Timing and drivers of mid- to late Holocene ice-wedge polygon development in the Western Canadian Arctic

• Main Authors: Wolter, Juliane, Lantuit, Hugues, Wetterich, Sebastian, Rethemeyer, Janet, Fritz, Michael
• Format: Conference Object
• Language: unknown
• Published: 2018
• Subjects: Arctic; Thermokarst; Yukon
• Online Access: https://epic.awi.de/id/eprint/47514/; https://epic.awi.de/id/eprint/47514/1/Wolter_EUCOP2018_extended_abstract_template_01_09_2017.pdf; https://eucop2018.sciencesconf.org/data/EUCOP5_2018_Book_of_abstracts.pdf; https://hdl.handle.net/10013/epic.b30ceaa7-1d5d-4957-b90d-b626e864827c

Ice-wedge polygon formation and development from low-centred to high-centred types are thought to be either linear processes acting on long time-scales or rapid shifts between different regimes. We analyzed six sediment cores from three ice-wedge polygons on the Yukon Coastal Plain to examine the timing and drivers of these dynamics. All sites developed from shallow lakes or submerged polygon environments to low-centred polygons before rapid degradation and drying during the last century. We found that ice-wedge polygon initiation was linked to moderate climatic cooling during the mid-Holocene combined with drainage of lakes. The further conversion to high-centred polygons appeared to have been a rapid process linked to modern climatic warming. Continued warming may thus lead to increasing ice-wedge melt on larger scales and subsequent degradation of ice-wedge polygons, especially if paired with increasing geomorphic disturbances caused by thermokarst and thermo-erosion.