Volcano Contour Models Activity
Purpose
The purpose of this activity is to familiarize students with topography and the connection
between contour lines and elevation.
Objective
The goal of this activity is to create and interpret a contour map using the volcano model.
Time Needed
45 minutes
CA State Science Standards (9-12):
Investigation and Experimentation Standard:
1.h. "Read and interpret topographic and geologic maps."
1.m. "Investigate a science-based societal issue, "e.g..." land and water use
decisions in California."
Background Information
Topographic maps are 2-dimensional representations of a 3 dimensional surface.
Contour lines are used to show vertical elevation. Each contour line represents a line of
equal elevation on earth’s surface. Sea level is the zero elevation contour line. Contour
line basics: Contour lines do not cross but may converge at locations that are steeply
sloped. The farther apart the contour lines are spaced, the more gently sloped the
represented surface is (gradient). The elevation difference between two adjacent contour
lines is called the contour interval. Concentric contours represent hills. Contour lines
take a V-shape pointing upstream or uphill where they cross rivers or the lowest point in
a valley.
V-Shaped Contours
Saddle
Ridge
Hill
Valley
Key Terms
Contour line
Elevation
Hill
Ridge
Valley
Relief
Scale
Gradient
Topography
Materials Needed
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Plastic topographic volcano models (contour model kit available from Wards
Natural Science or Carolina Biological)
Clear overlay sheets
Non-permanent/erasable colored markers
Blue food coloring
Water
Cups or Pitcher to hold water
Drawing paper
Pencils
Ruler
Activity
1. On the side of the volcano model container make a tick mark every ½ inch and
label your marks in intervals of 100 feet. These lines will represent the different
levels to fill the container with water.
2. Tape the plastic sheet to container cover
3. Pour water into the plastic container to the first "fill line" (100 feet or whatever
your first elevation mark is) noting that it partially covers the base of the
mountain.
4. Draw a contour line on the plastic sheet by tracing the contact of the water with
the plastic volcano and label its elevation. In essence you are tracing the
shoreline.
5. Pour water to the next fill line and repeat the procedure of drawing another
contour line by tracing the water contact with the model, continue until you reach
the top of the model. Every time you increase the water level it is as if you are
increasing sea level and tracing the new shoreline.
6. On a piece of paper, have students draw a picture of their volcano model in any
style they like. After they spend a few minutes trying to represent their volcano on
a flat piece of paper, ask them the following questions.
Questions
1. How would you describe the shape of your plastic model (mountain)?
Approximate its total elevation based on the scale that you have drawn. Is it
symmetrical or does it have different shapes on different sides of the mountain? Is
it steep or a gentle slope? (to answer this question, consider which side of the
mountain you would hike up if you wanted a really strenuous hike vs. if you
wanted an easier hike)
2. How would you describe the contour line that you have drawn (circular, oblong,
elliptical)? What aspect of the mountain does it represent?
3. How would you describe the second contour line that you have drawn? Is it the
same shape as the first contour (it's the same basic shape and parallels the first
contour line, but it depends on the slope/gradient on the different sides of the hill)
4. How would you describe the shapes of the contour lines, do you see any patterns
or particular characteristics? (the more perfectly circular the contours are the more
symmetrical the mountain is) What do you notice about the distance/spacing
between the contour lines on various sides of the mountain (the steeper the slope
the more closely spaced the contour lines are) When are you looking at a high
point? When are you looking at a valley?
5. Do you think contour lines are an effective way to represent elevation? What can
you learn about a landscape by looking at a map of contour lines?