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
Dominion Diamond Mines Ekati combined are estimated to produce over 7 million carats of diamonds in 2014, worth an estimated $1.1 billion. Diavik and Ekati are currently ranked the 9th and 19th largest diamond mines in the world, respectively, according to total carat production. The company's participation in the retail segment of the diamond pipeline was by means of its ownership of Harry Winston, Inc., a chain of retail stores. On January 14, 2013 the company announced that it has entered into an agreement to sell its luxury brand diamond jewelry and timepiece division, Harry Winston Inc., to The Swatch Group Ltd. for