25pts
#:
Name:
Date:
Period:
Intro to Physical Science
Topographic Map Activity
A. Purpose
To create a 2-dimensional topographic map that represents a (real-life!) 3-dimensional
volcano. (The volcano is called “Mount Capulin,” it is a steep-sided volcano located in
New Mexico, USA).
B. Materials
1 Plastic mountain model
1 Clear plastic box with top
1 Clear acetate sheet, 6”x11.5”
1 Washable marking pen
1 Large glass beaker
1 Metric ruler
C. Introduction
Topographic maps show Earth’s three-dimensional surface in two-dimensions.
Topographic maps use contour lines to show elevation (how high a surface is above sealevel). Contour lines, as seen on Earth’s surface, are closed curves at a constant elevation.
Contour lines are always perpendicular to the slope of a surface at any point. Contour
lines form complete circles that may extend off the edge of the topographic map. These
maps are important for geologists, hikers, campers, and anyone else interested in the
three-dimensional shape of the land.
The contour interval is the constant difference between adjacent (side-by-side)
contour lines. Closely spaced contour lines on a map show a surface with a steep slope.
Drainage features (where water flows) such as gullies, streams, or rivers are shown on a
topographic map by a consistent dip in the contour lines as each crosses the thread of
the stream at right angles.
D. Procedure
1. Using tape, secure the mountain model to a piece of white paper to the bottom of
the box to so you can see the water line when water is added to the box.
2. Use your washable marker to make marks one centimeter apart up the side of the
box (on the outside).
3. Label this elevation scale using zero at the bottom
4. Carefully fill the box with water until you reach your first mark. The resulting
“shoreline” matches the definition of a contour line since it is at a constant
elevation. (Observing this is the whole point of the activity!)
5. Now, cover your box with its lid and place your clear plastic acetate sheet on top
of the lid.
6. Use your washable ink pen to trace the shoreline border between the water and
mountain. You have just created a contour line on your topographic map.
7. Remove the lid to your box and carefully add enough water to bring the level to
the next mark. Hold the mountain tightly to the bottom if necessary.
8. Repeat Steps 5-7 until the mountain is totally submerged.
9. You have successfully created a topographic map of Mount Capulin on your clear
plastic sheet! Now, transfer this sheet onto a separate white piece of paper in the
“Activity” section of this lab.
E. Activity
Transfer your topographic map to a white piece of paper. A complete project
includes the following:
1. Neat, accurate contour lines. (5pts)
2. COLOR! (5pts)
3. Labels on STEEP and Gentle Slopes. (5pts)
4. Accurate labels on contour lines: Note—One centimeter scales to about 250 feet
on the actual volcano. If the bottom of the box represents an elevation of 6,280
feet above sea-level, the contours on the chart can be labeled to correspond to
the actual volcano. (5pts)
F. Analysis
1. Describe the general shape of the contour lines. (OBSERVE)
2. What general statement can be made about the closeness of the lines and the
steepness of the slope of the volcano? (hint: look at your topographic map and
your plastic model)
3. Describe how the solidified lava flows have affected the pattern of the contour
lines. (OBSERVE)
4. How would a steep valley down the side of the volcano change the contour
pattern?
5. Would it be possible to distinguish a basin from a mountain on a topographic map?
(Note: a “Basin” is a big hole in the ground; like a “reverse mountain”)