Thermokarst landscape, Interior Alaska near Fairbanks.

November 4, 2014 in post by Fortier.D

Yedoma deposits (Late Pleistocene sedimentation and freezing in unglaciated areas) are extremely ice-rich. Over time thermokarst modifies the landscape to trigger the developments of various landforms, here along and in an alluvial plain with meandering river. In this picture, we can observe several thermokarst lakes, some of which were drained, thaw ponds, peatlands, peat edge along lake margins, and collapsed bogs (Photo D. Fortier © Geocryolab). Fluvial activity plays a role in the life-cycle of these aquatic thermokarst ecosystems, draining ponds and lakes as rivers meander. Thermokarst landscape can play an important role in the climate system by releasing carbon sequestrated in the permafrost back to the atmosphere via oxidation and microbial activity.



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