The atmosphere, hydrosphere and lithosphere function collectively to provide he environment which sustains the biosphere. These four spheres interact to create ecological systems. These ecosystems, as they are called, are groups of organisms and the nonliving environment which they exist in. In the process of living and working in an area, people modify the landscape to suit their purposes or tastes. These are called cultural landscapes. Many geographers maintain that the entire surface of the earth constitutes a cultural landscape, as humans have changed the face of the planet to such a great degree. Some geographers also put forth environmentalist theories, which emphasize the role of the environment in human life. The interaction between humans and the environment is a circular effect- environment affects human life and culture, while humans alter and transform the environment. Geographers have studied the ways that societies adapt to the environment- this is known as cultural ecology. Environmental determinism is the simplistic belief that human events can be explained entirely as the results of the effects of the physical environment. While these theories are considered interesting, there are always exceptions to be found. A more moderate view promulgated by geographers is possibilism. Possibilism insists that the physical environment itself will neither suggest nor determine what activity people will undertake, but it will limit what people can profitably achieve.

Part 2: A Geographic Comparison of North and South America

In this section we will apply the fundamentals discussed previously to the respective geographies of North America and South America. This will highlight the similarities and differences between the two continents, and provide examples of how and why geographers study the topics particular to the field.

Location can be discussed in an absolute sense or a relative one. To describe either area in absolute location, we must refer to the geographic grid. The recognized demarcation between the two landmasses is the small isthmus nation of Panama. North America extends from just above the equator to the North Pole. In the east-west direction, North America spans from approximately 10 degrees W. (northeastern tip of Greenland) to 170 degrees W. (western tip of Alaska). The northernmost part of North America is also Greenland, which extends well past the 80 degree N. latitude. The southernmost section is Panama, at approximately 8 degrees N. latitude. South America has its northernmost point in Venezuela, at approximately 12 degrees N. latitude. South America traverses the equator, and it southernmost region is the small group of islands of Chile, which end at 56 degrees S. latitude. The easternmost point of South America is in Brazil, at 35 degrees W. longitude, while the wetsernmost point is the west coast of Peru, at 81 degrees W. longitude.

Location can also be portrayed relatively as well. South America lies to the south and slightly east of North America, and conversely, North America can be said to be to the north and slightly west of South America. Similar statmenets can be made about either continent in relation to the other continents of the world- both Americas are west of Europe, but east of Asia, for instance. As can be seen from the example, relative location depends upon where you are at the moment and the location you wish to compare to.

For purposes of geographic study, we divide the world into regions, which are areas defined by one or more distinctive characteristics or features. Area analysis is a method of organizing the study of the world's people and environments through identification of regions and descriptions of the similarities and differences among them. Probably the most familiar of all maps of regions is the political map.

Map 1

In the preceding map, we see the political demarcations of North America. The main countries of this region are the United States, Canada, and Mexico. In addition, we can see the country of Greenland in the northern Atlantic Ocean. Within the North American Region, there are two prominent subregions- Central America and the Caribbean. Central America, along with Mexico, provide us with an example of a region based upon cultural considerations,...

The Caribbeans are a collection of islands situated off the southeastern portion of the United States.
Map 2

In Map 2 (above), we can see the political boundaries of South America. Brazil is by far the largest country in land area. Only two of the countries in the continent are land-locked, Paraguay and Bolivia. Every other nation has long stretches of coastline. While North America is largely a temperate climate, the vast majority of South American lands fall within the tropical zone (as shown by the position of the Tropic of Capricorn).

Other than examining the political boundaries inherent to each continent, we can use maps to describe the topography, or terrain, of the region. Most topographical maps are color coded according to altitude, with browns representing the highlands and mountains and greens representing the lowlands and plains.

Map 3

In Map 3, we can see the topographic features of North America. The high altitudes are shown in red, and the low altitudes in green, with yellow being an intermediary color. The large red area on the west coast of the continent shows the layout of the Rocky Mountains, while the small red area close to the eastern seaboard gives us an impression of the Appalachians. We can see from the map that Greenland is at a relatively high altitude. The coasts are in green, signifying that they are very close to sea level.

Map 4

Map 4 provides us with a similar viewpoint of South America. As with the previous maps, the high altitudes are signified by red, while the lowlands are green. The color scheme clearly shows that the highest altitudes in South America are the Andes Mountains to the west. Brazil has large stretches of relatively high altitude territory as well.

Maps also exist that provide information of both types. These maps outline geopolitical boundaries as well as naming specific topological regions.

Map 5

Here, we can see the national and international borders represented in red. The topographical elements of the map rely on shades of green to imply altitude. The Rocky Mountains and the Appalachians are clearly marked. In addition, we see the region named the Coastal Plains, another example of a region identified with a common terrain and climate.

Map 6

From this map we can gain a new perspective of the Andes. The mountain range provides a natural boundary between the countires of Chile and Argentina in the southern portion of the range, as well as the respective boundaries between Peru and Bolivvia in the central area. Also, we can see the Brazilian Highlands as the high altitude area from the topographical map. The Amazon Basin is another example of a region which has been classified because of a common unifying feature, in this case the Amazon River. To the north of the basin is another area that geographers have delineated as its own region in and of itself, the Guiana Highlands.

Maps are also used by Geographers to study the human population.

Map 7

Map 7 shows us the population density of North AMerica. As shown by the scale, the darker hues represent areas of higher population density. The highest concentration of people in the United States is in the area of New York, on the east coast. Overall, the eastern half of the continental U.S. has a much higher density than the western half. The population density does not rise significantly until the west coast is imminent.

However, when compared to Mexico, it can be seen that the overall population density of the U.S. is lower than the southern regions (including the Caribbean).

Map 8

South America shows the greatest concentration of people near the coasts, which is common. Many people rely on the oceans to support them, through fishing or trade. The area west of the Andes Mountains has a great concentration of individuals, especially in the tropical regions. The coast of Brazil boasts a large number of people, as the coasts represent the center of urbanization for the country. The Amazon Basin, by contrast, has the lowest population density of the entire continent, even at the mouth of the river. This fact is significant, for it is common for civilizations to center around the mouths of rivers, such as in China and India. The Amazon River seems to lack any serious concentrations of people that would normally accompany such terrain. The Mississippi River in North America, by comparison, is home to historical port of New Orleans.

Map 9 is another example of a map that combines several features. It has marked international boundaries. It shows the location of cities, which are centers of population. It also shows topographical features and regions, which are named as well. Maps of this variety allow geographers to study the relation of human population with the surrounding environments. For instance, most cities are located where they are for accessibility reasons- the city's inhabitants need access to the outside world for resources. An example of this sort of…