\ - i -Vt1 t _ 9 \ "» y \R Landforms, C52 Slow Changes on Land, C58 Fast Changes on Land, C68 w -4 Did You Ever Wonder? What forces shaped these rocks? Wind and rain shaped them over thousands of years. If you could visit this park a thousand years in the future, what changes might you see? How is Earth's surface changed over time? C 50
\y f landform, C54 mountain, C55 valley, C55 sand dune, C55 plain, C55 river, C55 _- Process Skill You classify when you place things that share properties together in groups. C52 What is Earth's surface like where you live? Are there mountains or hills? Is the land very flat? Maybe you live where there are lots of lakes or rivers. Maybe you live near a desert. Earth's surface has many different features. How do You think these features are alike? How are the7 different?
Explore Activity. How Do the Features of Earth's Surface Compare? Procedure Q Observe How are the pictures alike? How are they different? Discuss these questions with a partner. El Classify Sort the pictures into two groups. Describe how you sorted them. El Classify Repeat step 2. This time try to sort the pictures into three groups. Drawing Conclusions Q What categories did you sort the pictures into? E3 Infer For each picture, list some living things that could live in the place shown. Going Further: Predict For each picture, predict how the land might change during a year. How might it change after many years? C53
'l Read to Learn ' (» > X Main Idea Earth's surface has many features. What Are the Features of Earth's Surface? A landform (LAND-fawrm) is a feature of Earth's surface. Different bodies of water cover large parts of Earth, too. What is a landform? '^W mtfl^^^^ C54
Earth's Landforms Features of the Earth Mountains (MOUN-tuhnz) are the highest landform. Mountains often have steep sides and pointed tops. Hills are shorter and rounder than mountains. A plateau (pla-toh) is flat land with steep sides. It is higher than the land around it. Mesas (MAY-suhz) are flat-topped hills or mountains. A valley (VAL-ee) is the low land between hills or mountains. Water often rushes down into valleys. A canyon (KAN-yuhn) is a deep, narrow valley with steep sides. Canyons often have rivers at the bottom. Sand dunes (SAND DEWNZ) are mounds of wind-blown sand. Plains (PLAYNZ) are wide, flat lands. Earth's Water Features Rivers (RIV-uhrz) are large streams of water that flow across the land. A lake is a body of water with land all around it. Oceans are very large bodies of salt water. They cover about three-fourths of Earth's surface. The Coast is where the ocean meets the land. Diagrams Which features of Earth's surface are found near you? A bay is a part of a lake or ocean that extends into the land. Glaciers (GLAY-shuhrz) are huge masses of ice that move slowly across the land.
\t,- All of the features you just read about can be found in the United States. The map and pictures show some of these features. READING Cause and Effect Why is much of the food in the United States grown on the Great Plains? Lakes All states have small lakes. The Great Lakes are among Earth's largest lakes. Coast Nearly half of the United States borders an ocean. Mountains The Rocky Mountains run north to south, and they cover much of the west. C56 Plains Ranging between North Dakota and Texas are the Great Plains. Farmers on the Great Plains raise much of the food we eat. Rivers Many rivers flow into the Mississippi River. This river empties into the Gulf of Mexico.
Lesson Review Why It Matters Wherever you live, the land affects you. The land on the Great Plains is good for growing grains like corn and wheat. Coasts and lakes are good places to go fishing. If you live on a mountain, you need to be good at climbing! Some places in the United States are very special. Have you ever visited a national park? National parks are places set aside for people to visit and enjoy. Think and Write 1. What is a landform? Give an example. 2. Describe three different ways that water covers Earth's surface. 3* Why are the Great Plains important? 4. How is a mesa different from a plateau? 5. Critical Thinking Why do crops grow better on plains and on valleys than on mountains? WRITING LINK Write a story. There are many ways to explain how the Grand Canyon was formed. Ancient people used stories to explain how it happened. Create a legend to explain how the Grand Canyon was formed. Draw pictures to help tell your story. MATH LINK Compare numbers. Use the table below. Arrange these states in order of shortest coastline to longest State Alabama Alaska California Delaware Florida Coastline (in miles) 53 5,580 840 28 1,350 SOCIAL STUDIES LINK Write a letter. Explain to another person what the land is like where you live. Discuss how the land affects your life. TECHNOLOGY LINK At the Computer Visit www.mhscience02.com for more links. C57