Physiography continents and oceans
NORTH AMERICA: NORTH AMERICAN EAST
Geographical position. The Coastal Plains are a group of lowlands located on the Gulf Coast, along the lower Mississippi River, on the Florida Peninsula, and on the coast. Atlantic Ocean south of the Chesapeake Bay (see physical-geographical zoning map of North America with links to photographs of the nature of the region).
Low altitudes above sea level, flat terrain and subtropical climate are their most typical features, reflected in the nature of soils and vegetation.
Geological structure. The entire strip of lowlands was formed at the site of the subsidence of Paleozoic folded structures, to which the Appalachians and the Washita Mountains also belong. Surface subsidence and accumulation of sediments occurred from the beginning of the Cretaceous to the Neogene. In some areas of the coast, for example in Louisiana, the subsidence continues today, reaching significant values - on average about 11 cm per 100 years, and in some places more than 1 cm per year.
The strip of lowlands surrounding the coast of the Gulf of Mexico and the Atlantic Ocean is composed of strata of Cretaceous and Cenozoic sediments (clays, limestones, sandstones), lying horizontally or obliquely. The lower Mississippi lowland is a giant trough filled with alluvial deposits.
The coastal part of the Mexican Lowland and the shelf of the Gulf of Mexico is one of the largest oil and gas bearing areas of the continent. Within its boundaries, 4,600 oil and 3,900 gas fields have been explored, confined to the Meso-Cenozoic cover of the young Epihercynian platform, where hydrocarbons often accumulate in salt domes. Genetically, the Gulf of Mexico basin is associated with a vast depression, the interior of which is filled with sea water. The Florida Peninsula is known for its large phosphorite deposits. The width of the 250-kilometer phosphorite-bearing belt in the north of the peninsula ranges from 10 to 40 km.
Relief. The relief of the Coastal Plains is characterized by the presence of clearly defined steps that were formed during the successive uplift of the land. In the rear part, the processes of erosion and selective denudation created a series of cuestas, the largest of which (“black prairie”) is confined to the outcrops of Eocene limestones and stretches along the Mexican lowland for hundreds of kilometers. At the same time, the nature of the Atlantic coastline indicates recent subsidence.
The main feature of the east and south coasts of the United States is the presence of the world's largest system of barrier islands, or island bars. Such islands are 3-30 km from the land and often stretch for several tens of kilometers along the coast, although their width usually does not exceed 2-5 km. Over the past decades, there has been an intensive erosion of the barrier islands and their general shift towards land. Despite the significant dynamism of the barrier system, its islands are intensively developed by people, many of them are connected to the mainland by bridges and are used for urban development.
Of the 282 barrier islands (121 off the east coast, the rest off the south), approximately 70 are urbanized, containing large cities - Atlantic City, Virginia Beach, etc., the port of Galveston, and the world-famous resort of Miami Beach. The John F. Kennedy Space Center is located on the Merritt barrier island off the east coast of Florida at Cape Canaveral. About 80 islands are designated as local recreational areas or nature reserves. Fifteen of the largest barrier islands have been acquired by the federal government to establish nature reserves and national coastal refuges. The remaining 120 islands are privately owned and largely undeveloped.
South of New York, flooded river mouths, which became wide sea bays as the land subsided, penetrated into the interior of the mainland to the foot of the Piedmont Plateau and divided the coastal plain into peninsular areas with little connection with each other. Thanks to such features of the structure of the coastline, the largest cities in this area are at the same time large ocean ports. Examples include Philadelphia on the Delaware River 160 km from the ocean, Baltimore on the shores of the Chesapeake Bay, and Washington on the lower reaches of the Potomac River.
The Florida Peninsula is a gentle rise no more than 100 m high, the edges of which are flooded by the sea. The marginal parts of the peninsula have relatively recently been freed from under the water and are distinguished by an extremely flat topography. Karst processes are widely developed on the limestone surface of the peninsula. There are large karst depressions (valleys, wells, caves with highly branched underground galleries), underground lakes and rivers.
Useful fossils. Oil and other minerals are extracted here.
Climatic conditions. IN summer time Coastal plains are influenced by tropical air masses. Air from the Atlantic Ocean and the Gulf of Mexico penetrates the interior of the continent in the form of the summer southeast monsoon, bringing large amounts of moisture. IN winter time relatively colder and drier continental air of temperate latitudes dominates. Throughout the plains, precipitation exceeds 1000 mm, and in some areas (in the southeast) it even reaches 1500 mm. The humidity of the climate, the evenness of the topography and poor soil drainage contribute to the spread of swamps, which still occupy significant areas, both on the coasts and in the interior.
The abundance of moisture is combined with high annual temperatures. Summer temperatures on average exceed 25 °C. Heat and abundance of moisture make summer favorable for growing subtropical crops, but such conditions are difficult for human health. But winter, especially in Florida, is the most favorable time of year (Fig. 70).
Rice. 70. Annual variation of temperatures, precipitation and relative humidity in Florida
The average winter temperature varies from north to south of the Coastal Plains from 4 to 16 °C; in southern Florida the average January temperature is 20 °C. However, cold air masses often penetrate from the north, which causes short-term frosts and snowfalls. Even in southern Florida, temperatures drop to 0°C and snow falls. Despite this, Florida is considered the best winter resort in North America.
In the summer, due to the meridional movement of air masses and the passage of cyclonic depressions, strong hurricanes often sweep over the Coastal Plains, accompanied by downpours. They cause catastrophic floods and cause great harm to the population. In August 1992, Hurricane Andrew caused enormous damage to the west coast of the Florida Peninsula. In recent years, the frequency and severity of these natural phenomena have increased; Now hurricanes occur not only in the summer, but also in the transition seasons.
Vegetation. The highest and driest hilly sandy areas of the plains are covered with leached red and yellow earth soils; Previously, they were occupied by forests of subtropical pine species - whiplash (Pinus caribaea), torch (Pinus taeda) and others, as well as thickets of the dwarf American sabal palm, which is a relic of pre-glacial times. In some areas, especially in the eastern part of the Mexican lowlands and on the east coast of Florida, subtropical pine forests have survived to this day and are important source wood and raw materials for obtaining turpentine.
In wetter places, mixed monsoon forests of ash, poplar, and magnolia grow, with a large number of vines and epiphytes. Swamps, widespread in the lowlands, have specific vegetation. In flooded and swampy areas, trees with plank-shaped support roots grow. The most characteristic is the so-called swamp cypress - a tree from the Taxodiaceae family, with red-brown, rot-resistant wood and cone-shaped respiratory roots. Between the trees there are many reeds, sedges and other marsh grasses, which form impenetrable thickets in places, alternating with areas of vegetation-free water.
Animal world. The swamps are home to a rich fauna. There you can find alligators, turtles and giant frogs. Particularly large areas are occupied by swamps in the Mississippian lowlands and north of the Florida Peninsula, on the border of Virginia and North Carolina.
Population and environmental problems. In southern Florida there is a huge swamp called the Everglades, covered with thickets of swamp cypress, swamp pine (Pinus palustris), sedges and reeds, interrupted by areas clean water. In 1947, a national park was created here on an area of more than 550 thousand hectares, which was subsequently included by UNESCO in the system of biosphere reserves of the world and in the List of World Cultural and Natural Heritage. There are alligators, turtles, otters, and various wading birds. Adjacent to the national park from the northwest is the Big Cypress Nature Reserve, created in 1974 as a water protection zone that ensures the flow of fresh water within the Everglades. The central part of the park is occupied by the vast shallow Lake Okeechobee, which previously overflowed its banks during strong winds and flooded the surrounding lowlands. Currently, diversion channels have been built from the lake to prevent flooding. Large areas of swamps outside the protected area were also drained, which disrupted the peculiar natural systems of this peninsula, led to the impoverishment of the organic world and deprived the few groups of Indians who lived by hunting and fishing in its interior areas from the basis of existence.
The natural conditions of the Coastal Plains are favorable for subtropical agriculture. Large areas in the recent past they were occupied by cotton plantations. This is the so-called “cotton belt”, stretching on both sides of the lower Mississippi. But now cotton is gradually being replaced by sown grasses, peanuts, vegetables and fruit crops. In the humid areas of the hot southern coast, rice, sugar cane, and tobacco are cultivated (in the southeast). Large areas are occupied by citrus plantations and vineyards. Florida is the largest resort area in the United States.
A significant role in the formation of modern landscapes of the Coastal Plains is played by the rapid development of industry, the extraction of oil and other minerals, and the growth of cities both on the coast itself and in the interior of the region.
Select a climate feature characteristic of the subtropical zone:
A. There is approximately the same temperature throughout the year.
B. Two air masses dominate during the year.
B. Precipitation falls primarily in the form of snow.
D. Trade winds blow all year round.
This continent can be called the driest:
A) Africa, B) South America, C) Australia, D) Antarctica
The highest waterfall in the world is located in the basin of this river.
A) Congo, B) Amazon, C) Zambezi, D) Orinoco.
The most live here tall people(Karamojongs) and the shortest (pygmies)
A) Africa, B) South America, C) Australia, D) Eurasia.
Africa is separated from Eurasia by:
A) Strait of Gibraltar, B) Isthmus of Suez, C) Bosphorus Strait, D) Panama Canal.
Select a lake located in South America:
A) Tanganyika, B) Victoria, C) Titicaca, D) Air.
Trade winds are:
A. Constant winds blowing from 30 latitudes to the equator
B. Winds blowing from the ocean to land in summer
B. Winds blowing from the sea during the day
D. Winds caused by tides
Borders lithospheric plates, direction and speed of their movement, zones faults on land And on the bottom of the oceans are indicated on:
A. Map of natural areas. B. Physical map.
B. Comprehensive map. G. Tectonic map.
9. Air temperature decreases from the equator to the poles, as it changes:
A. Angle of incidence of sunlight.
B. Air composition.
B. Thickness of the troposphere.
D. Direction of constant winds.
10. In what part of North America are the Appalachian Mountains located?
A) Northern, B) Southern, C) Western, D) Eastern.
PART - 2 (8 points)
1.Atlantic Ocean A. Yellow Sea
2.Pacific Ocean B. White Sea
3. Indian Ocean B. Black Sea
4.Northern Ice intertwined ocean G. Red Sea
AT 2. Match the continent with the animals living there
Africa A. Echidna
Australia B. Coyote
South America V. Capybara
North America G. Okapi
AT 3. Which three of the following rivers are located on the North American mainland?
1. Parana 5. Mackenzie
2. Mississippi 6. Orinoco
3.St. Lawrence 7. Zambezi
4. Murray, 8. Orange
AT 4. Match the continent with the plant growing there
1.Africa A. Eucalyptus
2.Australia B. Baobab
3.South America V. Sequoia
4.North America G. Ceiba
PART -3 (4 points)
Why are swamps common on the Florida peninsula? Please provide at least two reasons.
Why is there a sharp drop in air temperature (down to - 10° C) on the Gulf Coast in winter?
TOTAL-22 POINTS
“5” - 20-22 POINTS
“4” - 17-19 POINTS
“3” - 12-16 POINTS
“2” - 11 POINTS OR LESS
Input diagnostic work on geography in 8th grade
Option No. 2
Part I (Tasks A1-A10)
The tasks contain 4 answer options. Only one of them is correct. (10 points)
1.This continent can be called the hottest:
A) Africa, B) South America, C) Australia, D) North America.
A) Amazon, B) Congo, C) Mississippi, D) Yenisei.
3. The highest peak on Earth is a mountain:
A) Aconcagua, B) Kilimanjaro, IN) Chomolungma, G) Elbrus.
4.What explains the high salinity of the Red Sea?
A. Strong evaporation in desert tropical climates
B. Features underwater world
B. Near the Sahara Desert
D. Severe water pollution.
5. Trade winds in the Southern Hemisphere deviate to the left and blow from southeast to northwest, as their direction is influenced by:
A. The Earth's revolution around the Sun
B. Rotation of the Earth around its axis
B. Changes in precipitation in tropical and equatorial latitudes
D. Direction of large mountain ranges
The main importance of the ozone layer for the Earth is that it:
A. Protects the Earth from falling cosmic bodies
B. Delays ultraviolet radiation from the sun
B. Protects the Earth from overheating
D. Promotes the water cycle in nature
In the subequatorial climate zone of the Northern Hemisphere, air masses operate in winter:
A) Equatorial, B) Temperate, C) Tropical, D) Arctic.
Wind direction climate map show:
A) Isolines, B) Arrows, C) Color background, D) Numbers.
In what part of Africa are the Atlas Mountains located?
A) Northern, B) Southern, C) Western, D) Eastern.
What climate zone is there in South America as opposed to Africa?
A. Tropical B. Subequatorial
B. Subtropical D. Temperate
PART-2 (8 points)
IN 1. Establish a correspondence between the sea and the ocean to which it belongs
1.Atlantic Ocean A) Baltic Sea
2.Pacific Ocean B) Chukchi Sea
3. Indian Ocean B) Red Sea
4.Northern Arctic Ocean D) Sea of Japan
AT 2. Choose three correct answers that characterize the natural area - steppe
1.The zone consists of coniferous forests.
2. Trees such as oak, hornbeam, and beech grow on the territory of the zone.
3. Moss and lichen flora are characteristic, and shrubs also grow.
4. Open, flat landscapes predominate. Various grains grow.
5.Vegetation is quite sparse, absent in places, a typical plant is saxaul.
6. There is almost no vegetation, only lichens and mosses are found.
7. The soils are predominantly chernozems.
8. Mostly plowed.
VZ. Insert the missing words in the text according to their meaning and write them in order:
North America is entirely located in both ____________ and __________ P gannets. In the east of the continent there are mountains __.The most high point The mainland is located in the mountains, it is _________.
AT 4. Match the continent with the animals living there
1.Africa A. Koala
2.Australia B. Skunk
3.South America V. Gorilla
4.North America G. Lama
PART - 3 (4 points)
C1. Why is the Barents Sea significantly warmer than the White Sea?
C2. Why are the daily temperature ranges large in the Sahara?
TOTAL - 22 POINTS
“5” - 20-22 POINTS
“4” - 17-19 POINTS
“3” - 12-16 POINTS
“2” - 11 POINTS OR LESS
A. The peninsula has a flat topography, so runoff is negligible
B. A large number of precipitation (or the amount of precipitation exceeds its evaporation).
3. Why is the Yamal Peninsula, with low precipitation, characterized by high swampiness? Give two reasons.
A. The amount of precipitation exceeds its evaporation or low evaporation
B. Permafrost prevents moisture seepage
4.It is considered that the average salinity surface waters The Atlantic Ocean is the largest compared to other oceans. However, in the Gulf of Guinea it is lower. Give two reasons.
A. The Niger and Congo rivers flow into the Gulf of Guinea, which desalinate the waters of the gulf.
B. The Gulf of Guinea is located in equatorial belt where there is a lot of rainfall.
5. Salinity ocean water in the Gulf of Guinea is lower than in the Persian Gulf. Give two reasons.
A. The Niger and Congo rivers flow into the Gulf of Guinea, which desalinate the waters of the gulf.
B. The Gulf of Guinea is located in the equatorial belt, where there is a lot of rainfall, and the Persian Gulf is located in tropical zone, where precipitation is much less.
6. Why is the average salinity of surface waters Baltic Sea significantly below the average salinity of the Atlantic Ocean. Give two reasons.
A. Rivers flow into the Baltic Sea, which have a desalination effect
B. The Baltic Sea is inland or the Baltic Sea has a weak connection with the ocean.
7. The soils of the steppe zone have a much thicker humus horizon and high humus content than the soils of the taiga zone. What explains this? Give two reasons.
A. More precipitation falls in the taiga than in the steppe, so humus in the taiga is washed out into the lower horizons.
B. There is more plant litter in the steppe zone than in the taiga.
8. What are Negative consequences deforestation on the southern slopes of the Himalayas? Give two reasons.
A. Soil erosion increases or landslide processes intensify
B. Floods during monsoon rains become more severe or the ability of soils to retain moisture decreases.
9. What are the negative consequences for environment could it be possible to build a cascade of power plants on a flat river? List two consequences.
A. The construction of a cascade of power plants on a lowland river could lead to that fertile floodplain soils will be taken out of circulation or soil waterlogging will occur due to rising groundwater.
B. Fish catch will decrease significantly.
10. Scientists from many countries warn of danger global warming. According to their calculations, by the end of the 21st century, air temperatures will increase by 6 °C, and sea levels will rise by 88 centimeters. Explain the reasons for possible climate warming and sea level rise.
A. The amount in the atmosphere increases carbon dioxide due to the combustion of mineral fuels
B. Melting of mountain and ice sheets leads to rising sea levels
11. Why on the western slopes of the Andes at a latitude of 50° the snow line is more than 3000 m lower than at a latitude of 20°.
A. There is more precipitation at latitude 50° than at latitude 20°
B. At the same latitude the climate is colder than at latitude 20°
12. Why natural area steppes in Volgograd region gives way to deserts and semi-deserts of the Astrakhan region?
A. Due to less rainfall
B. Due to higher summer temperatures
13. Why on June 30 on the Arabian Peninsula the amount of total solar radiation more than the Malay Peninsula?
A. On the Arabian Peninsula the angle of incidence of the sun's rays is greater
B. Air transparency is higher on the Arabian Peninsula
B. There is more cloudiness on the Malacca Peninsula
14. It usually falls on the ocean coasts. significant amount precipitation. However, on the western coasts of continents in tropical latitudes there is little precipitation. Why? Give two reasons.
A. Along western shores continents in tropical latitudes there are cold currents
In winter, the East European Plain is influenced by westerly winds coming from the Atlantic. In winter, Atlantic air is the main source of heat. That's why winter temperatures change from west to east, it is in this direction that the continental climate increases, i.e. increasing severity of winters. Yaroslavl is located west of Perm, so it is warmer there.
16. The cities of Voronezh and Orenburg are located at approximately the same latitude and approximately same height above sea level. However, the average monthly temperature in January in Orenburg is significantly lower than in Voronezh. Explain why this is happening, giving one reason.
In winter, the East European Plain is influenced by westerly winds coming from the Atlantic. In winter, Atlantic air is the main source of heat. Therefore, winter temperatures change from west to east; it is in this direction that the continental climate increases, i.e. increasing severity of winters. Orenburg is located east of Voronezh, so it is colder there.
17.The average salinity of the World Ocean is 35%o, but it varies in its waters. For example, in the Baltic Sea the average salinity is below average: in the straits connecting the Baltic Sea with the ocean it is 17-20%o, in the central part of the sea - 6-8%o, in the Gulf of Bothnia 2-4%o. Why is the average salinity of the waters of the Baltic Sea lower than the average salinity of the waters of the World Ocean? Give two reasons.
Water erosion.
20. The creation of a reservoir on the river put an end to the spring floods downstream, but after some time the owners of farms located downstream began to complain about the decrease in the productivity of land located below the river. Could this be a consequence of the construction of a reservoir? Justify your answer.
The city of Nizhniye Sergi is located in Sverdlovsk region. In winter, an anticyclone with downward air movement usually dominates there. The position in the intermountain basin further contributes to the stagnation of air in the ground layer and the accumulation of harmful substances in it.
22. What negative consequences can it cause? fast growth city located on the river bank, for rural areas located downstream settlements? Justify your answer.
In addition to the possible increase in river water pollution from domestic and industrial sewage effluents, it is possible that river floods may increase during rainy periods and snowmelt and the river may become shallower during dry periods. summer period. Such consequences may be associated with the destruction of natural vegetation in the river basin and its replacement with paved roads - this will lead to a decrease in underground flow, which regulates the river, and an increase in surface flow.
23. What negative consequences can cause deforestation on slopes? Caucasus Mountains? List at least two consequences.
Deforestation leads to a decrease in the ability of the soil to retain moisture, increased surface runoff, therefore, in mountainous areas, the destruction of forests on slopes leads, on the one hand, to increased river overflows, causing floods, and on the other hand, to increased water erosion, the development of landslides, which damages agricultural lands and populated areas.
24. Deforestation leads to numerous negative changes in nature. Name possible unfavorable changes in river regimes associated with human deforestation in river drainage basins. List two consequences. If you list more than two consequences, only the first two listed will be evaluated.
Forest vegetation delays surface runoff during rains or snowmelt and allows water to seep underground. Deforestation leads to an increase in the intensity of surface runoff and a reduction in underground flow. Because of this, the intensity of floods and floods increases, which can lead to floods, and the water level in rivers during low water periods, on the contrary, becomes lower, which can complicate navigation or the provision of water to consumers.
25. In the tropical latitudes of the Southern Hemisphere, on the western coasts of the continents of South America, Africa, and Australia, there are deserts. What are the causes of such deserts? Give two reasons.
A. In tropical climatic zones, high Atmosphere pressure. The air sinks down and is removed from saturation with moisture.
B. Another reason is the passage of cold currents along the coast. They also do not contribute to the formation of precipitation.
26.On high peaks Glaciers form in the Andes Mountains. They are especially numerous in temperate latitudes on slopes facing the Pacific Ocean. Explain why glaciers form on the tops of the Andes in temperate latitudes.
A. In temperate latitudes, westerly winds dominate, which carry moist air from Pacific Ocean. When it collides with mountains, moist air rises, cools, and precipitation occurs.
B. Since air temperatures are low high in the mountains, precipitation often falls in the form of snow; during the warm season, the fallen snow does not have time to melt, it accumulates, and glaciers form.
27. The Alps and Scandinavian mountains are located in Europe. The number of altitude zones and diversity of landscapes in the Alps is greater than in the Scandinavian mountains. Explain the reason for the difference in the number and composition of altitudinal zones of these two mountain systems.
A. permafrost.
A. harsh winters with little snow, short summer
B. average annual temperature below 0°C.
2. Why are swamps and wetlands common in the Florida peninsula? One of the reasons is the spread of waterproof (silt and clayey) sediments. Give two reasons.
