Argyle diamond mine at the Ekati mine, both in Canada. However, Argyle has two to four times the concentration of diamonds (ore grade) of these mines. This makes extraction economically feasible, as mine costs are mostly related to the amount of ore processed, not the amount of diamond extracted. In 2005, Rio Tinto was given the go-ahead to a future expansion project, moving it from an open pit to an underground mine. This plan was postponed; in September 2010 Rio Tinto announced fresh plans to develop an underground mine beneath the existing pit, increasing annual production to 9 million tonnes of ore. The
Permafrost carbon cycle to the atmosphere. Carbon stored within arctic soils and permafrost is susceptible to release due to several different mechanisms. Carbon that is stored in permafrost is released back into the atmosphere as either carbon dioxide (CO) or methane (CH). Aerobic respiration releases carbon dioxide, while anaerobic respiration releases methane. Carbon is continually cycling between soils, vegetation, and the atmosphere. Currently, carbon flux from permafrost soils is minimal, however studies suggest that future warming and permafrost degradation will increase the CO flux from the soils. Thaw deepens the active layer, exposing old carbon that has been in storage for decades, to