Instructional Objectives
Background Material
Procedure
Evaluation/Alternative Assessment:
Web Resources

Instructional Objectives:

Students will:

1. Set up a laboratory experiment to measure sample Namib Desert temperatures
2. Understand how the temperature of the Namib Desert is changed by sand which acts as an insulator
3. Graph the created desert temperatures measured in the activity
4. Identify how some species survive by burying themselves in the sand

Background Material:

The highest temperatures in the desert are on the surface of the sand. Lower temperatures can be found short distances above and below the surface of the sand. Temperatures in Namib can reach as high as 150 degrees on the surface of the sand. A fraction of an inch could mean a 30 degree temperature difference. The sand , as well as shade, act as insulators to the intense sunlight found in Namib Desert. (If you missed The Living Edens "Namib"program that aired on July 16, 1997 you can order the video).

Target Grade Level:

Middle Level Students, grades 6-8

Materials Needed:
(For each group of 3-4 students)

• A small hand held lamp with aluminum shade (such as commonly found in science kits) with a 100 watt or larger bulb for each group of students (the hotter the lamp, the more dramatic the temperature differences)
• One large cardboard box filled with sand approximately 8-10 inches deep for each group of students
• Four thermometers for each group of students to measure temperature. Each thermometer should have a temperature span of -10 degrees Celsius to 100 degrees Celsius
• Science Journals
• Scissors
• Pencils and graph paper for each group
• One hot pad or glove for each group
• A computer with access to the World Wide Web for the high school extension (optional)

Caution: Special care should be taken to prevent students from burn injury. Leaning against the hand held lamp with aluminum shade or touching the shade can be very hot and cause burns. Have a hot pad or glove available to hold the lamp or mount on a stand.

Procedure:
(See diagram for design of activity)

1. Hold lamp approximately 12 inches above the sand and plastic container
2. Heat area for approximately 20 minutes (or longer) and remove light/heat source from sand
3. Measure and record in science journals the temperature six inches above the sand, at the surface of the sand, three inches below the sand and at the bottom of the container. Be sure to place thermometers into the side of the box, in holes made with scissors to insulate them from the heat of the lamp
4. Graph all four temperature on a line graph

Evaluation/Alternative Assessment:

Compare and contrast the different temperatures and discuss reasons for such differences in a class meeting. Record reasons for differences, the results of the activity (temperatures) and place graphs in science journals. Display graphs of some students during discussion. Extend this discussion by considering other types of substrate, earth, rocks, etc.

Elementary Extension:

The above activity can be done in the elementary classroom. At the elementary level, this should be a teacher demonstration. Graphing of the temperatures can also be done by upper elementary students. Use care when using glass thermometers around younger children.

High School Extension:

Extensive study of desert temperatures around the world can be done through the World Wide Web. Students can gather data on the famous deserts around the world and record. Class discussion can center on comparing and contrasting the data collected.

Web Resources: