TY  - GEN
A1  - Jongejans, Loeka L.
A1  - Strauss, Jens
A1  - Lenz, Josefine
A1  - Peterse, Francien
A1  - Mangelsdorf, Kai
A1  - Fuchs, Matthias
A1  - Grosse, Guido
T1  - Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - As Arctic warming continues and permafrost thaws, more soil and sedimentary organic matter (OM) will be decomposed in northern high latitudes. Still, uncertainties remain in the quality of the OM and the size of the organic carbon (OC) pools stored in different deposit types of permafrost landscapes. This study presents OM data from deep permafrost and lake deposits on the Baldwin Peninsula which is located in the southern portion of the continuous permafrost zone in west Alaska. Sediment samples from yedoma and drained thermokarst lake basin (DTLB) deposits as well as thermokarst lake sediments were analyzed for cryostratigraphical and biogeochemical parameters and their lipid biomarker composition to identify the below-ground OC pool size and OM quality of ice-rich permafrost on the Baldwin Peninsula. We provide the first detailed characterization of yedoma deposits on Baldwin Peninsula. We show that three-quarters of soil OC in the frozen deposits of the study region (total of 68 Mt) is stored in DTLB deposits (52 Mt) and one-quarter in the frozen yedoma deposits (16 Mt). The lake sediments contain a relatively small OC pool (4 Mt), but have the highest volumetric OC content (93 kgm(-3)) compared to the DTLB (35 kgm(-3)) and yedoma deposits (8 kgm(-3)), largely due to differences in the ground ice content. The biomarker analysis indicates that the OM in both yedoma and DTLB deposits is mainly of terrestrial origin. Nevertheless, the relatively high carbon preference index of plant leaf waxes in combination with a lack of a degradation trend with depth in the yedoma deposits indi-cates that OM stored in yedoma is less degraded than that stored in DTLB deposits. This suggests that OM in yedoma has a higher potential for decomposition upon thaw, despite the relatively small size of this pool. These findings show that the use of lipid biomarker analysis is valuable in the assessment of the potential future greenhouse gas emissions from thawing permafrost, especially because this area, close to the discontinuous permafrost boundary, is projected to thaw substantially within the 21st century.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 985 
KW  - northern seward peninsula
KW  - deep permafrost carbon
KW  - Laptev Sea region
KW  - Arctic Siberia
KW  - climate change
KW  - gas production
KW  - Lena delta
KW  - soils
KW  - release
KW  - tundra
Y1  - 2020
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/44625
UR  - https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-446250
SN  - 1866-8372
IS  - 20
SP  - 6033
EP  - 6048
ER  -