Permafrost by permafrost. Of this area slightly more than half is underlain by continuous permafrost, around 20 percent by discontinuous permafrost, and a little less than 30 percent by sporadic permafrost. Most of this area is found in Siberia, northern Canada, Alaska and Greenland. Beneath the active layer annual temperature swings of permafrost become smaller with depth. The deepest depth of permafrost occurs where geothermal heat maintains a temperature above freezing. Above that bottom limit there may be permafrost, whose temperature doesn't change annually—"isothermal permafrost". Permafrost typically forms in any climate where the mean annual air temperature is less than the
Gahcho Kue Diamond Mine Gahcho Kue Diamond Mine The Gahcho Kué Diamond Mine is located on the Canadian tundra in the Northwest Territories. It is situated at Kennady Lake (), in the Akaitcho Treaty 8 Territory AK claim block, which is southeast of the Snap Lake Diamond Mine and approximately east northeast of Yellowknife. The site is served by Gahcho Kue Aerodrome, which has both an ice runway in winter and a year-round gravel runway, and a spur of the Tibbitt to Contwoyto Winter Road from Lupin Mine. the main camp is at , north of the ice strip, with a smaller site at