; increases soil fertility; creates reserves, protected natural areas,

On the other hand, there is intensive destruction of natural vegetation and rare animals; living conditions for living organisms (including humans) are deteriorating; Soil destruction occurs as a result of erosion and deflation processes.

Therefore, one of the most important problems of our time is the protection of the biosphere and the rational use of its resources.

Questions for self-control.

1. What is called the biosphere and what components are included in its composition?

2. Where are the boundaries of the biosphere?

3. What are the features of the distribution of living organisms on Earth?

4. How did the appearance of living organisms influence the further evolution of geospheres?

OK. 35.8 million km³ ). The waters of the land are mostly fresh.

Big Encyclopedic Dictionary. 2000 .

See what “WATER SUSHI” is in other dictionaries:

WATER SUSHI- water (mostly fresh), carried by rivers and concentrated in lakes, reservoirs, ponds, canals, swamps, contained in glaciers, as well as groundwater. According to rough estimates (Shchukin, 1980), water reserves in river beds around the globe... ... Ecological dictionary

water sushi- Water from rivers, lakes, reservoirs, swamps, glaciers, as well as groundwater... Dictionary of Geography

Water from rivers, lakes, reservoirs, swamps, glaciers, as well as groundwater (total volume about 35.8 million km3). Mostly fresh. * * * WATER LAND WATER LAND, water of rivers (see RIVERS), lakes (see LAKES), reservoirs (see RESERVOIR), swamps (see SWAMP (in... ... encyclopedic Dictionary

water sushi- sausumos vandenys statusas T sritis ekologija ir aplinkotyra apibrėžtis Vandenys, susitelkę upėse, ežeruose, tvenkiniuose, pelkėse, dirvožemyje, ore ir uolienose. atitikmenys: engl. continental waters; terrestrial waters vok. Festland gewässer, n …

water sushi Ekologijos terminų aiškinamasis žodynas

Water from rivers, lakes, reservoirs, swamps, glaciers, as well as groundwater (total volume approx. 35.8 million km3). In the main fresh... Natural science. encyclopedic Dictionary

R 52.24.661-2004: Risk assessment of anthropogenic impact of priority pollutants on land surface waters- Terminology R 52.24.661 2004: Risk assessment of anthropogenic impact of priority pollutants on land surface waters: 3.1 abiotic component: Abiotic environment, representing a set of inorganic conditions (factors)… …

surface waters land- 3.12 land surface waters; PWS: Waters located on the land surface in the form of various water bodies (R 52.24.566). Source: R 52.24.741 2010: Assessment of the toxicity of surface water... Dictionary-reference book of terms of normative and technical documentation

internal waters- vidaus vandenys statusas T sritis ekologija ir aplinkotyra apibrėžtis Vandenys (upės, ežerai, dirbtiniai vandens telkiniai, išskyrus pajūrio teritorinius vandenis), esantys valstybės teritorijoje. atitikmenys: engl. internal waters vok.… … Ekologijos terminų aiškinamasis žodynas

- (Lay on the oars) command given on boats. Sushi paddles. At this command, the rowers remove the oar blades from the water and align them parallel to the water, and the oars themselves are set perpendicular to the center plane of the boat. Samoilov K.I.... ...Marine Dictionary

Books

• , . In the series of volumes containing the results of research from the International Polar Year 2008-2009, this book occupies a special place. It presents the results of a study of the Earth’s cryosphere and...
• Polar cryosphere and land waters. The book contains the results, first of all, of field studies of the Earth’s cryosphere and natural processes occurring in the cryosphere of polar latitudes, conducted in the Arctic and...