Physical Description of North and South America - Term Paper Example

PHYSICAL OF NORTH AND SOUTH AMERICA INTRODUCTION Central, North and South American continents, often referred to as the Americas, constitute what is referred to a supercontinent. Each is considered a subcontinent. In terns of ancestral roots, Canada and USA are considered North America (or Anglo-America), and the central and south America and Caribbean islands Latin America. Both continents constitute what was referred to Europeans as New World. NORTH AMERICA The North American continent is the largest of the two continents in the northern hemisphere and the third largest continent on earth. It is bounded to the north by the Arctic Ocean; the Atlantic to the east; the Pacific to the west; and the Caribbean Sea, Atlantic and Pacific oceans. It as well bordered by South America at the Panama tip. The continent has a landmass of over 24, 000 km2. Most of the continent’s landmass is occupied by three countries (Canada, Mexico and USA). Thirty-four smaller islands in the Caribbean Sea constitute the remaining part of the continent. Topography and Drainage System North America has eight topographical regions. The regions have uniformity in climate, vegetation, soil, relief and environmental conditions. The Gulf and Atlantic Coastal plains form the flattest lowlands of the interiors of North America. They are relatively geologically young (about 70 million years) and formed as a result of sedimentation of eroded rocky materials washed out from the Appalachian Mountains, the Central lowlands and the Great Plains. The plains are quite extensive. The region is well endowed in crude oil due to deposition of coastal marine life. The region has battery of swamps, marshes and lagoons in the transition zone between land and sea. The second region is the Appalachian Highlands. This region is by-product of Appalachian mountain ranges, which was a creation of the collision of the North American continent with Europe and Africa. Continental and oceanic plates were forced to move as a result of tectonic activities causing intense folding of sedimentary rocks. Furthermore, the remaining part of the continent is divided into four topographical regions. These are the Great Plain, which stretches from the Gulf of Mexico to the Canadian Arctic; the geologically young, mountainous west, including the Rocky Mountains, the Great Basin, California and Alaska; the raised but relatively flat plateau of the Canadian Shield in the northeast; and the varied eastern region, which includes the Appalachian Mountains, the coastal plain along the Atlantic seaboard, and the Florida peninsula.[9] Mexico and its long plateaus and cordilleras fall largely in the western region, although the eastern coastal plain does extend south along the Gulf. The drainage system of North America comprises two components. These components are sourced from the Rookies and Appalachians. There five Great Lakes (Erie, Huron, Michigan, Ontario and Superior) form one component. The river system is the best inland waterway system in the world. It is very navigable year round. The river system comprises of network of rivers which includes rivers such as Mississippi, Ohio, Missouri, Colorado and Columbia. Climate and Vegetation North America extends from about 10°N of the equator to about 10 from the Arctic Pole. The weather in the continent is generally colder northwards to the Arctic. However, diurnal heating and cooling of land and sea causes distortions to this general pattern. This localized effect is cause as result of differential heating and cooling of land and sea surface. Also topography affects the climate and vegetation of the continent. The climate in the mountainous areas is generally colder in the winter and milder in the summer compared to surrounding areas. The natural vegetation of regions areas receiving more than 20 inches of water annually is forest, drier climates give rise to a grassland cover. While most of the climate of the continent can be said to be temperate, tropical (and subtropical) climate is also prevalent in some parts. Generally, thus, the climate varies with latitude. There variety of climatic zones ranging from tropical rain forest and grassland in Central America to areas of permanent ice cap in central Greenland. The northern parts of Canada and Alaska State have subarctic and tundra climates. The western parts of the continent have wetter climate and thicker vegetation than other areas within the same latitudinal range. However, the South-western part of the continent has desert and semi arid conditions. The south-western part of US (covering a large portion of Arizona, Colorado California, Oklahoma, Utah, Texas, Nevada and New Mexico States) and north-eastern part of Mexico (covering parts of Baja California, Nuevo Leon, Coahuila, Chihuahua and Sonora States). The steppes (also called Prairies) in the mountainous areas have warmer climates with averagely low rains. This region has grassland cover. The mountainous ranges of the continent are responsible for the dryness of the greater part of western US. the mountains, there, squeeze out moisture of Pacific wind. The mountains cascades the moisture laden wind and force it to prematurely cool thus causing it to loose its rain-bearing character. Another unique climatic characteristics of North America, especially in central US, is the high frequency of destructive tornadoes. The frontal activities of tropical Gulf air moving northwards and polar air moving southwards, and local weather disturbances created by wide temperature differences produces storms during summers and large amount of snow SOUTH AMERICA Latin America extends from 32.3 degrees North (Northern Baja CA) to 55 degrees South Much, but not all, of South America lies in the tropics (between Tropic of Cancer and the Tropic of Capricorn). A small part of the continent lies outside the tropics (subtropics). It is the fourth largest continent and located in the southern hemisphere. The countries in South American continent are Columbia, Chile, Brazil, Peru, Guyana, Costa Rica, Argentina, Bolivia, Venezuela, Guatemala, Panama, Honduras and El Salvador. There are quite a number of islands that form part of this continent. These include Antilles, Aruba, Lesser, Barbados, Guyana, Suriname, French Guiana and Trinidad. The people of the continent are of different cultural background but Spanish colonial antecedents (with exception of Brazil) symbolically influence their cultures. Physiographic and drainage system. South American continent is divided into three main regions: the Andes, the Eastern Highlands and the Lowlands. These regions are primarily remnants of plate tectonic that resulted in the breaking of the Gondwanaland broke apart into separate continents and the tremendous out-pouring of lava from beneath the earths surface. The Andes is the most prominent topographical region that stretches the length of the entire continent. The highest peak in the Andes, Aconcagua in Chile, is nearly 23,000 feet. The Andes are largely composed of geologically young and active volcanic rocks. They are a result of tectonic activities. The Andes is responsible for the unique climatic, vegetation and hydrological condition in parts of the continent. High and extensive altitude of the Andes causes rain-nearing clouds to deflect rains to the East coast leaving much of the continent dry. This leaves the greater part of the western edge of the Andes dry with few parts of the desert dotted with oases. The Andes is to be geologically active with frequent tectonic (especially earthquakes) occurring. In addition, the drainage system is shaped by the Andes. On the Western slopes of the Andes, shallow rivers with limited water flow westwards towards the Pacific. These rivers lose most of their water on the Eastern side of the Andes largely because of their dry watershed. Rivers on the eastern slopes of the Andes are fuller and longer. They are sourced from eastern slopes of the Andes, where there is abundant rainfall. There are quite a number of rivers that flow eastward of the Andes. The Amazon is however the longest of them. It has more than 1000 tributaries. The river flows about 4000 miles into the Atlantic. The Amazon bears one-fifth of world’s freshwater and 40% of South America. During it seasonal peak, the river overflows its banks floods into an area with the size of England. The Eastern highlands are contrastingly remarkably older and more resistant rocks. The topographical features in the eastern highlands are relics of ancient rocks shaped by erosion. The eastern highlands consist of three major divisions: the Brazilian Highlands, Guiana Highlands, and Patagonian Plateau. The Guiana and Brazilian Highlands are formed on the same basic geological bedrock but separated from each other by eroding waters of the Amazon River. The Patagonian Plateau is less obvious but forms the southernmost end of the eastern highland region. Active erosion has lowered the eastern highlands down to an altitude that ranges from 600 to 4500ft. There are plateaux with rolling hills formed from more resistance rocks on western edge of the Highlands. The steep slopes of the plateaux create magnificent waterfalls on the western edge of the Brazilian Highlands. The rest of the South American continent, excluding the Andes and Eastern Highlands, is categorized as lowland (basins and plains). A number of river basins and plains form the lowlands of South America. Broadly, the lowlands are divided into Amazon Basin, illanos, Gran Chaco and Paraguay-Paraná-La Plata river system and the Pampas. The Amazon is largely dense rainforested lowland characterized by extensive annual flood. It also has a remarkable number of distinctive regions, affected by different micro-climates, elevations, soils, etc. The Gran Chaco is dry lowland with few perennial streams and low agricultural potential. The Pampas is an alluvial plain with adequate rainfall and moderate temperatures. It is a highly productive agricultural region. The Ilanos are the northernmost of the lowlands in the South American continent. This region is a grassy floodplain. The Illanos has not been agriculturally utilized but it contains some oil reserves. Climate and Vegetation The climate and vegetation of South America shows great variety. It ranges from the driest desert in the world to the worlds largest tropical rain forest. There is also variation due to latitudinal location (tropical and subtropical) and altitudinal influence, which collectively results in distinct local climates, soils, faunal and faunal endowments as well as human activities. Generally, the climate and vegetation of the continent can be categorized into rainy tropical, wet-dry tropical and dry areas. The tropical areas are generally hot and humid throughout the year. They are densely forested with little sunlight. The Amazon Basin constitutes this climatic/vegetation region. The wet-dry regions have extensive dry seasons, lower rains, preponderance of shrubs (and savannah in drier areas) and high temperatures. The dry areas have little rain, high temperature and very scanty vegetation. This regions stretches from southern Ecuador to northern Chile. The Atacama desert, the driest place on earth, is located within this regions. A unique feature of South America Climate is the El Nino. The El Nino is El Niño is part of a complex ocean-atmospheric system which is a part of the world-wide climate. It occurs every two to seven years when the cold dry Peruvian sea current weakens and warm waters from the south rush along the coast in a southward direction. The El Nino affects the Climate of South America and causes heavy rainfall in the dry parts of South America. The occurrence of El Niño occurs causes the barometric pressure in the eastern Pacific to fall while that of the western Pacific close to Indonesia and Australia rises. This alternate effect causes dry weather where the air pressure is high and stormy precipitation where it is low. References Maps of Worlds (2009). “South America”. Web. June 2, 2009. www.mapsofworld.com/southamerica #maps of Worlds (2009). “North America”. Web. June 2, 2009. www.mapsofworld.com/northamerica Hazen, Helen (2008). “Making Geography Authentic”. July 17, 2008. Web. June 1, 2009. http://www.google.com/url?sa=t&source=web&ct=res&cd=19&url=http%3A%2F%2Fwww.macalester.edu%2Fgeography%2Fmage%2Fteachers%2Finstitutes%2F2008mohe%2Fcontent%2FHHPhysical%2520Geography%2520of%2520Latin%2520America%2520notes.doc&ei=Cn4nSrfKN43htgeNo7TpBg&rct=j&q=physical+geography+south+america&usg=AFQjCNHPzHrzBuqRnQSmOTfbmcSZqrc1A Read More