Located in two: North American and Caribbean. The largest of them is the North American Plate, on which almost the entire continent is located, as well as islands, including. It should be noted that the western boundary of the plate passes through the territory in such a way that the northern tip of Russia, geologically, is also part of the North America... The Caribbean Plate includes the south of the continent, as well as the islands. Here tectonic activity is most pronounced, as there is an active collision of the plate with the North and South American plates.
The northern one can be divided into three parts: the western mountainous, the ancient platform and the eastern one related to the ancient folding. The western one was formed mainly in the Mesozoic and includes the Cordillera, some of its parts continue to form today. The platform includes Greenland, Canadian Shield, Labrador, Center of North America. Ancient folding dates back to the Hercynian age and is represented by the Appalachians, the Atlantic and Mexican lowlands.
The most tectonically active regions of America are located on its west, from the Aleutian Islands to the Isthmus of Panama. Most of the volcanoes are also located here, many of them remain active, such as: Momotombo, Tahumulko, Orizaba, Popocatepetl, Colima, Shasta, Rainier, Sanford and Velyaminov volcano in Alaska. There are also a number of tectonic faults in the area of which there is a constant threat of earthquakes. The most famous of these is the San Andreas Fault. The danger of this rift lies in the fact that next to it are located big cities The United States - primarily San Francisco and Los Angeles. There have already been destructive earthquakes here, however, over the past decades, cities have grown significantly, so that new ones of this kind today will lead to colossal destruction. Another dangerous volcano is a dormant volcano on the territory of the first national park - Yellowstone. Today the volcano manifests itself only in the form of more than three thousand geysers in the park, which is the most beautiful and unique natural monument. One of the most famous geysers is the Old Faithful, which has erupted on average every 90 minutes for many years (Pictured). However, according to forecasts of geologists, in the event of awakening Yellowstone volcano, an explosion will occur, exceeding the power of the eruption of Krakatoa, and the consequences of this eruption will be reflected on the entire planet. Fortunately, such cataclysms occur on Earth no more often than once every several tens of thousands of years. As noted above, a very large seismic activity characterize the islands Caribbean... The last scary
The landscape of North America has been shaped by a variety of geological processes. Some of them continue to this day. What are the features of the relief and its specificity - the presented material will help to answer these questions.
Relief of North America
The relief of North America is diverse and contrasting. The mainland lies on the lithospheric plates - North American and Caribbean. The western boundary of the last plate passes through Eurasia.
In the central area there are flat plains, which alternate with vast hilly areas. In the east, they are adjacent to the Appalachian Mountains. In the west, the plains adjoin the Cordillera mountains.
The features of the relief of North America are due to the specifics of the geological development of the territory, which is 4.5 billion years old.
Rice. 1. Relief map of North America
The ancient North American plateau is the original foundation of the continent, whose relief is expressed by plains differing in height, the shapes and outlines of which resemble waves.
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External processes played a central role in the formation of the relief. Many millennia ago, the areas that are located in the northern part of the mainland were a glacier.
The glacier that existed at that time was twice the area of Australia, and the power was such that this giant easily polished the surface of the rocks and leveled the earth under it.
The following factors influenced the formation of the landscape:
- the impact of surface and ground waters;
- wind.
Relief structure of North America
The structure of the continental surface is divided into the following parts: northern and central, where the plains are located, the eastern - with the Appalachian mountains, and the western - with the Cordilleras. It is the largest mountain range in the world.
In the northwestern part of the mainland large forms the relief of North America is represented by mountain ranges that reach their maximum heights. Mount McKinley (6193 m) located here is the highest point in the Cordillera and North America.
Rice. 2. Mount McKinley
Together with the South American Andes, these heights make up the longest mountain range in the world - over 18 thousand km!
Mountain building in the Cordillera occurs continuously. This is indicated by the constant activity of volcanoes, which is accompanied by frequent earthquakes. The active volcanoes here are:
- Orizaba (5700 m);
- Popocatepetl (5452 m);
- Colima (3846 m).
Seismically active areas of the mainland are located on the western and Pacific coasts.
Rice. 3. Volcano
Plains are formed on tectonic plates and occupy two-thirds of the surface. South of the Laurentian Upland, the Central Plains stretch with an average elevation of 200-300 m. To the west of the Central Plains along the Cordilleras, the Great Plains stretch in a strip. The surface is dotted with river valleys and ledges into separate massifs and plateaus.
To understand what the relief of North America is, you need to have an idea of the course of processes affecting the surface of the platform, which has been destroyed and leveled many times.
What have we learned?
From the article on geography (grade 7), we learned what factors influenced the features of the relief of North America. What natural processes are taking place in this area. Which part of the mainland is occupied by mountains, and which is plain. Why mountain building is a constant and continuous cycle. We also managed to obtain information about the age of the territory on which the mainland is located. It was possible to find out what explains the diversity and contrast of the relief characteristic of this territory. Clarified the location of the highest peak of the Cordillera and North America.
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summaries of other presentations"Minerals of North America" - Atlanticheskiy okean. Minerals. M A g m a tic e. Mine development. Mississippi low. Relief and minerals. Primo Mexican nizm. Sedimentary rocks. Gold mining. Tectonic map of North America. Appalachian mountains. Sorry. Colorado Canyon. Relief and minerals of North America. Bingham copper mine.
"Characteristics of the natural zones of North America" - Soils of arctic deserts. Indicate the natural zone of North America, where the soils are chestnut and black earth. Features of the placement of natural areas. Tests. Taiga. Natural areas North America. Taiga plants. The climate of the arctic deserts. Broadleaved forests. Plants broadleaf forests... Mixed forests. Navigation guide. Steppe. Taiga animals. Desert animals. Plants of arctic deserts.
"Characteristics of the Inland Waters of North America" - Source of the Mackenzie River. Rivers flowing from the eastern slopes of the Appalachians. Rivers of North America. Slave Lake. Mississippi. Mississippi with the Missouri tributary. Lake Athabasca. Bearish. Niagara River. Inland waters of North America. Large rivers. Length. There are many volcanic lakes in the Cordilleras. Lakes in the north of the mainland. The largest rivers in the Pacific Ocean. Great American Lakes. Great Lakes.
"Inland waters of North America" - The largest rivers in the Pacific Ocean are Columbia and Colorado. Lake Ontario. The Great Lakes form a huge water system. In the north of the mainland is the Mackenzie River. The Columbia River is a beautiful mountain river. Lake Erie is the shallowest of the Great Lakes. Bearish. The Colorado River forms the Grand Canyon. Analyze the atlas map and answer the questions. The basins of which oceans are the rivers of North America.
"Relief of North America" - Working with the map. Coastal ridges. Get acquainted with the structure and relief of North America. Let's remember. We count and compare. We work with text. Orizaba and Popocatepetl. Cordillera. Geological structure... Let's move on to checking. Differences of mountains. Scheme. Sample design outline map... Geological structure and relief. Relief of North America. Relief. Study of the features of the relief. Great Plains. Appalachian
"Rivers and Lakes of North America" - Lake Managua in Central America, in Nicaragua. The area is 19.5 thousand km2. Colombia belongs to the Pacific Ocean basin and feeds on melt water from glaciers. Michigan is the largest lake within the United States North. Lawrence. The depth is up to 236 m. The area of its own catchment is about 90 thousand km2. Erie is a lake in North America, the southernmost in the Great Lakes system. Lake Nicaragua is the largest freshwater body of Latin America.
The United States of America is a state located in the western hemisphere, on the continent of North America. The United States consists of 48 bordering states in the "continental part" and 2 states that do not have a common border with the rest: Alaska - a huge peninsula occupying the north western part the continent of North America; and the Hawaiian Islands in the Pacific Ocean.
In addition, the United States includes some territories in the Caribbean Sea (Puerto Rico, US Virgin Islands, etc.), the Pacific Ocean (Eastern Samoa, Guam, etc.) and a non-state Federal district Colombia.
In the south, the United States borders on Mexico, in the north - on Canada. The United States also has a maritime border with The Russian Federation... From the west, the territory of the United States is washed by the Pacific Ocean, from the east - by the Atlantic Ocean, in the southeast of the United States there is the Gulf of Mexico, the Alaska Peninsula is washed by the Arctic Ocean from the north. Among the US borders, the most common is the so-called geometric (astronomical) type of border. This type includes most of the US border with Canada (including Canada's border with Alaska). The eastern part of the US border with Mexico runs along the bed of the Rio Grande River. The maritime boundaries along the east and west coasts, as well as the border with Canada in the Great Lakes region, are classified as hydrographic. They were drawn along natural (natural) boundaries, taking into account the features of the relief. The western part of the border with Mexico is a straight line connecting two locally defined points, while it crosses the territory regardless of the relief, and, therefore, can be classified as a geometric border.
According to various estimates, the total area of the United States ranges from 9,518,900 sq. km up to 9 826 630 sq. km, which puts it in 4th place or 3rd place in the list of the most big countries the world. China has approximately the same area, which varies greatly depending on whether or not various disputed territories are counted.
Statistical indicators of the USA
(as of 2012)
One way or another, in terms of total area, the United States and China are lagging behind Russia and Canada, but ahead of Brazil.
Relief of the USA
Several large physiographic regions are distinguished on the territory of the United States. East along the coast Atlantic Ocean the Appalachian mountain system stretches. To the west and south of it, the surface is leveled, forming low-lying areas through which flow largest rivers USA. Further to the west, the area passes into the vast plains and prairies, called the Great Plains, which precede the mountainous regions of the Cordilleras. Mountain ranges occupy the entire western part of the country and drop off rather abruptly to the Pacific coast.
Most of Alaska is occupied by the northern Cordillera ridges. The Hawaiian Archipelago is a series of volcanic islands up to 4205 m high.
The Appalachian mountain system stretches for 1,900 km along the Atlantic coast of the United States from northern Maine to central Alabama. According to other sources, the Appalachian system stretches for almost 3 thousand km. from central Alabama to Newfoundland Island in Canada, and its width from east to west ranges from 190 to 600 km. The highest point of the system is Mount Mitchell (2037 m), the prevailing heights are 1300-1600 m. These are one of the most ancient mountains on Earth formed about 400 million years ago, when North America and Europe were part of the single continent of Pangea. The Hudson River divides the system into unequal parts - the northern and southern Appalachians. On the territory of New England, the White Mountains, Green Mountains, as well as the Taconic and Berkshire ranges are distinguished. The southern part includes the Adirondack Mountains, the Catskill Mountains, and the Blue Ridge Range. The Blue Ridge Range is the highest in the system, and the Roanoke River is divided into two parts. To the west of the ridges is the Appalachian Plateau, consisting of the Allegheny Mountains and Plateau in the north and the Cumberland Plateau in the south. The plateau is 1000 km long with a width of 160 to 320 km and is strongly dissected by the tributaries of the Ohio River.
In the southern part of the system is the Great Smoky Mountains Ridge and National Park. To the south of it is the Piedmont Plateau. The height of the plateau is 150-300 m, sometimes there are low ridges and outliers. The most famous is the Stone Mountain granite monolith with a relative height of more than 185 m.
The Atlantic lowland (width from 160 to 320 km, height up to 100 m) is located between the ocean and the Piedmont plateau, from which it is separated by the so-called "line of waterfalls" - a drop in height, due to which numerous rapids and waterfalls are formed on the rivers. The Atlantic lowland stretches from the Chesapeake Bay to the Florida Peninsula.
To the west from Florida to the Rio Grande River, the entire southern coast of the country is occupied by the Mexican Lowland (altitude up to 150 m). In many places the coast is swampy and has a strip of marches. Approximately in the middle of the lowland is the Mississippi alluvial plain, 80 to 160 km wide.
The territory from the Great Lakes in the north and the Mexican lowlands in the south, as well as from the Appalachians in the east and the Great Prairies in the west is occupied by the Central Plains (altitude 200-500 m). In the northern part of the plain they have a hilly moraine relief, while in the middle and southern parts the hills are more gentle and eroded. In the south of Missouri, the Ozark Plateau stands out, consisting of the Springfield and Salem Plateau and the Boston Mountains (height 700 m). To the south of the plateau, across the Arkansas River valley, are the Washito Mountains up to 885 m high.
Great Plains - a strip of steppes between the Central Plains and mountainous regions west of the United States. Great Plains The Great Plains begin at 97-98 ° West longitude and are essentially the foothill plateau of the Cordilleras. The height of the plains increases when moving to the west from 500 to 1600 m.The plateau is highly dissected, in some places the network of valleys is too dense for them economic use... In the north are the Badlands - "bad lands", almost devoid of soil cover. Further south - in Nebraska, the Sand Hills. Kansas is home to the low Smoky Hills and Flint Hills, as well as the Red Hills Upland. The southern part of the plains is occupied by Llano Estacado and the Eduards plateau.
In the western part of the United States, the North American Cordillera mountain system passes, which is a system of parallel ridges stretching from north to southeast and separating them with plateaus, depressions and valleys. The longest chain is the Rocky Mountains (the highest point is Mount Elbert, 4399 m), which includes (from north to south): Lewis Ridge, Absaroka Ridge and Bighorn Mountains, Laramie Mountains, Sangre de Cristo Mountains and San Juan, as well as the Sacramento mountains, which to the south, already on the territory of Mexico, pass into the Eastern Sierra Madre ridge.
To the west of the northern Rocky Mountains are the Kabinet and Bitterroot Ranges, which merge into the Clearwater Mountains and the Salmon River Massif. Salmon River is bounded in the south by the volcanic Columbia Plateau and the Snake River Plain, and to the west across the Health Canyon are the Blue Mountains. Further south is the territory of the drainless Great Basin, on which the Independence Mountains are distinguished, and top part the Colorado River Basin, separated from the closed drainage area by the Wasatch Ridge and the Uinta Mountains. To the south stretches the vast Colorado Plateau, in which rivers cut through many beautiful canyons, which is why the region is home to a large number of national parks such as the Grand Canyon, Bryce Canyon, Arches and Canyonlands.
Along the Pacific coast of the United States, there are a number of mountainous Coast Ranges (up to 2,400 m), which include the Alaska Ridges, ridges in Canada, the Cascade Mountains, the Sierra Nevada, and the Western Sierra Madre in Mexico. Between the Coast Ranges and the Cascade Mountains lies the fertile Willamette Valley. The Sierra Nevada is home to the highest point of the continental United States - Mount Whitney (4421 m). Between this ridge and the Coast Ranges lies the California Valley, which consists of the San Joaquin River valleys in the north and the Sacramento in the south. To the east of the Sierra Nevada, there is a small ridge of the White Mountains and behind it Death Valley. In southern California, the Santa Rosa Mountains fence off the Imperial Valley, bounded to the east by the Sonoran Desert.
Most of the territory of Alaska is occupied by mountain ranges stretching from west to east. The northern part of the state is occupied by the flat Arctic Lowlands, framed in the south by the Brooks Ridge, which includes the De Long, Endicott, Philip Smith and British Mountains. In the central part of the state, the Yukon Plateau is located, along which the river of the same name flows. The Aleutian Range bends in an arc around the valley of the Susitna River and continues in the form of the Alaskan Range, forming the Alaska Peninsula and the Aleutian Islands. The highest peak in the United States, Mount McKinley (6193 m), is located on the Alaska Ridge. The Chugach Ridge, St. Elijah Ridge and Wrangel Mountains stretch along the US-owned coast of the Gulf of Alaska.
Water resources of the USA
Map of average annual precipitation in the continental USA See also: List of rivers in the USA, List of lakes in the USA River flow from the territory of the USA is carried out into the basins of three oceans - the Pacific, Atlantic and Arctic. The main watershed (between the Pacific and Atlantic oceans) runs along the eastern part of the Cordillera, and only a small part of the northern states and Alaska belongs to the Arctic Ocean basin. The meeting point of the three watersheds is located on Triple Divide Peak.
According to TSB data, the average annual runoff layer from the surface of the main part of the United States is 27 cm, the total volume is 1600 km?, And the regime of most of the rivers is irregular, especially in continental regions. The availability of water resources in different parts of the country is uneven - the height of the annual runoff layer in the states of Washington and Oregon is 60-120 cm, in the east (in the Appalachian region) 40-100 cm, in the Central Plains 20-40 cm, in the Great Plains 10-20 cm , and on the inner plateaus and plateaus up to 10 cm.
Large lakes are located in the north of the country - the Great Lakes. Smaller drainless salt lakes are found in the depressions of the Great Basin. Internal water resources widely used in industrial and municipal water supply, irrigation, hydropower and shipping.
The largest freshwater lake system in North America, in the United States and Canada, connected by rivers and canals. Area approx. 245.2 thousand km ?, the volume of water is 22.7 thousand km?. The great lakes proper include the five largest: Upper, Huron, Michigan, Erie and Ontario. Among the smaller ones: St. Mary's, St. Clair, Nipigon. The flow from the lakes takes place along the St. Lawrence River.
Many rivers flow into the Atlantic Ocean from the east coast of the United States, the longest of which originate in the Appalachians and are several hundred kilometers long. The rivers Hudson, Potomac, James, Roanoke, Great Pee Dee, Savannah, Oltamaho and others flow through the Atlantic lowland.
The southern part of the lowland is located in Florida - there are the famous Everglades, Big Cypress swamp, and many karst and lagoon lakes, the largest of which is Okeechobee.
Most of the river flow in the United States belongs to the Atlantic Ocean Gulf of Mexico basin. This drainage basin extends from west to east from the Rocky Mountains to the Appalachians and from the border with Canada in the north. The largest river system is formed by the Mississippi River (3757 km long, 180 km? Annual flow) and its countless tributaries, the largest of which are Missouri (4127 km long), Arkansas (2364 km) and Ohio (1579 km). The Mississippi Delta is located in the center of the Mexican Lowland and juts out into the bay for more than 100 km.
Rivers such as, for example, the Rio Grande, which runs the eastern part of the border between the United States and Mexico, as well as Colorado, Brazos, Trinity, and others flow directly into the Gulf of Mexico. There are several closed drainage areas in the United States, the largest of which is the Great Basin. On its territory there are lakes Big Salt Lake, Utah and Sevir in the east, as well as a number of small lakes in the west: Honi, Pyramids, Winnemacca, Tahoe, Walker, Monet and Owens. This basin also contains the Humboldt River, which has no drain. Also prominent are the Great Divide Basin and the Harney Basin, which contains Lake Malur.
The Columbia River (2,250 km long) with its tributary Snake (1,674 km) forms the largest basin in the northwestern United States. Colombia has an annual flow of 60 km? and has the largest hydropower potential. The Franklin-Roosevelt Reservoir is located on the river near the border with Canada. The southern tributary of Columbia, the Willamette River flows through the valley, which is called the northern analogue of California. The San Joaquin and Sacramento Rivers flow through the California Valley itself, which together flow into the San Francisco Bay.
Another large basin in the western part of the country is formed by the Colorado River (2,330 km), flowing on its way through the world's largest Grand Canyon. Above this canyon is the large Powell Reservoir, below the Mead Reservoir. Colorado flows into the Gulf of California in Mexico.
The largest river in Alaska, the Yukon (3700 km), as well as the Kuskokuim river flow into the bay of the same name in the Bering Sea. Only a small part of the United States belongs to the Arctic Ocean basin. Northern Minnesota and North Dakota are dendrized by rivers that flow through Lake Winnipeg and the Nelson River into Hudson Bay. In addition, northern Alaska rivers such as Noatak and Colville also carry their waters to the planet's northernmost ocean.
USA climate
Climatic zones of the continental United States due to the country's large size, length and wide variety geographic features in the United States, you can find areas with almost any climatic characteristics. Most of the United States (states located north of 40 degrees N) is located in the temperate zone, subtropical climate prevails to the south, Hawaii and southern Florida lie in the tropics, and northern Alaska belongs to the polar regions. The Great Plains to the west of the 100th meridian are classified as semi-desert, the Great Basin and areas around it have an arid climate, and the coastal regions of California have a Mediterranean climate. The type of climate within the boundaries of one belt can vary significantly depending on the relief, the proximity of the ocean and other factors. The favorable climate had a significant impact on the settlement of the continent by Europeans and in many ways contributed to the occupation of the United States in the leading position in the world.
The main component of the US climate is a high-altitude jet stream - powerful air currents that bring moisture from the north of the Pacific region. Moisture-laden winds from the Pacific Ocean are actively irrigating the western coast of the United States. In the northwest, rainfall is not rare throughout the year, and there is more snow in winter than anywhere else in the world. California located to the south receives most of the rainfall in autumn and winter, while in summer it is rather dry and hot, which forms its Mediterranean climate. The Cascade Mountains, Sierra Nevada and Rocky Mountains take up almost all moisture, leaving a rain shadow to the east, which forms a semi-desert climate in the western Great Plains. Death Valley and the Great Basin deserts were also formed by the presence of this shadow. Dry winds of the high-altitude jet stream, falling on the completely flat Great Plains, do not encounter any more obstacles and again gain moisture.
Encounters with saturated currents from the Gulf of Mexico often result in severe storms and thunderstorms. In winter, they cause heavy snowfall on the northeast coast of the United States. The vast, flat plains of the United States are often responsible for extremely rapid, sometimes disastrous, weather changes. The temperature can rise rapidly and also drop rapidly depending on which air masses are "captured" by the high-altitude currents - from cold arctic in the north to warm tropical over the Gulf of Mexico.
Natural disasters
A relatively large number of various natural disasters occur in the United States every year.
On the one hand, droughts in the United States are rare, on the other hand, when they do, they have serious, sometimes disastrous consequences. As an example, we can recall the terrible drought of 1931-1940, also known as the Dust Cauldron, which also fell on the period of the most severe economic crisis - the Great Depression. Farms in the Great Plains region actually ceased to function, the region became depopulated (up to 2.5 million people left the plains by 1940), numerous dust storms destroyed the top fertile soil layer. In 1999-2004, another drought was observed in America, comparable in consequences to the one described above.
Frequent tornadoes are a well-known feature of the North American climate; in fact, the United States is far ahead of any other country in the number of tornadoes. The collision of air masses with very different temperatures is the main cause of frequent thunderstorms and tornadoes in the central regions of the United States in spring and summer. Although tornadoes in America are found in various regions - and in the lowland regions of Canada, and on the east coast of the United States and on the Florida Peninsula, it is still the most frequent and strong tornadoes take place in the so-called Tornado Alley, the conditional boundaries of which cover the north of Texas, Oklahoma, Kansas, part of Missouri, Arkansas and Tennessee. In the cities of these states, there are special sirens warning of the appearance of a tornado, and even during construction, houses are equipped with anti-tornado shelters.
Another natural disaster common in the United States is hurricanes. The east coast, the islands of Hawaii, and especially the southern states of the United States bordering the Gulf of Mexico are most affected by this disaster. The hurricane season in the United States begins in June and ends in early December, with its peak occurring between August and October. Some of the most devastating hurricanes include the 1900 Galveston Hurricane, the 1992 Hurricane Andrew, and the terrible Hurricane Katrina that swept through the southern United States in 2005. On the west coast of the United States, echoes of Pacific typhoons are occasionally observed, most often in the form of heavy, prolonged downpours.
Floods, like droughts, are not common in the United States. However, it is worth noting the Great Mississippi Flood of 1927 and the Great Flood of 1993 - extremely long and severe floods that carried away a lot of human lives and costly to the American economy. Many floods are also a direct consequence of hurricanes. It is especially worth noting the floods, which are developing extremely rapidly due to the features of the relief of some areas of the United States. A sudden thunderstorm can instantly fill the canyon, raising the water level by several meters at once. In the state of California, due to heavy rains, landslides also occur systematically.
The western coast of North America is part of the so-called Pacific Volcanic Ring of Fire - the source of 90% of all earthquakes on earth. The entire mountainous region, from the Alaska Peninsula to southern California, is a zone of increased volcanic activity. The concentration of volcanoes is especially high in the Cascade Mountains in the northwestern United States. The 1980 eruption of Mount St. Helens was one of the most destructive in the United States. The islands of Hawaii are also famous for their volcanoes, for example, the Kilauea volcano has been erupting continuously since 1983. However, Hawaiian volcanoes do not pose a particular danger to the residents of the state. The states of Alaska and California, due to their location on the edge of the Ring of Fire, are prone to particularly strong earthquakes. The 1906 San Francisco earthquake and the 1964 Alaska earthquake were among the worst in history. In addition to large devastating earthquakes, these states experience weaker impacts on a fairly regular basis, so all buildings have to be built to be earthquake resistant. Tsunamis are also direct consequences of earthquakes, often hitting the western coast of the United States.
Recently, due to dry summers, the state of California has been hit by wildfires every year.
Statistics
Arctic conditions prevail in the tundra of northern Alaska, the minimum temperature recorded in these parts was -62 ° C. The most high temperatures on the territory of the United States were recorded in Death Valley in California, the thermometer there rose to 56.7 ° C, this is only one degree less than the world record recorded 9 years later in the Sahara.
The western states of the United States are known for their snowfalls, and on average it receives much more snow than anywhere else on earth. In the winter of 1998-99, about 29 meters of snow fell at one of the ski resorts in Washington state. The rainiest place in the United States is Hawaii, with 11 684 mm of precipitation falling annually on the island of Kauai. In the Mojave Desert, on the other hand, the amount of precipitation is extremely low - an average of 66.8 mm per year.
The highest point in the United States is Mount McKinley in Alaska, its height is 6194 m (according to USGS). The lowest is Death Valley, County Inayo, California (-86 m).
Flora of the USA
Various climatic zones pass through the territory of the United States, and in some corners of this vast country a truly unique microclimate has developed, in which an amazing flora has been formed.
Of course, the economic development of the North American continent has played a role, but quite large areas, about 30%, are currently covered with forests. Mainly conifers predominate - spruce, pine, fir. In the northeast of the country, there are massifs of mixed forests, where, in addition to conifers, oaks, maples, plane trees, birches, ash trees, and sycamore trees grow. The Mojave Desert also has peculiar forests - cactus. In Alaska, the northernmost state of the United States, only mosses and lichens grow, in deserts and semi-deserts - shrubs, yucca, wormwood, quinoa, in alpine and subalpine meadows - heather and other flowering plants. Closer to the south, there are magnolias and rubber plants, on the coast of the Gulf of Mexico - mangroves, on the west coast - citrus trees, and in Hawaii - tropical jungle with palms, vines, orchids and other exotic flora. The vegetation of national parks and reserves is also unique. In Yellowstone National Park, which has existed for more than 130 years, there are 1,870 plant species, of which the overwhelming majority are native species.
Most of the forest areas of the park are covered with twisted broad-coniferous pine. Also among the conifers can be noted Douglas fir, white pine, Menzies' pseudo-lamb, Weymouth mountain pine. Deciduous trees grow in the undergrowth: birch, willow, aspen. Only in Yellowstone National Park can you find sand-loving abronia and agrotis cereal. In the Everglades National Park there are more than 2000 species of plants (different types of mangroves, mahogany, oaks, willows, cypresses, pines, ficuses, ink tree, etc.). Also, tropical swamps with 25 species of orchids have been preserved in their original form.
Zion National Park is home to mixed and coniferous forests desert and coastal vegetation - 450 species in total. There are 1,600 plant species in Yosemite National Park, of which 160 are endemic. Next to it is the Sequoia Park, where the tallest trees in the world grow. The tallest sequoia called "The Height of Hyperion" has a height of 115.5 meters. The world's northernmost rainforest area is located in Olympic National Park. It is also the wettest area on the United States mainland.
Fauna of the USA
The rich fauna of the United States is mainly due to the vast expanses and careful conservation of nature, which already had to suffer many troubles from man.
The fauna of the USA, although it has some similarities with the European one, however, the North American mainland also has its own unique animals. Animals common to Eurasia include deer, elk, wolves, hares, sables, ermines, wolverines, woodpeckers, owls, etc. Unique North American animals are porcupines, martens, elk, large flying squirrels, red squirrels, etc.
The nature of the animal world is mainly determined climatic conditions and vegetation. In deciduous forests, black bears (baribals) and grizzly bears, Virginia deer, red lynxes, cougars, possums, skunks, and chipmunks are common. The mixed forests are home to brown bears, lynxes, martens and wolverines. In Alaska, seals and walruses are rookery. In the steppes, in addition to large artiodactyls (bison, deer, pronghorn antelopes, bighorn sheep), there are foxes, coyotes, badgers, ferrets. Bison were mercilessly exterminated by man for the sake of valuable skins, but at present they are under the protection of the law. The deserts are inhabited mainly by small mammals (marsupial rats, etc.), reptiles (snakes, lizards, iguanas), as well as insects (scorpions, spiders, etc.). Crocodiles and alligators, as well as anteaters, arboreal porcupines and monkeys are found in the rainforests of the Gulf Coast. In reservoirs, nutria, muskrats, beavers live, as well as amphibians - frogs, toads, newts.
The birds found in the United States are very diverse. In the middle latitudes, you can watch owls, vultures, eagles, mockingbirds, cranes, snipes, peregrine falcons, cormorants. In the south of the country, there are more exotic species - parrots, flamingos, pelicans, hummingbirds.
The fish world is mainly represented by salmon - there are 18 species of them in the Yellowstone Reserve alone. Near the Hawaiian Islands, 600 species of tropical fish coexist with turtles.
Extensive national parks and nature reserves help preserve the enormous species diversity of the United States' wildlife. The greatest species diversity of mammals, birds, fish and insects can be found in the national parks of Yellowstone, Everglades, Zion (about 300 species of birds), Bryce Canyon (60 species of mammals and 160 species of birds), Santa Ana (the largest bird sanctuary). The world-famous Yellowstone Wildlife Sanctuary contains the largest populations of bison, grizzly bears, cougars and wolverines. In the Everglades National Park, where tropical swamps have been preserved, Mississippi alligators and sharp-nosed crocodiles coexist, as well as numerous species of birds, including exotic ones.
Due to the variety of relief forms, North America has large reserves of minerals, many of which are classified as rare.
Mainland plains
The mainland plains are located on the very ancient North American Platform, which consists of Precambrian crystalline shields. The Northern Plains are located within the Canadian Shield.
A large number of freshwater lakes are located on these plains, which form the southern and western border of this shield. The lakes were formed here due to hollows of gouging during the Ice Age.
To the south are the central plains, the average height of which is 200 m above sea level. These plains are composed of continental and marine rocks.
In the far south, the central plains give way to the Mississippi Lowlands. From the central plains to the foothills of the Cordeliers, the vast expanses of the Great Plains stretch.
These plains have a stepped shape, their height above sea level increases in a westerly direction.
Mountains of north america
The Appalachian Mountains are located in the southeast of the mainland. They belong to the category of revived folded - block mountains, which were formed during the era of the Hercynian orogeny. The highest point of this mountain system is Mitchell Peak, which reaches a height of 2300 m.
The Appalachian mountains are characterized by rounded peaks and gentle slopes. The Cordillera are located along the Pacific coast of North America.
The Cordelier mountain system is divided into two parts, which are connected by highlands and high plateaus. The highest peak The Cordelier is Mount McKinley (6195 m).
The formation of the mountain system took place in two stages. The formation began in the Mesozoic era, and finally the mountains were formed in the Middle Cenozoic.
The Cordelier mountain system includes the volcanic Mexican Highlands, the Colorado Plateau, the Mexican Plateau, and the Great Basin Plateau.
Minerals of North America
In the bowels of North America there are huge reserves of a wide variety of minerals. Large reserves of non-ferrous and ferrous metal ores, nickel, uranium and gold are concentrated in the northern territories of the mainland.
The largest iron ore industrial region is located on the shores of Lake Superior. Oil-bearing areas are located in Alaska, on the shelf and coast of the Gulf of Mexico, in the Great Plains, on the coast of the Arctic Ocean.
In the valleys of the Appalachians, there are pools of coal. Springs of non-ferrous metal ores are concentrated in the Cordeliers: silver, zinc, lead and copper, as well as phosphorites. The flat areas are rich in natural gas.
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