The reliefs of america They include great mountain ranges, extensive plains crossed by wide and long rivers and imposing massifs of great antiquity. If you look at the relief map of America, you will appreciate that around the western edge (to the left of the map) there is a long mountain range that goes from the north (above the map) to the south (below).
While on the opposite side, to the east (right), there is a relief made up of discontinuous massifs. They are observed to the east of North America and also to the northeast and east of South America. In the middle of that long mountain range in the west and these massifs in the east, large plains stretch.
This is because the American continent is a land mass made up of two fundamental tectonic plates. These are the North American Plate and the South American Plate, and among them the Caribbean Plate and other smaller ones forming Central America and the islands of the Caribbean Sea..
On the other hand, America extends in a north-south direction from the Arctic Circle to the Antarctic Polar Circle. The plates that make up the American continent arise at the bottom of the ocean in the middle of the Atlantic to the east and then develop towards the west..
These plates then collide with the Pacific Plate, which sinks below America producing uplifts that constitute part of its mountain system..
With all these tectonic movements that cause earthquakes and volcanic eruptions, the ancient massifs of the east arose first. Later, the long mountain range of the west and in the middle the plains and plateaus.
America is a large continent, oriented from north to south, with a mostly high relief, made up of 4 main parts. These are North America or North America, Central America or Central America, the Antilles or Caribbean islands, and South America or South America..
America is the second largest continent after Asia, reaching 42,111,231 kmtwo, being the longest in the north south direction. It has a length of about 15,500 km from the extreme north to the extreme south.
The highest altitude on the continent is the Aconcagua peak in the Andes of Argentina, which reaches 6960.8 meters above sea level. While the lowest part corresponds to the Gran Bajo de San Julián in Argentina, with the Laguna del Carbón at 105 meters below sea level. However, on average a large part of America is above 1,500 meters above sea level..
The American continent is subdivided into 4 subcontinents: South America, Central America, the Antilles, and North America. This corresponds to the tectonic plates that make up America, the two main ones being the North American Plate and the South American Plate..
Then there is the Caribbean Plate, covered by the sea and on the eastern edge of which are the islands of the Antilles. Finally, joining the North and South plates, a series of small plates are found that form Central America..
The orogeny refers to the origin of the relief, more specifically the mountains, and on this continent the oldest are to the east. The plates that form America originate on the ocean floor in the middle of the Atlantic, where new soil is generated by volcanic activity..
From there, the plates extend west (to the left of the map) and collide with the Pacific Ocean plates coming from the east. In that collision line, the Pacific Plate and other minor plates sink below the American plates..
This sinking ocean floor mass presses upward and the edge of the American plates rises. That is why you observe that long cordon of mountains throughout the western part of the American continent that goes from the south in Chile and Argentina to Alaska in the north..
But before that cordon, other land masses rose further east, many millions of years ago in the Paleozoic. They are the massifs that you see on the right of the map.
These massifs are so old that erosion has flattened them a bit, turning them into plateaus and mountains with less steep and even concave tops. While the western cordon being younger, from the Cenozoic, still retains its abrupt relief, with steep peaks and higher altitude.
If you now detail the entire surface located between the long mountain range to the west and the massifs to the east, you can see plains. This is because when the great mountain ranges emerge in the west, heavy rains occur..
This happens because the winds when colliding with the high mountains rise and discharge their humidity. Therefore, in these mountain ranges many rivers are born, which as they join together form larger ones..
These rivers run down the slope to the east, emptying into the Atlantic Ocean and eroding the mountains, carrying large amounts of sediment. When they reach the lower part, they lose strength and deposit the sediments, filling the ground between the western mountain ranges and the eastern massifs, forming the plains..
The longest rivers in America are the Amazon, Paraná, Mississippi, Yukón, Yuruá, Bravo, Purús, San Francisco and Paraguay.
The main reliefs of America are:
In North America, these older massifs lie to the east forming the Canadian Shield. The Appalachian Mountains are located here, stretching from the island of Newfoundland (Canada) to Alabama (USA)..
While in South America there is the Guiana-Brazilian Shield, which includes the Guyanese shield, the Brazilian massif and the Patagonian Plateau..
In the Guiana massif to the north of South America, the tepuis are formed, which we find from Colombia to Venezuela and north of Brazil. These are huge tabular sandstone mountains with a concave top that reach more than 2,000 meters above sea level..
While in the east-central part of South America is the Brazilian Massif, which are a series of plateaus that cover a large part of Brazil. In addition to the northeast of Argentina, the Gran Chaco and the Pampa. This massif limits to the south with the Patagonian Plateau in Argentina, with the mountains called Patagónides that do not reach 2,000 meters above sea level..
The youngest and highest and most rugged mountain ranges that form west from south to north are also the longest. The longest is the Andes mountain range that goes from the extreme south of Chile and Argentina to the north of South America in Colombia and Venezuela. This is the longest mountain range in the world, reaching 8,500 km in length.
Then, in Central America the folding continues with small elevations in the El Darién area, no greater than 1,875 meters above sea level, which are continuous with the Sierra Madre. The latter covers all of Central America to the north of Mexico in North America, the highest Central American elevation being the Tajumulco volcano with 4,222 meters above sea level..
While in the Mexican section the highest elevation is the Pico Orizaba with 5,610 meters above sea level. Later, in western North America the mountain range continues, with the Rocky Mountains in the USA and Canada. The highest point here is Mount Elbert in Colorado (USA), at 4,401 meters above sea level..
In North America are the great North American plains, in English the Great Plains. These form on a plateau that covers southern Canada, the entire central United States, and northern Mexico..
These plains are crossed by large rivers such as the Missouri and the Mississippi, and have an average altitude of 116 meters above sea level and a maximum of 1,680 meters above sea level. For its part, in the rest of Mexico there is the central plateau and in Central America the coastal and intermediate plains.
While in South America there are large flat extensions, such as the Colombian-Venezuelan plains to the north with altitudes that do not exceed 200 meters above sea level. Then in the center you can see the great undulating plain of the Amazon River basin, with altitudes between 100 and 500 meters above sea level and to the south are the chaco and the pampas.
In all the mountain ranges canyons, plateaus and valleys are formed, while in the plains hills and hills arise. In the north of South America and in the islands of the Caribbean there are also minor mountain ranges.
Such is the case of the Venezuelan Caribbean Coast Mountain Range, whose maximum altitude is the Naiguatá peak at 2,765 meters above sea level. As well as the Sierra Maestra on the island of Cuba, with the Turquino peak (1,974 masl) and the John Crow and Blue Mountains in Jamaica, with the Blue Mountain of 2,256 masl.
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