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
Kelsey Lake Diamond Mine settled the lawsuit but in September 1997 Redaurum decided to liquidate its diamond properties to concentrate on exploration. The mine was operated sporadically until the operation was acquired by McKenzie Bay International Ltd. in 2000. McKenzie bought the mine management firm Diamond Co. from Chapter 11 bankruptcy, transferred all its assets to a subsidiary, Great Western Diamond Co., and invested $2 million in new equipment for the mine. In 2001, McKenzie tried to sell the mine to focus on mining vanadium after the price of that metal rose dramatically. However, due to a dispute with the landowner over royalty payments,