EARTHSS 21 Lecture Notes - Lecture 11: Thermokarst, Permafrost, Subsidence
23 Jul 2016
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Document Summary
The formation of ice wedges only happens in the permafrost layer. Permafrost being impermeable leads to the buildup of lakes (very shallow) Thicker active layer has led to greening (of the arctic) Drunken forests: land surface slants trees slant. Subsidence: big holes are opening underneath (big problem for roads) Depletion of lakes: depended on for water supply (leading to water stress) Gray areas: permafrost that will disappear (primarily up north) This soil has a lot of carbon accelerate climate change. Carbon is in vegetation, the atmosphere, sediments, oceans. Carbon dioxide vs. methane: more carbon dioxide at places with oxygen, more methane at places without oxygen. There is a lot of water in the arctic and therefore, a lot of oxygen (carbon dioxide is more prevalent) Bottom of lake no oxygen (methane is more prevalent) Soil accumulates carbon when it"s frozen: warming: huge store of carbon will be released.
