1. Topography - Exploring Earth’s Surface
The route of the Lewis and Clark expedition crossed regions that differed greatly in elevation, relief, and landforms.

2. Types of Landforms - Exploring Earth’s Surface
There are three main types of landforms: plains, mountains, and plateaus.

3. Types of Landforms - Exploring Earth’s Surface
A large area of land where the topography is made up of mainly one type of landform is called a landform region.

4. Comparing and Contrasting
- Exploring Earth’s Surface
Comparing and Contrasting
As you read, compare and contrast the characteristics of landforms by completing a table like the one below.
Characteristics of Landforms
Landform
Elevation
Relief
Plain
Low
Low
Mountain
High
High
Plateau
High
Low

5. Maps and Globes - Models of Earth
Maps and globes are drawn to scale and use symbols to represent topography and other features on Earth’s surface.

6. An Earth Reference System
- Models of Earth
An Earth Reference System
Distances around circles are measured in degrees.

7. An Earth Reference System
- Models of Earth
An Earth Reference System
The equator and prime meridian divide Earth’s surface into hemispheres.

8. Locating Points on Earth’s Surface
- Models of Earth
Locating Points on Earth’s Surface
The lines of latitude and longitude form a grid that can be used to find locations anywhere on Earth.

9. Locating Points on Earth’s Surface
- Models of Earth
Locating Points on Earth’s Surface
Every point on Earth’s surface has a particular latitude and longitude.

10. Map Projections - Models of Earth
A Mercator projection is based on a cylinder with grid lines that has been flattened. On a Mercator projection, lines of longitude are parallel, so shapes near the poles are distorted.

11. Map Projections - Models of Earth
An equal-area projection shows areas correctly, but distorts some shapes around its edges.

12. Map Projections - Models of Earth
A conic projection is based on a cone that covers part of Earth and is then rolled out flat. A conic projection’s grid is formed from straight lines of longitude and curved lines of latitude.

13. Asking Questions - Models of Earth
Before you read, preview the red headings. In a graphic organizer like the one below, ask a question for each heading. As you read, write answers to your questions.
Question
Answer
What is meant by an Earth reference system?
Just like a checkerboard, a grid system is needed to locate points on Earth.
How do you locate points on Earth’s surface?
Lines of latitude and longitude can be used to locate any place.
Why are there different types of map projections?
Different types are useful for different purposes.

14. Latitude and Longitude
- Models of Earth
Latitude and Longitude
Click the Video button to watch a movie about latitude and longitude.

15. Identifying Main Ideas
- Maps and Computers
Identifying Main Ideas
As you read the section “Maps and Computers,” write the main idea in a graphic organizer like the one below. Then write three supporting details that further explain the main idea.
Main Idea
Computers use digitized data to make maps.
Detail
Detail
Detail
Digitizing is converting the location of map points to numbers.
Much of the data is gathered by satellites.
The Global Positioning System (GPS) is used to find latitude, longitude, and elevation.

16. Mapping Earth’s Topography
- Topographic Maps
Mapping Earth’s Topography
Mapmakers use contour lines to represent elevation, relief, and slope on topographic maps.

17. Reading a Topographic Map
- Topographic Maps
Reading a Topographic Map
To read a topographic map, you must familiarize yourself with the map’s scale and symbols and interpret the map’s contour lines.

18. Mapping Elevation Data
- Topographic Maps
Mapping Elevation Data
The map shows the elevation data points on which the contour lines are based. Study the map and the map key, then answer the questions.

19. Mapping Elevation Data
- Topographic Maps
Mapping Elevation Data
Reading Maps:
What is the contour interval on this map?
100 feet

20. Mapping Elevation Data
- Topographic Maps
Mapping Elevation Data
Reading Maps:
What color are the lowest points on the map? What range of elevations do these points represent?
Yellow; points below 1,200 feet.

21. Using Prior Knowledge - Topographic Maps
Before you read, write what you know about topographic maps in a graphic organizer like the one below. As you read, write what you learn.
What You Know
Some maps show where mountains and plains are.
Many people use maps to plan a trip or hike in unfamiliar areas.
What You Learned
Mapmakers use contour lines to represent elevation, relief, and slope on topographic maps
A map’s scale and symbols can help you to interpret the map’s contour lines.
Topographic maps have many uses in science and engineering, business, government, and everyday life.

22. Graphic Organizer Landforms Mountains Plains Plateaus Coastal Interior
include
with
which may be
Landforms
Mountains
Plains
Plateaus
High elevation, high relief
High elevation, low relief
Coastal
Interior
Low to high elevation, low relief
Low elevation, low relief