Permafrost

15 Points Per Correct Answer - No time limit  

1. Permafrost or permanently frozen ground is traditionally defined as: ground that remains at or below 0 degrees C for at least 2 years ground that has not been above 0 degrees C in historic times ground that remains at or below 0 degrees C for at least 1000 years ground that remains at or below 0 degrees C for at least 100 years

2. Permafrost covers what percentage of the earth's surface? about 25 percent about 50 percent about 10 percent about 5 percent

3. Where has the deepest penetration of permafrost been measured to date? Russia Alaska Antarctica Northern Canada

4. The distribution of permafrost is controlled by many variables but the most important is: latitude type of ground material climate geothermal heat

5. Which feature develops as a result of permafrost degradation? alas palsa pingo ice wedge