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      Permawhat?

Instructional Objectives
Background Information
Activity
Evaluation
Web Resources


Topic: Permafrost and its effect on human activity.

Instructional Objectives: Students will:

1. Identify the contents of permafrost found in the Denali Wilderness of Alaska.

2. Create permafrost in the classroom.

3. Describe the difference between permafrost in summer and in winter.

4. Construct a small structure on the classroom-created frozen permafrost model and predict/record what happens to the structure upon warming from summer heat.

Background Information:

One of the obstacles faced in building the Alaska Pipeline was the unstable nature of permafrost. Permafrost is found throughout Denali National Park at higher elevations. Permafrost freezes solid in winter but warm surface temperatures in summer melt the upper layer resulting in a soft, wet, spongy environment. For those building structures in such an environment, serious consideration must be given to the behavior of permafrost. (Source: Park Ranger presentation, Denali National Park, Park Headquarters, July, 1995)

Activity: Permawhat?

Time Needed For Activity: One 45 minute period to mix permafrost contents and build structures and one 45 minute period to observe, record and present results of activity.

Target Grade Level: Middle school (Extensions and adjustments for elementary and high school found below.)

Materials Needed: (Use Cooperative Groups of four and identify recorder, leader, reader, and investigator.)

  • One plastic shoebox
  • One liter of fresh water
  • .25 liter of small gravel stone
  • .25 liter of garden dirt
  • .25 liter of Sphagnum moss (Available from garden supply stores.)
  • Six toothpicks
  • One solid cubic piece of school clay, 6-7 cm on a side (in the shape of a small house)
  • A student science journal for recording activities
  • Safety glasses for each student

Procedures:

1. Distribute materials to students and have them mix small gravel, garden dirt, water, and Sphagnum moss into the plastic shoebox.

2. Freeze contents (or put outside in cold climates during winter months).

3. While permafrost is freezing, have students construct a small clay house with toothpicks as corner supports so that structure will rest on permafrost. Have students predict what will happen to the structure when placed on melting permafrost and enter predictions in student science journals.

4. Next day and after freezing, place small clay house on toothpick supports on top of permafrost and place near window to allow surface of frozen permafrost to be heated. Sunlight while slow is safest. (CAUTION: Using lamps or hair dryers as a heat source requires close teacher supervision due to electrical dangers near water.)

5. Observe and record what happens to the permafrost and the structure (small clay house on toothpick supports) as a journal entry and compare results from observations with the predictions made earlier. Also have groups discuss the hazards of building structures in locations like Denali. Record the temperature of the surface of the permafrost as it melts. Begin recording temperature immediately upon removing plastic container from freezer and graph the temperature (in degrees Celsius) results over time.

Evaluation/Alternative Assessment:

Have each group orally report their findings to the class from student science journals. Chart the results of each group complete discussion following individual presentations of students observations and teacher review of student science journal entries. Also, have students show graphs representing temperature changes of permafrost melting.

Extensions/Adjustments for Elementary:

Depending on elementary grade level and writing skills, collect data orally, have teacher record on blackboard and do not use journals.

Extensions/Adjustments for Secondary:

When mixing materials, use the metric system and have students convert to English system.

Measure temperature (about every ten minutes) of the permafrost when frozen solid and when thawed and record and graph the temperatures over a period of time. Enter data on a spreadsheet and compare results with different groups for analysis.

Use dry ice or provide an additional ice layer in a second container to keep the bottom of the permafrost frozen while the top thaws to create a more realistic environment.

Substitute small clay structure with a toothpick bridge similar to the one supporting the Alaska Pipeline. Have students observe and record results of the collapsing bridge. Also add additional mass to the bridge for a more dramatic effect.

Research the building of the Alaska Pipeline and determine the kinds of obstacles engineers faced in the construction.

Research and discuss the variable effect of permafrost on structures in the arctic during different seasons.

Web Resources:

http://www.alyeska-pipe.com/pipelinefacts.html

http://en.wikipedia.org/wiki/Trans-Alaska_Pipeline_System

http://www.valdezalaska.org/history/transAlaskaPipeline.html

http://abcnews.go.com/sections/scitech/DailyNews/warming_permafrost010207.html

http://fairbanks-alaska.com/permafrost.htm

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