Earth's Varied Topography
Name ___________________________________________ Pd ____
Slide 1: The physical features of Earth vary from place to place. In some places, the land is relatively flat. In other places, tall
mountain ranges dominate the landscape. The shape of Earth's surface is its topography.
1. Write a detailed description of the topography that you encounter during this flyby.
Slide 2: A 3-D flyby is one way to see Earth’s shape, but being able to read the information from a flat map is much more convenient.
A special kind of map, called a topographic map, uses contour lines to represent the shape of surface features.
2. Compare the photo to the topographic map. Describe the pattern of the contour lines around features on the
photo.
Slide 3: The image on the left is a topographic map. Maps like these are also called contour maps after the contour lines that trace
out areas of equal elevation. On the right, an oblique view shows a 3-D model of the same area. As the surface of water always
remains flat, simulating a flood of this area can show how contour lines trace out equal elevations.
3. Which part of this land is the last to flood as the water rises?
Slide 4: The elevation of land is its height above sea level. The numbers written on contour lines indicate the elevation of the lines.
Topographic maps would be very cluttered if all contour lines were labeled, so only the heavier lines show labels. The elevation of
unlabeled contour lines can be determined using the contour interval at the bottom of the map. The contour interval tells the
vertical distance between neighboring lines. By counting the number of contours from a labeled line, and multiplying by the contour
interval, you can calculate the elevation of any contour line. For points located between contour lines, you can estimate the
elevation by examining the distance to the two closest contours.
4. What is the elevation of the points marked A, B, and C?
Slide 5: This page shows a topographic map and a three-dimensional model of the same area.
5. Describe the overall shape of the landscape.
6. What do closely spaced contour lines indicate about the shape of a feature? In other words, when the lines are
close together, does the feature have gentle slopes or steep sides?
Slide 6: This topographic map and 3-D model both depict a simple hill.
7. What is the pattern of the contour lines around a simple hill?
Slide 7: Focus in on the area of the valley between the 3000- and 4000-foot contours and observe how the contours represent the
shape of the land.
8. Make a sketch of the pattern of the contour lines moving up the valley. Draw an arrow to indicate the direction
in which water flows across the lines.
Slide 8 Examine the topographic map carefully. The small marks in the center of the feature are called hachures. Take some time to
study the map and predict the shape of the feature it depicts.
9. What landform feature does the model show, and what do hachures on contour lines indicate?
Slide 9: Examine this topographic map of Mount Shasta in California. Predict the shape of the feature inside the blue rectangle.
10. Describe the structure inside the box on the map.
Slide 10: Examine the topographic map below. Use what you’ve learned about reading topographic maps and contours to interpret
the shape of the landscape to answer question 11 below.
11. Identify the features marked at A and B. Where is the elevation highest on this map? Where is it lowest?