Ms. Richard
CLASS SET
Objectives

Make a topographic map from a model.

Understand the meaning of contour line, contour interval, and relief.

Interpret topographic maps.

Recognize volcanic landforms on a topographic map, and predict where lava would flow on them.

Understand basic relationships between magma composition and type of volcano formed.
Standards Addressed

Earth Science o 3e. Students know there are two kinds of volcanoes: one kind with violent eruptions producing steep slopes and the other kind with voluminous lava flows producing gentle slopes.

Investigation and Experimentation
Materials

Plastic model of volcanic island, marker, water, beaker, food coloring, plastic top, transparency, metric ruler, map of Mt. St. Helens
Procedure
1.
Obtain a plastic model of a volcanic island, a marker, and a clear plastic lid.
2.
Draw horizontal marks up the side of the plastic model exactly 1cm apart. Each 1 cm space represents 100m of elevation with the bottom of the model representing zero meters.
3.
Obtain and fill a beaker with water and add three drops of food coloring.
4.
Fill the plastic model up to the 100m mark. Place the plastic lid on top and trace on the plastic lid with your marker the outline formed by the water. Make sure you look straight down as you trace.
5.
Repeat this process until you completely submerge the volcano. You have just created a topographic map of the volcanic island. The lines that you have made are called contour lines. These lines connect points on the island of equal elevation.
6.
Trace your topographic map onto your paper.
7.
Compare your map to the map of Mt. St. Helens shown below. a.
Describe two similarities between the maps.

Ms. Richard
CLASS SET b.
Note the legend on the map of Mt. St. Helens. Add a legend to your map.
Include a scale, north arrow, and contour interval. c.
What do the shaded regions on the map of Mt. St. Helens represent? d.
Why do the shaded regions cross the contour lines at right angles? e.
Which part of Mt. St. Helens is steeper, the slope between 1500m and 2000m, or the slope between 2000m and 2500m? Explain your answer. f.
What are the lowest and highest elevations on the map of Mt. St. Helens? What is the difference in elevation between these two points? g.
Note the locations A, B, C, and D on the map. If lava erupted at point A, would it flow to point B, C, or D? Explain why.
Analysis
1.
Explain the features on a topographic map.
2.
How would a topographic map show the direction of lava flow?
3.
How do topographic maps show the differences in types of volcanoes?
4.
How does the theory of plate tectonics relate to the formation of volcanoes?
5.
For the volcanoes shown in figures 2 and 5, sketch topographic maps. Show what the volcano would look like from above. Apply the general rules for interpreting topographic maps. Include a simple legend.