| 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
|
