The Batagay mega thaw slump, Yana Uplands, Yakutia, Russia: permafrost thaw dynamics on decadal time scale

• Main Authors: Günther, Frank, Grosse, Guido, Wetterich, Sebastian, Jones, Benjamin M., Kunitsky, Viktor V., Kienast, Frank, Schirrmeister, Lutz
• Format: Conference Object
• Language: unknown
• Published: TERRA NOSTRA - Schriften der GeoUnion Alfred-Wegener-Stiftung 2015
• Subjects: Arctic; Climate change; glacier; glacier*; Ice; laptev; permafrost; Thermokarst; wedge*; Yakutia; Siberia
• Online Access: https://epic.awi.de/id/eprint/38008/; https://epic.awi.de/id/eprint/38008/1/PastGateways_2015.pdf; https://hdl.handle.net/10013/epic.45563; https://hdl.handle.net/10013/epic.45563.d001

Ice-rich permafrost that formed in glacial periods of the Quaternary is highly vulnerable to thaw under ongoing climate change and anthropogenic disturbance. Permafrost degradation processes such as thermokarst, thermo-denudation and thermo-erosion are actively shaping modern periglacial landscapes. Retrogressive thaw slumps – also referred to as thermo-cirques – represent a highly dynamic geomorphologic feature in ice-rich permafrost regions. These rapidly forming landforms consist of a steep headwall surrounding a gently inclined slump floor where sediment erosion and accumulation takes place simulatenously and develop as a result of rapid permafrost thaw over several decades. Thaw slumps are commonly found in permafrost areas with near-surface, thick ground-ice layers that are susceptible to thermo-denudation and subsequent mass displacement through cryogenic landslides (Leibman et al., 2008). Thaw slumps are particularly frequent along riverbanks and coastlines in the Northwest American and West Siberian Arctic, where they are typically initiated by lateral erosion of the bluff toe. In these regions, buried glacier ice (massive ground ice) bodies or ice-rich glacial till have been mapped. Given their exceptional size of up to 40 ha in area and 25 m high headwalls, so-called mega slumps in northwestern Canada represent primary terrain destabilization features with different environmental settings than surrounding areas (Lantuit et al., 2012), but are a significant source for sediment and solute delivery to adjacent lakes and streams (Kokelj et al., 2013). However, in East Siberia, retrogressive thaw slumps have been described in the syngenetic Late Pleistocene Ice Complex (Yedoma) permafrost deposits, where massive ice wedges and segregated intrasedimentary ice results in total volumetric ice contents of up to 80-90%. Such retrogressive thaw slumps in syngenetic permafrost were investigated for example on the coastal area of the Dmitry Laptev Strait (Are et al., 2005). However, Yedoma deposits are also found ...