Transcript Unit 1: North America

Unit 1: North America
Mr. Couvillion & Ms. Dyer
Where is North America?
• North America stretches from
the cold arctic of northern
Canada to the warm tropics of
Mexico. At the center lies the
48 contiguous United States,
which means they are all
connected in one block.
Hawaii the 49th state is in the
Pacific ocean, and Alaska the
50th state lies off the coast of
Canada.
Highlands, Plains, & Plateaus
• Land Elevation in North America
generally rises from East to West,
though the east has some
highlands, or areas of hills and
mountains. East of the rocky
mountains lie the Great Plains.
Plains are flat areas of land, which
make up most of the center of
North America. Plains also appear
near coasts. Plateaus – Flat lands
of high elevation – are located
between mountains in the west
U.S. and central Mexico.
Rivers and Lakes
• Major cities developed along the region’s
numerous rivers, such as Cincinnati and
the Ohio River, New Orleans on the
Mississippi River, and Juarez on the Rio
Grande. The St. Lawrence River provides
a waterway from the Atlantic Ocean to
the Great Lakes. Combined, these 5
lakes form the largest body of fresh
water in the world. Four of the lakes
provide a physical boundary between
the United States and Canada, just as
the Rio Grande is a natural border
between the United States and Mexico.
The Great Plains
• The Great Plains region runs
through the center of the
continent. The crops grown
there feed the population of
North America with enough
left to export, or send to
other countries for aid or
profit.
Farming on the Great Plains
• The Great Plains are well suited to agriculture for two reasons. First, the soil is rich with nutrients,
so it produces bountiful crops. Second, the climate on the Great Plains is temperate and the area
usually has a plentiful amount of rain.
• Some years, rainfall is below normal for a long period of time, causing drought that can kill crops.
In the 1930’s, for example, the region experienced a drought that lasted several years. Plowing of
native prairie grasses that helped hold the soil contributed to soil erosion, and the Plains became
known as the “Dust Bowl.” The persistent winds in the area stirred up great clouds of dry soil, or
dust. Today these winds can be a source of power.
• Much of the original prairie land has been replaced by fields of wheat, corn, and other grains.
These crops are grown on huge farms where planting and harvesting are done by machine. Such
large, highly productive farms are typical of commercial agriculture, or the business of producing
crops to sell.
• Rivers such as the Mississippi transport goods from the Great Plains to lowland areas. Grain from
the Canadian plains is moved by rail to the Atlantic Ocean and by ship on the Great Lakes and St.
Lawrence River.
Energy Resources
• The Great Plains in the United States and Canada are
home to major deposits of oil and natural gas. The main
oil fields in the United States are found in the southern
part of the Great Plains, from Kansas to Texas. Texas
also has many offshore oil fields in the Gulf of Mexico.
• Commercial drilling in the Gulf of Mexico is risky. Oil
deposits lie beneath the layers of salt that can shift and
cause an underwater earthquake. In 2010, human error
causes an explosion of a large deepwater drilling
structure, resulting in a major oil spill. The spill harmed
wildlife and threatened the economy of the region.
• Energy resources from the Great Plains are important to
the United States, where more energy is used than it is
produced. High winds in the plains may be utilized as an
alternative energy source.
Western Mountains and Deserts
• Mountains and high
plateaus cover much of
the western United State
and Canada. These
landforms create natural
barriers to western
coastal regions and offer
plentiful resources in
some areas.
Landforms and Climate
• The main landform in the western part of the region is the cordillera. A cordillera is a
system of several mountain ranges that often run parallel to one another. In North
America, the Cordillera includes the Rocky Mountains and the Sierra Nevadas.
• In the United States, the area between the Rocky Mountains and Sierra Nevada
Mountains is the Great Basin. A basin is a depression in the surface of the land. The
Great Basin is a desert, a dry, often sandy area with little rainfall or plant life.
• The Great Basin is marked by smaller mountain ranges and canyons, which are deep,
steep-sided valleys formed when rivers cut through soft rock. The best known canyon
is the Grand Canyon in the southwestern United States. Formed over hundreds of
millions of years, it is 277 miles in length and up to 18 miles wide.
• The great basin is mostly dry. Warm, moist air flows east from the Pacific Ocean
toward the mountains of the cordillera. As this warm air rises up the mountains, it
cools and releases moisture on the mountains’ western slopes. The air that eventually
reaches the land east of the mountains is dry. This process is called the Rain Shadow
Effect.
Resources and Conservation
• Varying climates contribute to a varied supply of resources.
The great basin and the mountain ranges that surround it
contain important mineral deposits. Areas of southwestern
Canada hold reserved of natural gas. This area’s heavy rainfall
and many lakes allow for the use of water power to provide
electricity.
• Water for human use is in short supply in the southwestern
United States. The population there has grown rapidly in
recent years, and the demand for water has increased in an
already dry area. A dam, which is a barrier that controls the
flow of water, can help solve the problem of water shortage.
However, dams can also cause problems such as excess soil
erosion. The Hoover Dam on the Colorado River makes use of
water power to supply electricity, irrigation, and drinking
water to parts of Arizona, New Mexico, and southern
California.
Mexico’s Mountains and Plateaus
• Central Mexico is
made up mainly of
mountains and
plateaus. These
landforms yield
rich resources that
contribute to
Mexico’s economy
Landforms & Climates
• Mexico includes two peninsulas, narrow strips of land that extend out into a body of water: The
Baja in western Mexico and the Yucatán in the southeast. Mexico is shaped like an upside down
triangle with the mountains of the Sierra Madre running along each side. The Mexican Plateau lies
between the two ranges of the Sierra Madres. Mexicans call the southern area of this plateau the
Mesa Central, and the northern area the Mesa del Norte. A mesa – the Spanish word for “table” – is
a high flat plateau. Mexico’s highest mountain, volcano Pico de Orizaba, rises at the southern edge
of the plateau.
• Mexico City, the capital, is on the Mesa Central. The city is home to more than 20 million people,
almost 20% of the population of Mexico. Some areas of the Mesa Central have been subject to
volcanic activity, which results in rich, volcanic soil. This soil helps produce crops that are
important to Mexico’s economy such as sugarcane, corn, and wheat.
• Northern Mexico sits in the temperate zone, and the southern half lies in the tropics. On the high
Mesa Central, climate is modified, or made less extreme, by a higher elevation. Temperatures
there are cooler than along lower coastal areas.
Resources and Agriculture
• Mexico’s mountains hold resources such as
copper, silver, and zinc. However, the richest
resource is the oil found in and around the
Gulf of Mexico. Over three million barrels are
produced each day.
• Agriculture is also important to the country.
Farmers in the north grow cotton, wheat,
and fruit, and also raise cattle. To the south,
farms produce sugarcane, coffee, and
tropical fruits. Many rural Mexicans live by
subsistence farming, growing just enough
food to feed their families. This type of
farming occurs mostly in southern highlands.