Latin America: Physical Geography

Transcription

1 Page 1 of 7 Latin America: Physical Geography TERMS & NAMES tributary deforestation Tropical Zone El Niño MAIN IDEA Latin America s landforms, bodies of water, and climate offer a wide range of environments and resources. WHY IT MATTERS NOW Physical geography influences Latin America s cultures, offering them both resources and obstacles. PUEBLA, MEXICO, DECEMBER 19, 2000 Yesterday, Mount Popocatépetl erupted, spewing out glowing five-footlong rocks for miles in one of its largest eruptions in a thousand years. More than 30 million people live within sight of the volcano, and tens of thousands live close enough to be at risk when it erupts. Government trucks drove through villages sounding warnings on speakers while church bells rang out the danger. In spite of the resulting damage, no one has been killed. However, authorities warn, a larger eruption could occur at any time. Place The Aztec named the volcano Popocatépetl, which means smoking mountain. Defining Latin America Latin America includes Mexico, Central America, the Caribbean, and South America. Because the languages of most of its colonizers Spanish and Portuguese are derived from Latin, Europeans later referred to the region s colonies as Latin America. Because the region is defined by a cultural connection, in this case language, it is called a culture region. TAKING NOTES Use your chart to take notes about Latin America. Location Dates Maya Aztec Latin America: Its Land and History 153

2 Page 2 of 7 Mexico Look at the map on page 155. Mexico is the farthest north of the Latin American countries. You can see that Mexico s major physical features include mountains, plateaus, and plains. A Varied Landscape Mexico s two major mountain ranges share the name Sierra Madre (see EHR uh MAH dray). Notice that in between the two ranges the Sierra Madre Occidental and the Sierra Madre Oriental sits Mexico s large central plateau. The vast northern stretches of the central plateau are desert. Now look just south of the central plateau. There you will see Mexico s two highest mountain peaks, Orizaba (or ih ZAH buh) and Popocatépetl (POH puh KAT uh PEHT uhl). Both are volcanoes. Volcanic activity and earthquakes frequently plague Mexico and many other parts of Latin America too. They are caused by the movement of five tectonic plates. occidental: western oriental: eastern A Problem of Place At the southern end of the central plateau sits Mexico City, the world s second most populated city. Air pollution is severe there, and the city s location has contributed to this problem. The mountains surrounding the city to the east, south, and west trap automobile exhaust and other pollutants that the city s huge population generates. An added problem of location for Mexico City is the ground on which it was built a drained lakebed. The vibrations that earthquakes send through Earth grow much stronger and more damaging when they pass through the soft, loose soils of a lakebed, thus making Mexico City highly vulnerable to the effects of earthquakes. Eruption Disruption On February 20, 1943, something very strange happened in a cornfield in west-central Mexico. Before the eyes of a startled farmer, the land violently split open. Within 24 hours, a small, smoking cone had appeared the tiny beginning of a mighty volcano called Paricutín (pah REE koo TEEN). Scientists rushed to the area to watch the volcano being born. Within a year, a mountain stood in place of what had been farmland and a village. While it was active, Paricutín rose to 10,400 feet above sea level. It poured lava over about a 10-square-mile area, burying streets and buildings, such as this nearby church. In 1952, it stopped erupting completely and became dormant. But the volcano that sprouted in a cornfield had given scientists a rare opportunity to study the life cycle of one of nature s most dramatic and dangerous features. 154 CHAPTER 6

3 Page 3 of 7 Physical Features of Mexico, Central America, and the Caribbean N GEOGRAPHY SKILLBUILDER: Interpreting a Map 1. Location What is the tallest mountain in Central America? 2. Region Which area of Mexico is almost entirely at sea level? UNITED STATES of C al OCEAN Central Plateau Gulf of Mexico Gulf Coastal nia ifor re Mad r ra n t a l Sie e Ori e dr Ma l rra Sie denta i Occ G ulf 20 N ATLANTIC Popocatépetl 17,802 ft. (5,426 m.) S ie rra M ad Pl re de l Peninsula ain Belmopan Sur Tacaná 13,428 ft. (4,093 m.) N Tajumulco 13,845 ft. (4,220 m.) Tropic of Cancer Pico Duarte 10,417 ft. (3,175 m.) Pico de Orizaba 18,854 ft. Yucatán (5,747 m.) Mexico City Paricutín 9,210 ft. (2,808 m.) Havana Pico Turquino 6,561 ft. (2,000 m.) Port-au-Prince Tegucigalpa Santo Domingo Caribbean Sea Managua Guatemala City San Salvador San José 10 N Elevation 13,100 ft. (4,000 m) 6,600 ft. (2,000 m) 1,600 ft. (500 m) 650 ft. (200 m) (0 m) 0 ft. Below sea level Chirripó Grande 12,530 ft. Barú (3,819 m.) 11,400 ft. (3,475 m.) Mountain peak 0 Panama City Equator National capital miles 500 kilometers SOUTH AMERICA PACIFIC OCEAN 10 S 110 W 100 W 90 W 80 W 155

4 Page 4 of 7 Place Seven islands make up the Caribbean island group that is called Guadeloupe (GWAHD uhl OOP). Place Coral reefs form in lots of different colors. Central America and the Caribbean Look at the physical map in the Unit Atlas. Central America is the mountainous landmass that forms a bridge between Mexico and South America. Now look to the east, and you will see island nations scattered throughout the Caribbean Sea. Central America About 80 percent of Central America is hilly or mountainous, and most of it is covered with forests. Rain forests cover much of the lowlands. In the higher regions, deciduous trees cloak many of the slopes. A string of more than 40 volcanoes lines 900 miles of Central America s Pacific coast, where two tectonic plates crash against each other. This is the most active group of volcanoes in North or South America. Earthquakes also occur frequently. They can completely destroy buildings, towns, and cities. They can also set landslides and mudslides in motion, sending land, houses, and people hurtling down the slopes. The Caribbean Islands As you can see on the map (page 155), the Caribbean Islands lie to the east of Central America. Some of these islands, such as St. Kitts and Grenada, are actually the peaks of volcanic mountains rising from the ocean floor. Over thousands of years, the volcanoes erupted, spewing lava that cooled, hardened, and added to the mountains height. Other islands, such as the Bahamas, began as coral reefs. Coral is made of organisms that shed hard skeletons when they die. The skeletons pile up, and a reef, or ridge, develops. A coral reef that becomes an island usually encircles a volcanic island and then grows over it. deciduous: a tree that loses its leaves each year A. Clarifying What causes so many volcanoes and earthquakes in this region?

5 Page 5 of 7 isthmus: a narrow strip of land that connects two landmasses The word pampa, meaning flat surface, comes from the language of an Andean group of Native Americans called the Quechua (KEHCH wuh). South America Look at the map on page 142 of the Unit Atlas. You can see that the equator runs through Ecuador, Colombia, and Brazil. You can also see that only the Isthmus of Panama links South America to North America. The Andes On the map, you can see the Andes mountain range, which stretches over 5,000 miles along South America s west coast. It is the longest continuous mountain range on Earth s surface. Mount Aconcagua (AK uhn KAH gwuh) in Argentina is the highest peak in the Western Hemisphere. Beyond the Andes Notice the central plains east of the Andes. The plains in southern South America are called the Pampas. South America s largest rivers begin in the Andes, drain the central plains, and then flow into the Atlantic Ocean. They include the Orinoco (AWR uh NOH koh), the Paraná-Paraguay-Plata (PAR uh NAH-PAR uh gwy-plah tuh), and the Amazon. The Amazon In 2000, 22 people explored the Andes s rivers to confirm the source of the Amazon River, which had been discovered in The mighty river begins in the Peruvian Andes as a trickle of water. It then flows for nearly 4,000 miles to the Atlantic Ocean. No other river carries as much water to the sea. Along with more than 1,000 tributaries, which are rivers or streams that flow into a larger body of water, the Amazon drains water from Peru, Ecuador, Colombia, Bolivia, Venezuela, and Brazil. The Amazon at Risk Deforestation, or the process of cutting and clearing away trees from a forest, has greatly affected the Amazon rain forest. In recent years, Amazon deforestation has provided timber and cleared land for cattle ranches. timber: wood used as building material Place The Andes make a good home for animals like the llama. Latin America: Its Land and History 157

6 Page 6 of 7 Most plants release oxygen into the air and absorb carbon dioxide. By reducing the number of trees and plants, deforestation increases the amount of carbon dioxide in the air. Some scientists think the increase in carbon dioxide contributes to global warming because carbon dioxide traps warm air at Earth s surface. Others worry that animals who find food in the rain forest may need to move or may die out when large areas of forest are cut down. The Native American tribes that inhabit the rain forest are also at risk of being squeezed out of the land they live on. Climate Latin America s climate varies greatly from area to area. It is influenced by elevation, location, wind patterns, and ocean currents. The Tropical Zone A large portion of Latin America lies in the Tropical Zone, which, as you can see on the map below, is between the latitudes 23 27' north and 23 27' south. The Tropical Zone may be rainy or dry, but it is typically hot. Also, temperature is always lower at higher elevations, but in the Tropical Zone, all elevations are warmer than they are elsewhere. Wind and Water The waters in the Caribbean Sea stay warm most of the year and heat the air over them. A warm wind then blows across the islands, keeping the climate warm even in the winter. B. Drawing Conclusions What aspect of the Tropical Zone s location on Earth causes it to be warmer than the other areas? 'N 500 1,000 miles ,000 kilometers N 158 CHAPTER 6 MEXICO PACIFIC OCEAN GUATEMALA EL SALVADOR Equator COSTA RICA PANAMA Tropic of Capricorn The Tropical Zone CUBA BELIZE HONDURAS JAMAICA NICARAGUA ECUADOR HAITI 23 27'S Caribbean Sea COLOMBIA PERU CHILE DOMINICAN REPUBLIC VENEZUELA BOLIVIA PARAGUAY Tropic of Cancer Puerto Rico (U.S.) BRAZIL 23 27'N ATLANTIC OCEAN GUYANA SURINAME French Guiana (Fr.) 23 27'S 20 N GEOGRAPHY 10 N SKILLBUILDER: Interpreting a Map 1. Region Which 0 South American countries are in the Tropical Zone? 2. Location Where 10 S does the equator fall within the Tropical Zone? 20 S

7 Page 7 of 7 Normal Year El Niño Year Westerly trade winds Warm surface water Westerly trade winds die out Warm surface water, warm air, and storms SKILLBUILDER: Interpreting a Diagram 1. What effect does the increased air pressure of El Niño have on the warm surface water of the Pacific? 2. What are the patterns of wind and water in a normal year? El Niño At times, unusually high air pressure in the south Pacific causes certain winds over the ocean, called trade winds, to die out. Without the trade winds, the ocean s sun-warmed surface water flows eastward, toward North and South America. Because this typically occurs around Christmastime, people call the current El Niño (ehl NEE nyaw). This term is Spanish for the Christ child because Christmas celebrates the birth of Jesus. The warmer water of El Niño warms the air. Warmer air holds more water and so releases more rain when it cools.this added precipitation often causes heavy rains and flooding in Latin America and other parts of the eastern Pacific. At the same time, areas in the western Pacific, such as Indonesia, may have less rain than usual. SECTION ASSESSMENT Terms & Names 1. Explain the significance of: (a) tributary (b) deforestation (c) Tropical Zone (d) El Niño Using Graphics 2. Use a chart like the one below to list the key physical features of each country or region. Main Ideas Key Physical Features Mexico Central America The Caribbean South America Islands 3. (a) Name two types of natural disasters that occur frequently in Latin America. (b) Describe two ways in which the Caribbean Islands formed. (c) What happens when increased air pressure causes trade winds to lessen? Critical Thinking 4. Forming and Supporting Opinions Do you favor limiting the deforestation of the Amazon rain forest? Why? Why not? Think About the economic benefits of timber production and cattle ranching the destruction of habitats the effects on the global environment Look at the map on page 158 that shows the Tropical Zone. Make a list of all the Latin American countries that are wholly or partly in the Tropical Zone. Latin America: Its Land and History 159