Contour Lines Show Elevation

Contour Lines Show Elevation 2015-16

HOW IS ELEVATION INDICATED ON A MAP ?

Background: Topographic maps are essential tools in geologic studies because they show the configuration of the earth’s surface in remarkable

detail and permit one to measure horizontal distances and vertical elevations. This is accomplished by means of contour lines; line that connects

points of equal elevation. Contour interval is the difference in elevation between any two adjacent contour lines. Relief is the difference in

elevation between the top and bottom of the area.

Materials: plastic model land form, food coloring (do not spill, it stains), water, beaker, water soluble marker

Procedure:

1. Fill the beaker approximately 3/4 full of tap water. Add more water as need be.

2. Put one drop of food coloring in the beaker of water.

3. Using the water soluble maker, make marks every 1 cm on the side of the plastic box.

4. Trace the outline of the 3-dimensional mountain-shape on the lid of the box using the water soluble marker. Label this line 0 centimeters.

Be extremely careful to be looking from directly over the lid of the box. If you are looking at an angle the results will be inaccurate. Additionally,

have only one eye open while you are tracing the outline.

5 Take the lid off the box and pour the colored water into the box to first mark on the side.

6. Place the lid back on and trace the water line on the top of the box. Label the line you just drew 1 centimeter. That line represents every

point on that figure that is exactly 1 centimeter high. Therefore, it is called the 1 centimeter contour line.

7. Increase the water level by 1 centimeter by pouring the colored water into the box to a height of 2 centimeters.

8. Trace the water line on the lid of the box. Label the line you just drew is 2 centimeters.

9. Repeat the process of adding water and tracing until you have the object mapped.

10. Take the completed drawing to the overhead projector and place a sheet of white paper over the lid of the box and trace thelid of the box

and trace the lines you just drew. Label each of the contour lines. Turn in one tracing per group.

Analysis: The following are to be done by each individual. You are encouraged to discuss the questions, but under no circumstances are you to share answers. Take care to respond to the questions in your own words.

1. What is the elevation of the first contour line you drew ? ______

2. What is the elevation of the last contour line you drew ? ______

3. What is the relief of that mountain ? ______

4. What is the contour interval of this tracing ? ______

5. Is the elevation of the last contour line you drew the elevation of the top of the mountain ? ______

The elevation of the top of the mountain is in what range ? ______(example 5 -6 centimeters) P

Explain your answer. ______

______

6. Label on the tracing the side of the mountain that is steepest. How did you determine this ? ______

______

7. Contour lines that cross valleys or ravines bend out of line with the rest of each contour loop. Do your contour lines bend upstream or downstream

when they cross the valley or ravine ? ______