• Unit 5: Middle and South America

    Middle America is the geographic realm between the United States and South America. It consists of three main regions: the Caribbean, Mexico, and Central America. The Caribbean, the most culturally diverse of the three regions, includes more than 7,000 islands that stretch from the Bahamas to Barbados. The four largest islands of the Caribbean are the Greater Antilles: Cuba, Jamaica, Hispaniola, and Puerto Rico. Hispaniola is comprised of two halves: Haiti in the west and the Dominican Republic in the east. The smaller islands, extending all the way to South America, make up the Lesser Antilles. Trinidad is the farthest south, just off the coast of Venezuela. The Bahamas are closest to the mainland United States.

    Central America refers to the seven states south of Mexico: Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, and Panama. The Pacific Ocean borders Central America to the west, while the Caribbean Sea is on the east coast. Most of these countries straddle the Caribbean Sea and the Pacific Ocean. However, Belize only has a shoreline on the Caribbean, and El Salvador is only on the Pacific.

    The continent of South America has diverse physical landscapes, from the Andes mountains to the tropical forests of the Amazon basin. Venezuela and Columbia have abundant precious metals and fossil fuels, while the Amazon basin is a source of lumber and, more recently, some of the largest iron-ore mines in the world. The massive plains of Brazil and the rich soils of the Pampas allow for enormous agricultural operations. Even the inhospitable Atacama region in northern Chile holds some of the world's largest copper reserves. The wide variety of climate zones allows for a diverse ecosystem, and the extremes of physical geography have created both barriers and opportunities for those who live there.

    In this Unit, we investigate the physical characteristics of Middle and South America. Then, we will explore the human landscape before colonization, including the Mayan, Aztec, and Incan Empires. We identify the effects of European colonialism, especially how Spanish colonizers influenced patterns of land-holding and urban development. This region is highly urbanized, so we learn about the phenomena of primate cities and megacities. Finally, we return to the themes of inequality and globalization within the context of Middle and South America.

    Completing this unit should take you approximately 5 hours.

    • 5.1: Maps of Middle and South America

      We begin our examination of Middle and South America by studying some maps of the region.

    • 5.2: The Physical Geography of Middle America and South America

      North, Middle, and South America would comprise a continuous landmass were it not for the Panama Canal, a human-made break in the Isthmus of Panama. Although the physical connection between Central America and South America appears fragile on a map, the cultural connection is strong.

      The physical landscape of Middle and South America is varied, ranging from volcanic islands to mountain ranges to tropical rainforests and deserts. It also includes agricultural regions such as the Pampas region of South America, prairie grasslands like Argentina's Patagonia, and the cenotes or sinkholes of the Yucatán peninsula. This region's rivers are some of the largest in the world by discharge volume. They include the Amazon, Orinoco, Rio Negro, and Madeira Rivers.

      The climate of this region varies considerably. For example, we often associate South America with the tropical Amazon Rainforest. However, most of the continent does not straddle the Equator. Because the South American continent extends from 12° N to 54°S, its climate varies and includes tropical, temperate, arid, cold, and polar climates. Furthermore, the local topography means there are variations within those climate types.

      Given the vast expanse of Middle and South America, it is not surprising that the physical geography of the region is varied. Here are some features.

      Atacama Desert


      Altitudinal Zonation:

      – Tierra Caliente

      – Tierra Templada

      – Tierra Fria

      – Tierra Helada

      – Tierra Nevada

      Amazon Basin, Amazon River, Amazon Forest


      The Caribbean Sea

      El Niño- Southern Oscillation (ENSO)

      Isthmus of Panama

      Panama Canal

      Lake Nicaragua

      Greater Antilles:

      – Cayman Islands

      – Cuba

      – Jamaica

      – Hispaniola (Haiti, Dominican Republic)

      – Puerto Rico

      The Lesser Antilles:

      – The Bahamas

      – Leeward and Windward Islands

      – Leeward Antilles

      Mountain Ranges:

      – Andes Mountains

      – Sierra Madre Occidental

      – Sierra Madre Oriental

      – Sierra Madre del Sur



      – Atlantic Ocean (North Atlantic)

      – Pacific Ocean (East Pacific)

      Tectonic Activity:

      – Earthquakes

      – Volcanoes

      Tectonic Plates:

      – Caribbean

      – Cocos

      – Nazca

      – North American

      – South American

      Tropical Storms:

      – Hurricane

    • 5.3: The Panama Canal

      The Panama Canal is a critical connection between the Atlantic and the Pacific Oceans. While its initial construction was deadly, the canal saves ships from having to travel around the southernmost tip of South America, Cape Horn, through the Drake Passage or the Strait of Magellan, or north through the Arctic Archipelago and the Bering Strait.

    • 5.4: Amazon River Basin

      Although many people associate the Amazon River Basin with Brazil, its area covers more than a third of South America, including Peru and Ecuador to the west, Bolivia to the south, and Colombia, Venezuela, Guyana, and Suriname to the north.

    • 5.5. The Atacama Desert

      The Atacama Desert (shown in yellow in Figure 5.5) is west of the Andes, primarily in northern Chile. Some of the outlying arid regions (shown in orange in Figure 5.5) extend into Peru and Bolivia. No rain has fallen in some parts of the Atacama in recorded history, making this area the driest place on Earth outside Antarctica. Because there are mineral resources in the desert, including copper and nitrates, there is some human activity there. Indeed, mining in the Atacama has proven to be quite lucrative.

    • 5.6: Earthquake and Volcano Hazards

      Like the west coast of North America, the west coasts of Middle America and South America coincide with active plate boundaries. The west coast of this region is tectonically active.

    • 5.7: Hurricane Hazards

      In addition to earthquakes and volcanoes, Middle America and northern South America are also prone to hurricanes, which are common in North America and other locations around the world (see Figure 5.13).

      Note that hurricanes, cyclones, and typhoons are all types of tropical storms. The different names refer to their location: hurricanes form over the North Atlantic and Northeast Pacific Ocean, cyclones form over the South Pacific and the Indian Ocean, and typhoons form over the Northwest Pacific Ocean. Thus, the tropical storms that strike China are typhoons, those in Mexico are hurricanes, and those in Madagascar are cyclones.

    • 5.8: The Colonization of Middle America

      Middle America is one of the world's ancient cultural hearths due to the contributions of the Maya and Aztec civilizations. As in North America, the European colonists profoundly affected the indigenous populations. While the rimland was accessible to European ships, the mainland's interior remained more isolated. These locations determined the style of agriculture, type of crops, and labor sources.

    • 5.9: The Colonization of South America

      Spain and Portugal colonized all of South America except for the Guianas (Guyana, Suriname, and French Guiana). Spain focused on South America's west coast, which borders present-day Colombia, because they had already colonized Middle America.

    • 5.10: Urban Development in Middle and South America

      In Tenochtitlán, the capital city of the Aztec empire, temples, palaces, and public buildings dominated the city center while economic activities occurred on the periphery. The commoners in Aztec society lived on the urban periphery because many were engaged in agriculture.

      When the Spanish colonized Middle and South America, their model left members of the working class on the periphery but placed economic activities in the city centers.

      Here are some common elements of this model which still exist in many Middle and South American cities.

      • The marketplace or plaza is the city center.
      • Churches, government buildings, residences for the wealthy, and permanent stores define the boundaries of the plaza.
      • This plaza and the immediate perimeter that surrounds it constitute the city's core.
      • The income of each residential zone decreases according to its distance from the core.
      • Cities grow by adding concentric rings – fewer city services exist with each additional ring.
      • The poorest city residents live in barrios or favelas in the outermost ring, where there are no city services.
    • 5.11: Income Inequality in Middle and South America

      This section presents the recurring theme of income inequality in Middle and South America. Figure 4.13 from Unit 4 shows that Middle and South American countries share a high Gini coefficient with the United States. In some countries, such as Brazil, Colombia, Mexico, and Barbados, it is even higher.

    • 5.12: Patterns of Globalization in Middle and South America

      Middle America is well-connected to the region of North America. In July 2020, Mexico joined the United States, Mexico, Canada Agreement (USMCA), the successor to the North American Free Trade Agreement (NAFTA). USMCA is a free trade agreement among the three countries. It facilitates increased cross-border trade and addresses agricultural produce, manufactured products, labor conditions, digital trade, and other provisions.

      Without question, the United States is Mexico's biggest trading partner. Canada is a distant second. Roughly 78 percent of Mexico's exports go to the United States, while only three percent go to Canada. USMCA is positive from Mexico's perspective, although the treaty requires Mexico to meet certain labor standards, such as a minimum wage requirement in the automotive industry. These labor provisions will marginally improve income inequality in Mexico. However, some are concerned the increased labor costs in the USMCA-related segment of Mexico's economy will impede aggregate productivity.

    • Unit 5 Assessment

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