QUINZHEE
PURPOSE: To build a quinzhee and test its effectiveness as a snow shelter.
MATERIALS: Suitable winter clothing (wool or waterproof pants), snow shovel or snowshoe covered with plastic bag, thermometer, hand lens, flashlight, notebook and pencil, camera and film (optional).
INTRODUCTION: The best known snow shelter, the igloo, was developed by the Inuit people (Eskimos) of the tundra. In this land without trees, wind-driven snow (siqoq) breaks apart into small grains which pack together on the ground. These crystals then sinter (fuse together) to form a hard, dense snow mass (upsik) which is ideal for making igloos.
In the tree-covered taiga, or boreal forest, the snow (apun) remains loose because the trees greatly reduce the force of the wind. Here the Athabaskan people make a snow shelter called a quinzhee or powder snow cave.
In this activity you will explore the life-saving potential of the quinzhee. In an emergency situation, survival could depend on your ability to construct an adequate snow shelter. You may choose to sleep in your quinzhee overnight, but you must get permission before doing so.
PREDICTION: Use what you know about the insulating characteristics of snow to make a prediction.
1. Do you think the temperature inside a quinzhee sheltering a person for several hours will be higher, lower, or about equal to the freezing point of water? Explain your ideas.
PROCEDURE: You may wish to work with a partner. Document your quinzhee with photographs or sketches.
A. Find a site with deep loose snow and no underbrush. The site should be away from possible disturbances. Mark off a circle about 2.5 m in diameter. Use a shovel to pile snow in a mound in this area. Be sure to mix snow from the surface and bottom of the snowpack, lofting the snow as the pile is made. Keep the snow light and airy; avoid packing the snow. When completed, the pile of snow should measure about 1.5 m high by about 2.5 m in diameter at the base.
B. Immediately examine the snow crystals in the snow mound. Do this by carefully scraping a handful of crystals onto a dark colored cloth (glove or sleeve) and view them with your hand lens. Compare these crystals with the crystals you should now obtain by digging into the middle of the snowpack at a nearby undisturbed site. Sketch both sets of crystals below and describe the air spaces and any connections between the crystals.
C. After an hour or two (longer if the air temperature is near or above freezing), start tunneling into the base of the mound on the downwind side. The opening should only be large enough for the biggest person. When the quinzhee is hollowed out, the walls at the base should be at least 20-30 cm thick or more and the ceiling 35-40 cm. A thin stick can be used as a probe to determine this thickness. The snow made should be removed to the bare earth. Save a snow block to close off the entrance.
D. Make a 2-3 cm diameter vent hole at the top of the ceiling and a fresh air hole of the same size near the base of the door. Examine some snow crystals from the quinzhee to see if they have changed from observations made in step B. Sketch some quinzhee snow crystals below and describe the air spaces and any connections between the crystals.
E. Measure the air temperature 1.5 m above the surface of the snow away from the quinzhee. Record the data on the diagram below.
F. Bring the thermometer inside the quinzhee with you. Use a snow block to close the entrance. Measure the temperatures at locations indicated on the diagram after you have been in the quinzhee for at least an hour.
G. Repeat step E to obtain a second air temperature measurement outside the quinzhee.
H. If you plan to sleep in the quinzhee, you will need a warm sleeping bag and a foam rubber mat. If you have permission, the light branches of conifers like spruce and cedar could be used instead of the mat. The use of a candle is permissable but be sure to allow for more ventilation if used. Keep your clothing dry by removing the snow. Many winter campers recommend bringing your boots or boot liners into your sleeping bag with you.
DATA:
Mound Snow Crystals:
Crystals from Snowpack:
Quinzhee Snow Crystals:
Quinzhee Temperatures at X:
CONCLUSIONS:
2. Describe the differences between the snow crystals in the undisturbed snowpack and the snow crystals in the fresh snow mound.
3. Describe the differences between the snow crystals in the fresh snow mound and the snow crystals in the completed quinzhee.
4. Where did you find the warmest air temperature within the quinzhee? Where did you find the coldest air temperature within the quinzhee? Why is this so?
DISCUSSION:
5. How did the change in the snow crystal structure result in a sturdy snow shelter?
6. Would tunneling into a natural snowdrift in an emergency have the same effect as building a quinzhee?
7. Use your temperature data to explain the location and function of the vent holes.
8. When you occupied the quinzhee, why did the temperature increase?
9. What part of an unoccupied quinzhee do you expect to be the warmest? Consider the ceiling, walls, and floor (bare ground). What is the ultimate source of this heat?
10. Why was it necessary to remove the snow to the bare ground when building a quinzhee?
11. Why is loose snow better than packed snow for building a quinzhee?
12. What mammals and birds use the snow pack as a quinzhee-like shelter?
13. Did you enjoy yourself or would you prefer to sleep in your warm bed? Remember, in a survival situation you may not have that option!