Autor: Roger J. E. Brown

Permafrost is the thermal condition of the earth’s crust when its temperature has been below 32°F continuously for a number of years. Half of Canada’s land surface lies in the permafrost region—eithe …

Permafrost is the thermal condition of the earth’s crust when its temperature has been below 32°F continuously for a number of years. Half of Canada’s land surface lies in the permafr …