Geography of North America

North America is the third largest continent with an estimated population of around 460 million, ca. 24,346,000 km² (9,400,000 square miles), (if Eurasia is excluded), and the northern of the two continents of the Western Hemisphere.cite web|url=http://www.geographicguide.com/north-america.htm|title=Geographic Guide - Images of North America|accessdate=2006-10-11|] . It is bounded by the Pacific Ocean on the west, the Atlantic Ocean on the east, the Caribbean Sea, Atlantic and Pacific oceans, and South America on the south, and the Arctic Ocean on the north. Canada covers most of the northern half of North America (much of which is sparsely populated). Alaska, the largest state of the U.S.A., occupies the northwestern part of the continent. North America consists of all the mainland and related offshore islands lying north of the Colombia-Panama border according to most sources, or the Panama Canal according to a few. Anglo-America can describe Canada and the USA together, while the northern part of Latin America comprises Mexico, the countries of Central America, and the Caribbean. (For more, see Americas (terminology)).

Its natural features include the Rocky Mountains, the Appalachian Mountains (the largest mountains in the east), the Great Lakes, and the Mississippi, Missouri, Rio Grande, and St Lawrence rivers.

Climate is mainly determined, to a large extent, by the latitude, ranging from Arctic cold in the north to tropical heat in the south. The western half of North America tends to have wilder and wetter climate than other areas with equivalent latitude, although there are steppes (known as "prairies") and deserts in the "United States Southwest" (Arizona, Colorado, California, Nevada, New Mexico, Utah, Oklahoma, Texas), along with the Mexico states of Baja California, Sonora, Chihuahua, Coahuila, Nuevo Leon and Tamaulipas.

History

Physiographically, the continent may be divided into at least five major regions: the Canadian Shield, which is a geologically stable area of ancient rock that occupies most of the northeastern quadrant, including Greenland; the Appalachian Mountains, a geologically old and eroded system that extends from the Gaspé Peninsula to Alabama; the Atlantic-Gulf Coastal Plain, a belt of lowlands widening to the south that extends from South New England to Mexico; the Interior Lowlands, which extends down the middle of the continent from the Mackenzie Valley to the Gulf Coastal Plain including the Great Plains on the west and the agriculturally productive Interior Plains on the east; and the North American Cordillera, a complex belt of geologically young mountains and associated plateaus and basins, which extend from Alaska into Mexico and includes two orogenic belts—the Pacific Margin on the west and the Rocky Mountains on the east—separated by a system of intermontane plateaus and basins.cite web |url=http://www.infoplease.com/ce6/world/A0860021.html |title=North America's Geology and Geography |accessdate=2006-08-19 |last=Jones |first=Steve |publisher=USA Today] . The Coastal Plain and the main belts of the North American Cordillera continue in the south in Mexico (where the Mexican Plateau, bordered by the Sierra Madre Oriental and the Sierra Madre Occidental. It is considered a continuation of the intermontane system) to connect the Transverse Volcanic Range, a zone of high and active volcanic peaks south of Mexico City.

During the Ice Age of the late Cenozoic era, a continental ice sheet covered much of the continent, centered west of Hudson Bay (the floor of which is slowly rebounding after being depressed by the great weight of the ice). Glaciers descended the slopes of the Rocky Mountains and those of the Pacific Margin. Extensive glacial lakes, such as Glacial Lake Missoula, Bonneville (see Bonneville Salt Flats), Lahontan, Agassiz, and Algonquin, formed by glacial melt water. "Remnants of them are still visible in the Great Basin and along the edge of the Canadian Shield in the form of the Great Salt Lake, the Great Lakes, and the large lakes of west central Canada."

Coastal line

The east coast of America resembles the opposite coasts on the other side of the Atlantic. The vast majority of North America is located on the North American Plate, with parts of California and western Mexico forming the partial edge of the Pacific Plate; the two plates meet along the San Andreas fault.

The continent can be divided into four great regions (and sub regions): the Great Plains stretching 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.cite web|url=http://artzia.com/Society/Geography/North_America/|title=Encyclozine - North America|accessdate=2006-10-11|] 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 western mountains have split in the middle, into the main range of the Rockies and the Coast Ranges in California, Oregon, Washington, and British Columbia with the Great Basin (a lower area containing smaller ranges and low-lying deserts) in between. The highest peak is Mount McKinley/Denali in Alaska.

The United States Geographical Survey states that the geographic center of North America is “6 miles west of Bata, Pierce County, North Dakota” at approximately 48⁰ 10′ north, 100⁰ 10′ west, approximately 15 miles (25 km) from Rugby, North Dakota. The USGS further states “No marked or monumented point has been established by any government agency as the geographic center of the 50 States, the conterminous United States, or the North American continent.” [cite web|url=http://stateprofiles.com/?|title=Physical Geography of North America|accessdate=2006-08-19|] Nonetheless, there is a 15 foot (4.5 m) field stone obelisk in Rugby claiming to mark the center. Three countries (Canada, the United States, and Mexico) make up most of North America's land mass; they share the continent with 34 smaller nations located mainly south of Mexico and in the Caribbean.

urface and climate

The Rocky Mountains stretches from north to south, in contrast to South American cordilleras lean on, west, elevated plateaus, which helps to develop large-sized rivers; less high and send to the east more expanded ramifications. The mountain systems do not allow indefinite connection with the cordillera system with exceptions. They lie in chains parallel to the nearest coasts in North America. These are named the Appalachians or Alleghenies.

The Great Plains is the broad expanse of prairie and steppe which lies east of the Rocky Mountains in the United States and Canada. The narrow plains in the Mexican coast and the savannas of the Mississippi are analogous to, respectively, the Patagonian steppes and the pampas of the Piranha, Paraguay, and Rio de la Plata. Thus the Appalachians and the mountain chains of Brazil are regarded as creating similar interruptions to the plains community.cite web|url=http://www.infoplease.com/ce6/world/A0860022.html|title=North America climate|accessdate=2006-08-19|] .

North America extends to within 10° of latitude of both the equator and the North Pole. It embraces every climatic zone, from tropical rain forest and savanna on the lowlands of Central America to areas of permanent ice cap in central Greenland.. Sub arctic and tundra climates prevail in north Canada and north Alaska, and desert and semiarid conditions are found in interior regions cut off by high mountains from rain-bearing westerly winds.. However, most of the continent has temperate climates very favorable to settlement and agriculture. Prairies, or vast grasslands cover a huge amount in mountain ranges.

Below is a list of North America's greatest snowfalls.

[http://www.infoplease.com/ipa/A0001381.html]

Hydrography

River systems

North America has the most extensive lake groups in the world. The Mississippi, or preferably, the Mississippi-Missouri is the largest North American River. [cite web|url=http://www.geographyzone.com/questions/longest_river_north_america.php|title=Longest River in North America|accessdate=2006-08-19|] . Its watershed is convert|1221000|mi2|km2 in area. Also important is the St. Lawrence River, which is drains convert|600000|mi2|km2 and just like the Mississippi system, opens up the "heart" of the continent, while other rivers cross the northern plains.

The Mississippi River is called the Father of Waters since it is one of the largest rivers in the world. Including its major tributary, the Missouri River, which rises in the Rocky Mountains, the Mississippi is convert|3892|mi|km long. Its river basin drains 2/5ths of the Continental United States, which is 1/3 size of Europe. The Mississippi rises in several small lakes in Northern Minnesota at convert|1670|ft|m|abbr=on above sea level. It gets larger, as it flows into the Gulf of Mexico. Then it is joined first by the Missouri River, and next by the Ohio and many smaller rivers flow into it.

High bluffs border the wide stream of the Mississippi in central U.S. It is thought that ancient glaciers melted, and streams fed by melted ice cut the deep valley in the upper Mississippi. Gradually, their streams carved the sloping, wooded hills that goes into the bluffs. Seventeen miles north of St. Louis, the Missouri River joins the Mississippi side by side. A little north at Cape Girardeau, the bluff ends. Next, it flows through its alluvial valley. Along this valley, centuries of mud deposits have built up the bottom and natural levees alongside the river. In places, surface of MS lays above land, which can result in disastrous floods over the riverbank. It has always been a threat to people alongside the river.

From then on, it enters the delta area, which is convert|12000|mi2|km2, and stretches out into the Gulf of Mexico in the shape of a bird's foot (although this shape consists of very low-lying land, which is in the process of getting flooded). In 1882, the U.S. government contributed to the new levee system. They built convert|8|ft|m|abbr=on wide and convert|150|ft|m|abbr=on at the bottom, 15-25 ft high-level banks. As forests chops away and swamps drained, floods increased in the river. (For example, the 1926 flood that lasted along the river and grew higher). The flood covered over almost convert|23000|mi2|km2 of land, killing hundreds of people. Federal and state governments set up a flood control plan that included building stronger and higher levees and creating dams and spillways to divert floodwaters into other channels. Then forests replanted in order to hold moisture in the ground, and curves in the river straightened.

Other main North American rivers include:

*Approaching the Arctic Ocean
**Mackenzie
**Copper Mine
**Churchill
**Nelson
**Severn
**Albany

*Approaching the Atlantic Ocean
**St. Lawrence River
**Tennessee River
**Hudson River
**Delaware River
**Churchill
**Rio Grande
**Saint John

*Approaching the Pacific Ocean
**Colorado
**Yukon
**Fraser
**Columbia
**Sacramento
**San Joaquin

Water

Water is a major natural resource in North America. In addition, there is high runoff and snowmelt on the landscape. Rocky Mountain Rivers and lakes supply water for one-quarter of the United States. The rivers that flow from the Rocky Mountains eventually drain into three of the world's five oceans: the Atlantic, the Pacific, and the Arctic. Some of the most prolific rivers are the Colorado, the Arkansas, the Columbia, the Missouri, and the Yellowstone.

Climate and vegetation

The climate in North America is typically cool and humid. The rainy zone disproportionately extends in America, and as the continent stretches over the climatic zones, vegetation is remarkably distinctive. Great indentations of the shoreline make insular conditions to prevail in much of its interior. The area along the west coast tends to be milder and wetter than other areas with the same latitude.

There are various plant life distributions in North America. Plant life in the Arctic includes grasses, mosses, and Arctic willows. Coniferous trees, including spruces, pines, hemlocks, and firs, are indigenous to the Canadian and Western U.S. mountain ranges as far south as San Francisco. Among these are giant sequoias, redwoods, great firs, and sugar pines. Sugar pines are generally confined to the northwestern area of the United States.The central region of the country has hardwoods. Southern states grow extensive yellow pines. In addition, mahogany, logwood, and lignumvitae - all tropical in nature - are grown. The southwest has desert plants, including yucci and cacti. The cultivated native plants of North America are tobacco, maize, potato, vanilla, melons, cacao, gourds, indigo plant, and bean.

Human interaction

In the Western Hemisphere, remains of coral reefs lie in Florida, which are estimated to be 10,000 years old; and a skeleton dug up in the Mississippi Delta (in buried forests), near New Orleans, is supposed to have lain there 50,000 years ago. These artifacts could prove that man existed in America prehistorically. New mixed races are distinguished by a variety of names ("e.g.", Mestizos, Mulattoes, and Zambos), and native ancestors of European parents called Creoles. [cite web|url=http://www3.nationalgeographic.com/places/continents/continent_northamerica.html|title=National Geographic Society - North America|accessdate=2006-10-11|] .

In 1960, the population of North America estimated at 405,000,000 persons. North America is the fourth largest continent by population.

Zoology

North America is home to many native mammal species. Several species of deer, including elk, caribou, moose, mule deer, and the abundant white-tailed deer are found throughout various regions, along with the bison and musk ox in the central and northern plains, respectively. Three species of bear, several subspecies of wolf, and various other carnivores such as raccoons, skunks, and cats including cougars and lynxes are widely distributed. The family Mustelidae is well-represented, including badgers, otters, ferrets, and wolverines. Numerous species of squirrels and other rodents, such as beavers and muskrats, can be found in virtually every region of the continent. Central America has adapted sloths, anteaters, and armadillos. Other animals includes the condor, among the heights of the Andes, the parrots and the monkeys of Tropical forests, the humming bird, rattlesnake, alligator, and Cayman of the banks of the streams, the electric eel in the tropical waters, and swarms of mosquitoes on the wide plains.

Mineralogy

More than any other area in the world, North America produces the most metals and minerals used by man. Thus this makes Canada, the United States, and Mexico some of the richest regions in the earth.cite web|url=http://www.factmonster.com/ce6/world/A0860024.html|title=Fact Monster - North America: Resources and Economy |accessdate=2006-10-11] . However, in the Rocky Mountains mineral resources are often scarce.

Rocky Mountains

The Rockies known for it is the vast amount of resources has rich minerals that include bauxite, copper, lead, gold, silver, tungsten, uranium, and zinc. Coal, petroleum, and natural gas are other minerals to be found there in Wyoming. Wakes of toxic wastes dot and mine tailings the Rocky Mountain landscape. In one major example, eighty years of zinc mining polluted the river and bank near Eagle River in north-central Colorado. A high concentration of the metal carries off by spring runoff.

Agriculture and forestry are two major industries. Agriculture includes arid land and irrigated farming and livestock grazing. This provides you with some of the richest crops throughout the year. Livestock are often moved between high-elevation summer pastures and low-elevation and winter pastures.

Relief maps of the United States partially show why deserts come to exist. The Sierra Nevada and Cascade mountain ranges run along the entire Pacific Coast, acting as a barrier to the humid winds that sweep in from the ocean. The rising topography forces this air upwards, causing moisture to condense and fall in the form of rain on the western slopes of the mountains, with some areas receiving more than convert|70|in|m of rainfall per year. As a result, the air has lost much of its moisture and becomes hot and dry when it reaches the areas east of the coastal mountain ranges. These hot, arid conditions are, in some instances, exacerbated in regions of extremely low altitude (some near or below sea level) by higher air pressure, resulting in drier conditions and adiabatic heating effects. What precipitation does fall generally does not last long, lost primarily to evaporation, as well as rapid runoff and efficient water uptake and storage by native vegetation.

References

* 1.cite encyclopedia
title = Deserts of America
encyclopedia = The Golden Treasury of Knowledge
volume = 4, book 13
pages = 1008-1091
publisher = Fratelli Fabbri
date = 1961
id = 61-10594
accessdate = 2006-08-19

* 2. cite encyclopedia
title = Geography of North America
encyclopedia = Universal World Reference Encyclopedia
volume = 11, book 1
pages = 231-233
publisher = V.S. Thatcher
date = 1964
id = 64-12955
accessdate = 2006-08-19

Notes

ee also

*Central America
*Geographic centers of the United States
*Geography of Canada
*Geography of Mexico
*Geography of Puerto Rico
*Geography of the United States
**Geography of the Eastern United States
**Geography of the Interior United States
**Geography of the Western United States
*Mountain peaks of Canada
*Mountain peaks of México
*Mountain peaks of North America
*Mountain peaks of the Rocky Mountains
*Mountain peaks of the United States
*South America
*Transportation in North America
*The United States

Bibliography

Map and aerial photos
* [http://www.geographicguide.com/north-america-map.htm North America map]
* [http://www.globe-images.com/north-america-image.htm Physical map]
* [http://www.globe-images.com/great-lakes.htm Map of the Great Lakes]
* [http://www.globe-images.net/north-america.htm North American map]
* [http://www.geographicguide.com/north-america-map.htm North America Political map]
* [http://www.infoplease.com/ipa/A0779260.html Oldest Human Remains in North America Found]
* T. H. Clark and C. W. Stearn, "The Geological Evolution of North America" (1968)
* W. P. Cumming et al., "The Discovery of North America" (1972)
* R. C. West et al., "Middle America: Its Lands and Peoples" (3d ed. 1989)
* T. L. McKnight, "Regional Geography of the United States and Canada" (1992)
* S. Birdsall, "Regional Landscapes of the United States and Canada" (4th rev. ed. 1992)
* T. Flannery, "The Eternal Frontier: An Ecological History of North America and Its Peoples" (2001)
* A. Taylor, "American Colonies" (2001).