Pre AP Social Studies

Physical Geography

Middle and South America

Physical Geography of Middle America

Middle America is a term that geographers use to describe the region between Mexico and Panama. This region is divided into 3 distinct areas Mexico, Central America (the counties from Guatemala to Panama) and the CaribbeanIslands. Although Middle America is part of the North American continent we study this region with South America because culturally it is more like South America. Middle and South America together are called Latin America. The term “Latin” refers to Spanish and Portuguese languages that are spoken in South and Middle America, which grew out of the Latin spoken in ancient Rome. Most Latin Americans are Roman Catholic.

Landforms

Mountains

The mountains of Middle America form a Y. On the eastern side of the Y are the Sierra Madre East (also known as the Sierra Madre Oriental-oriental means east), on the western side of the Y are the Sierra Madre West (also known as the Sierra Madre Occidental-occidental means west), and the bottom part of the Y are the Sierra Madre South (or the Sierra Madre del Sur-del Sur means of the south).

Plateaus

In the middle of the Y is a large plateau or mesa-“table” in Spanish. The Plateau of Mexico (or Central Plateau) is the central mesa between the Sierra Madre ranges.

Plains

The plains of Middle America are coastal plains along the Pacific Ocean, Gulf of Mexico and the Caribbean Sea. The only plain area that is not a coastal plain is the YucatanPeninsula.

Isthmus

An isthmus is a narrow neck of land that acts as a bridge to connect two larger bodies of land. The Isthmus of Panama links North and South America.

CaribbeanIslands

TheCaribbeanIslands are divided into three regions. TheBahamanIslandsare located just east of Florida. They are cays (keez),whichare low-lying coral islands formed over thousands of years from the accumulation of the rock skeletons of tiny sea animals. The Greater Antilles are the four largest islands—Cuba, Jamaica, Hispaniola, and Puerto Rico and were formed by active and inactive volcanoes. The Lesser Antilles are an arc of many islands from the Virgin Islands to Aruba—they were also formed by volcanoes. All the Caribbean islands collectively are known as the West Indies.

Lakes and Rivers

Lakes dot the landscape the largest is Lake Nicaragua. Most rivers in Middle America are shallow and therefore not navigable.

Climates and Vegetation

Desert and Steppe

These dry climates are found in northern Mexico because the Sierra Madres block rain from getting to the interior plateau. The vegetation is desert scrub.

Highland regions

Highland regions are located in the middle of Mexico on the central plateau and Central America. Coniferous and Mixed forest grow in this region. Elevation is a key climate variable throughout much of Mexico.

Tropical Wet

Tropical Wet climates are located along the east coast of Central America; Tropical Rainforest grows here.

Tropical Wet and Dry

This climate is found along the west coast of Central America and southern Mexico, most of the Yucatan Peninsula, Cuba, and Hispaniola. Savanna vegetation, which consists of tall grasses and scattered trees, grows in this region.

Physical Geography of South America

Landforms

Mountains

The Andes (Spanish word for terrace) run north to south 4,500 miles along western South America. They are the world’s longest unbroken mountain range that formed when a continental and oceanic plate collided. These mountains are still building and as a result the region has many devastating earthquakes and volcanoes. Some of the peaks of the Andes are as high as 20,000 ft.—only the Himalayas are higher. Another region of mountains or highlands in South America is the Guiana Highlands. These highlands run from Venezuela to Suriname; they are oldand worn down (similar to the Appalachians). The highest waterfall in the world, AngelFalls is found here. AngelFalls bursts out of caves below the cliffs edge to plunge 3,200 ft. to the ground. The Brazilian Highlands cover most of southern Brazil and are also similar to the Appalachian Mountains in that they are old and worn—they only rise up to 5,000 ft.

Plateau

A large plateau, Patagonia, covers the southern most region of South America in Argentina. Patagonia is dry and wind swept with deep canyons formed by rivers.

Plains

South America has large plains areas that are very important for agriculture. The Llanos found in Venezuela and Colombia is a wetter plains region compared to the Gran Chaco and Pampas, located mostly in Argentina. The AmazonBasin is a plains region almost as large as the contiguous United States. This basin drains the Amazon River, which flows from the Andes east to the Atlantic. The Amazon is the 2nd longest river (the Nile is 1st) in the world but carries more water. Another plain is the Atacama Desert, which runs from 5oS to 30oS along the west coast of South America.

Climates and Vegetation Regions: South America has a variety of climates from one of the wettest regions in the world, the tropical rainforests of the Amazon, to one of the driest regions in the world, the AtacomaDesert.

Tropical Wet

In South America the tropical wet climate is found along the equator except in the Andes. The vegetation is Tropical Rainforest. In fact South America’s rainforest is the world’s largest. This rainforest has the most varied mass of vegetation found anywhere on earth with 1000s of species of plants and animals found mostly in the canopy: the uppermost spreading branch layer of a forest. In a tropical climate it rains almost everyday and with the average temperature around 82o.

Tropical Wet and Dry

Tropical grasslands like the Llanos grow in the tropical wet and dry climate. This climate has a rainy season that lasts about six months and a dry season for the remainder of the year. The average temperature is also around 82o.

Highlands

The highland climates of South America are found in the Andes where temperature and vegetation growth varies with elevation. Closest to sea level is the tierra caliente, or hot land. In these regions, tropical crops such as bananas and sugar cane flourish. Higher in the mountainsis the tierra templada or temperate zone. Coffee and tobacco grow at this altitude. The third zone is the tierra fria, or cold land. This region includes highlands that are at least 6,000 feet above sea level. Farmers who live here cultivate wheat, barley and potatoes. Above the tierra fria the Andes are snowcapped all year long.

Steppe

The Pampas and Gran Chaco are steppe climates with temperate grasslands, which are drier than tropical grassland but are good for farming.

Desert

The Atacama Desert is one of the driest places on earth. Some areas of the Atacama have gone 20 years without rain. The extreme dryness of the Atacama is due in part to the “rain shadow” created by the Andes. Winds blow from the Atlantic across South America, dropping their moisture as they reach the Andes. As a result the eastern slopes of the Andes—the AmazonBasin—receives drenching rains while the western side remains very dry. Another factor impacting the Atacama is ocean currents. The Humboldt Current is a cold-water current that runs up the west coast of South Americapreventing rain along the western coast. The Atacama is rich in minerals. Patagonia is dry with desert scrub vegetation.