Ice-Rich Yedoma Permafrost: A Synthesis of Northern Hemisphere Distribution and Thickness (IPA Action Group)

• Main Authors: Strauss, Jens, Fedorov, Alexander N., Fortier, Daniel, Froese, Duane, Fuchs, Matthias, Grosse, Guido, Günther, Frank, Harden, Jennifer W., Hugelius, Gustaf, Kanevskiy, Mikhail, Kholodov, Aleksander L., Kunitsky, Viktor V., Kraev, Gleb, Laboor, Sebastian, Lapointe Elmrabti, Lyna, Lozhkin, Anatoly V., Rivkina, Elizaveta, Robinson, Joel, Schirrmeister, Lutz, Shmelev, Denis, Shur, Yuri, Siegert, Christine, Spektor, Valentin V., Ulrich, Mathias, Vartanyan, Sergey, Veremeeva, Alexandra, Walter Anthony, Katey M., Zimov, Sergei
• Format: Conference Object
• Language: unknown
• Published: 2016
• Subjects: Ice; permafrost; Thermokarst; Tundra; wedge*; Alaska; Siberia; Yukon
• Online Access: https://epic.awi.de/id/eprint/41174/; https://hdl.handle.net/10013/epic.48124

Vast portions of Arctic and sub-Arctic Siberia, Alaska and the Yukon Territory are covered by ice-rich silty to sandy deposits that are containing large ice wedges, resulting from syngenetic sedimentation and freezing. Accompanied by wedge-ice growth in polygonal landscapes, the sedimentation process was driven by cold continental climatic and environmental conditions in unglaciated regions during the late Pleistocene, inducing the accumulation of the unique Yedoma deposits up to >50 meters thick. Because of fast incorporation of organic material into syngenetic permafrost during its formation, Yedoma deposits include well-preserved organic matter. Ice-rich deposits like Yedoma are especially prone to degradation triggered by climate changes or human activity. When Yedoma deposits degrade, large amounts of sequestered organic carbon as well as other nutrients are released and become part of active biogeochemical cycling. This could be of global significance for future climate warming as increased permafrost thaw is likely to lead to a positive feedback through enhanced greenhouse gas fluxes. Therefore, a detailed assessment of the current Yedoma deposit coverage and its volume is of importance to estimate its potential response to future climate changes. We synthesized the map of the coverage (see figure) and thickness estimation, which will provide critical data needed for further research. In particular, this preliminary Yedoma map is a great step forward to understand the spatial heterogeneity of Yedoma deposits and its regional coverage. There will be further applications in the context of reconstructing paleo-environmental dynamics and past ecosystems like the mammoth-steppe-tundra, or ground ice distribution including future thermokarst vulnerability. Moreover, the map will be a crucial improvement of the data basis needed to refine the present-day Yedoma permafrost organic carbon inventory, which is assumed to be between 83±12 (Strauss et al., 2013) and 129±30 (Walter Anthony et al., 2014) gigatonnes ...