The genesis of Yedoma Ice Complex permafrost – grain-size endmember modeling analysis from Siberia and Alaska


Contact
Lutz.Schirrmeister [ at ] awi.de

Abstract

The late Pleistocene Yedoma Ice Complex is an ice-rich and organic-bearing type of permafrost deposit widely distributed across Beringia and is assumed to be especially prone to deep degradation with warming temperature, which is a potential tipping point of the climate system. To better understand Yedoma formation, its local characteristics, and its regional sedimentological composition, we compiled the grain-size distributions (GSDs) of 771 samples from 23 Yedoma locations across the Arctic; samples from sites located close together were pooled to form 17 study sites. In addition, we studied 160 samples from three non-Yedoma ice-wedge polygon and floodplain sites for the comparison of Yedoma samples with Holocene depositional environments. The multimodal GSDs indicate that a variety of sediment production, transport, and depositional processes were involved in Yedoma formation. To disentangle these processes, a robust endmember modeling analysis (rEMMA) was performed. Nine robust grain-size endmembers (rEMs) characterize Yedoma deposits across Beringia. The study sites of Yedoma deposits were finally classified using cluster analysis. The resulting four clusters consisted of two to five sites that are distributed randomly across northeastern Siberia and Alaska, suggesting that the differences are associated with rather local conditions. In contrast to prior studies suggesting a largely aeolian contribution to Yedoma sedimentation, the wide range of rEMs indicates that aeolian sedimentation processes cannot explain the entire variability found in GSDs of Yedoma deposits. Instead, Yedoma sedimentation is controlled by local conditions such as source rocks and weathering processes, nearby paleotopography, and diverse sediment transport processes. Our findings support the hypothesis of a polygenetic Yedoma origin involving alluvial, fluvial, and niveo-aeolian transport; accumulation in ponding waters; and in situ frost weathering as well as postdepositional processes of solifluction, cryoturbation, and pedogenesis. The characteristic rEM composition of the Yedoma clusters will help to improve how grain-size-dependent parameters in permafrost models and soil carbon budgets are considered. Our results show the characteristic properties of ice-rich Yedoma deposits in the terrestrial Arctic. Characterizing and quantifying site-specific past depositional processes is crucial for elucidating and understanding the trajectories of this unique kind of ice-rich permafrost in a warmer future.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Research Networks
Peer revision
Peer-reviewed, Web of Science / Scopus
Publication Status
Published
Eprint ID
52054
DOI 10.5194/egqsj-69-33-2020

Cite as
Schirrmeister, L. , Dietze, E. , Matthes, H. , Grosse, G. , Strauss, J. , Laboor, S. , Ulrich, M. , Kienast, F. and Wetterich, S. (2020): The genesis of Yedoma Ice Complex permafrost – grain-size endmember modeling analysis from Siberia and Alaska , E&G Quaternary Sci. J., 69 , pp. 33-53 . doi: 10.5194/egqsj-69-33-2020


Download
[thumbnail of Schirrmeister_et_al_egqsj-69-33-2020.pdf]
Preview
PDF
Schirrmeister_et_al_egqsj-69-33-2020.pdf

Download (8MB) | Preview
[thumbnail of Schirrmeister_et_al_egqsj-69-33-2020-supplement.pdf]
Preview
PDF
Schirrmeister_et_al_egqsj-69-33-2020-supplement.pdf

Download (2MB) | Preview

Share


Citation

Geographical region

Research Platforms

Campaigns
Arctic Land Expeditions > AK-Land_2004_Fairbanks_Barrow
Arctic Land Expeditions > AK-Land_2006_Fairbanks_Barrow
Arctic Land Expeditions > RU-Land_2012_Lena_BuorKhaya
Arctic Land Expeditions > RU-Land_2012_Kytalyk_Kolyma
Arctic Land Expeditions > RU-Land_2011_Kytalyk
Arctic Land Expeditions > RU-Land_2005_Lena
Arctic Land Expeditions > RU-Land_2007_Lena
Arctic Land Expeditions > RU-Land_2010_Lena
Arctic Land Expeditions > RU-Land_1998_Lena
Arctic Land Expeditions > RU-Land_1999_Lena
Arctic Land Expeditions > RU-Land_2000_Lena
Arctic Land Expeditions > RU-Land_2003_Lena_Anabar
Arctic Land Expeditions > RU-Land_2008_Kolyma
Arctic Land Expeditions > RU-Land_2013_Yakutia

Funded by
eu-repo/grantAgreement/EC/FP7/338335


Actions
Edit Item Edit Item