ALBERT

Description: 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 (Gt) of organic carbon in perennially-frozen archives. Hence, here we synthesize data on the circum-Arctic and sub-Arctic distribution and thickness of Yedoma for compiling a preliminary circum-polar Yedoma map (see figure). For compiling this map, we used (1) maps of the previous Yedoma coverage estimates, (2) included the digitized areas from Grosse et al. (2013) as well as extracted areas of potential Yedoma distribution from additional surface geological and Quaternary geological maps (1.: 1:500,000: Q-51-V,G; P-51-A,B; P-52-A,B; Q-52-V,G; P-52-V,G; Q-51-A,B; R-51-V,G; R-52-V,G; R-52-A,B; 2.: 1:1,000,000: P-50-51; P-52-53; P-58-59; Q-42-43; Q-44-45; Q-50-51; Q-52-53; Q-54-55; Q-56-57; Q-58-59; Q-60; R-(40)-42; R-43-(45); R-(45)-47; R-48-(50); R-51; R-53-(55); R-(55)-57; R-58-(60); S-44-46; S-47-49; S-50-52; S-53-55; 3.: 1:2,500,000: Quaternary map of the territory of Russian Federation, 4.: Alaska Permafrost Map). The digitalization was done using GIS techniques (ArcGIS) and vectorization of raster Images (Adobe Photoshop and Illustrator). Data on Yedoma thickness are obtained from boreholes and exposures reported in the scientific literature. The map and database are still preliminary and will have to undergo a technical and scientific vetting and review process. In their current form, we included a range of attributes for Yedoma area polygons based on lithological and stratigraphical information from the original source maps as well as a confidence level for our classification of an area as Yedoma (3 stages: confirmed, likely, or uncertain). In its current version, our database includes more than 365 boreholes and exposures and more than 2000 digitized Yedoma areas. We expect that the database will continue to grow. In this preliminary stage, we estimate the Northern Hemisphere Yedoma deposit area to cover approximately 625,000 km². We estimate that 53% of the total Yedoma area today is located in the tundra zone, 47% in the taiga zone. Separated from west to east, 29% of the Yedoma area is found in North America and 71 % in North Asia. The latter include 9% in West Siberia, 11% in Central Siberia, 44% in East Siberia and 7% in Far East Russia. Adding the recent maximum Yedoma region (including all Yedoma uplands, thermokarst lakes and basins, and river valleys) of 1.4 million km² (see figure and Strauss et al. (2013)) and postulating that Yedoma occupied up to 80% of the adjacent formerly exposed and now flooded Beringia shelves (1.9 million km², down to 125 m below modern sea level, between 105°E – 128°W and 〉68°N), we assume that the Last Glacial Maximum Yedoma region likely covered more than 3 million km² of Beringia. Acknowledgements: This project is part of the Action Group “The Yedoma Region: A Synthesis of Circum-Arctic Distribution and Thickness” (funded by the International Permafrost Association (IPA) to J. Strauss) and is embedded into the Permafrost Carbon Network (working group Yedoma Carbon Stocks). We acknowledge the support by the European Research Council (Starting Grant #338335), the German Federal Ministry of Education and Research (Grant 01DM12011 and “CarboPerm” (03G0836A)), the Initiative and Networking Fund of the Helmholtz Association (#ERC-0013) and the German Federal Environment Agency (UBA, project UFOPLAN FKZ 3712 41 106). References Grosse, G., Robinson, J.E., Bryant, R., Taylor, M.D., Harper, W., DeMasi, A., Kyker-Snowman, E., Veremeeva, A., Schirrmeister, L. and Harden, J., 2013. Distribution of late Pleistocene ice-rich syngenetic permafrost of the Yedoma Suite in east and central Siberia, Russia. US Geological Survey Open File Report, 1078. U.S. Geological Survey Reston, Virginia, 37 pp. Strauss, J., Schirrmeister, L., Grosse, G., Wetterich, S., Ulrich, M., Herzschuh, U. and Hubberten, H.-W., 2013. The Deep Permafrost Carbon Pool of the Yedoma Region in Siberia and Alaska. Geophysical Research Letters, 40: 6165–6170, doi:10.1002/2013GL058088. Walter Anthony, K.M., Zimov, S.A., Grosse, G., Jones, M.C., Anthony, P.M., Chapin III, F.S., Finlay, J.C., Mack, M.C., Davydov, S., Frenzel, P. and Frolking, S., 2014. A shift of thermokarst lakes from carbon sources to sinks during the Holocene epoch. Nature, 511: 452–456, doi:10.1038/nature13560.

Description: The Lena River Delta is underlain by permafrost. Thus, it is highly vulnerable to climate warming and may degrade in different ways, by shoreline erosion, land surface subsidence, deepening of the seasonal thawing front, and development of rapid thaw features such as lakes, gullies and landslides.

Description: The expedition „BERINGIA/KOLYMA 2008“ focused on combined studies of permafrost sequences at Duvanny Yar (Lower Kolyma River) using boreholes and outcrops along the riverbank. Expected results of cryolithological and stratigraphical studies will be used as a reference for comparison and correlation with results of similar studies of permafrost sequences around the Laptev and the East Siberian Seas between 1998 and 2007 (Russian-German science cooperation SYSTEM LAPTEV SEA). Furthermore, in the course of the International Polar Year new sites were added to the IPY-monitoring program TSP (Thermal State of Permafrost). In preparation of the upcoming joint German-Russian Research project POLYGON dealing with the development and monitoring of polygonal landscapes local conditions and stakeholders in Cherskii were explored and preliminary studies in several thermokarst lakes and small ponds were undertaken. The topics of the fieldwork in August 2008 were the following: - Permafrost temperature monitoring (TSP) - Borehole studies - Gas measurements - Microbiological studies - Radiometry - Modern cryosoils - Cryolithology - Stratigraphy - Geochronology - Limnology

Description: Lagoon development in ice-rich permafrost environments such as the Alaskan Beaufort Sea coastline and the Yedoma coastlines of northern Siberia represents a key mechanism of marine inundation of permafrost along the Arctic coastal plains. Here we show lithological, geochronological, and geochemical data from a core drilled in 1999 in Ivashkina Lagoon on the Bykovsky Peninsula in northeastern Siberia. This study extends previous studies of the Ivashkina Lagoon, and provides a first dated geochronological context for sedimentation and lithological characteristics. In addition, we report ground temperature measurements from different borehole sites in and around the lagoon to support our analysis of the thermokarst lagoon environment. Furthermore, a change detection study was carried out using historical aerial photography and modern satellite imagery for the 1982 to 2016 period. Several stages of landscape dynamics were reconstructed, starting with an initial Yedoma Ice Complex that covered the area during the late Pleistocene and which was locally thawed by thermokarst lake development during the Late Glacial with subsequent lacustrine sedimentation. A final stage completed the landscape dynamics during the last few hundreds of years. This stage was characterized by lake drainage and lagoon development, including strong reworking of surface sediments. By extrapolating the organic carbon data from Ivashkina Lagoon to the lagoons of the Bykovsky Peninsula, we estimate that lagoons contain 1.68 ± 0.04 Mt of organic carbon in their upper 6 m.

Description: Permafrost in Sibirien taut, und das auf verschiedene Weise. Besonders gut sichtbar sind Küstenerosion und Bodenabsenkungen, oder wenn vorhandene Straßen, Häuser und andere Infrastruktur dadurch beschädigt wird. Doch auch eine Vertiefung der sommerlichen Auftauschicht und Entstehung von Seen, was zu schnellen Auftauprozessen (Thermokarst) führt, machen die Permafrostregion zu einer Region, in der der Klimawandel heute deutlich sichtbar wird.

Description: The response of permafrost to submergence can vary between ice-rich late Pleistocene deposits and the thermokarst basins that thawed out during the Holocene. We hypothesize that inundated Alases offshore thaw faster than submerged Yedoma. To test this hypothesis, we estimated depths to the top of ice-bearing permafrost offshore of the Bykovsky Peninsula in northeast Siberia using electrical resistivity surveys. The surveys traversed submerged lagoon deposits, drained and refrozen Alas deposits, and undisturbed Yedoma from the coastline to 373 m offshore. While the permafrost degradation rates of the submerged Yedoma were in the range of similar sites, the submerged Alas permafrost degradation rates were up to 170% faster. Given the abundance of thermokarst basins and lakes along parts of the Arctic coastline, its effect on subsea permafrost degradation must be similarly prevalent. Remote sensing analyses suggest that 54% of lagoons wider than 500 m originated in thermokarst basins.