Quality and Distribution of Frozen Organic Matter (Old, Deep, Fossil Carbon) in Siberian Permafrost EGU2013-12417 Lutz Schirrmeister (1), Jens Strauss (1), Sebastian Wetterich (1), Guido Grosse (2), and Pier Paul Overduin (1) (1) Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Dept. of Periglacial Research, Potsdam, Germany ([email protected]), (2) Geophysical Institute, Permafrost Laboratory, University of Alaska Fairbanks, Fairbanks, USA Thermokarst Study sites of permafrost archives in NE Siberia with fossil OM data sets + 40 depression Active layer Introduction Holocene cover Western Laptev Sea: Thermokarst lake Ÿ + 30 Since 1998, northeast Siberian permafrost sequences have been analyzed as frozen paleoenvironmental archives of the last (1) Cape Mamontov Klyk Weichselian ? Lena Delta: ? Glacial ~200,000 years (joint Russian-German science cooperation “SYSTEM LAPTEV SEA”). Organic matter (OM) properties were used as an + 20 Talik ? (2) Turakh Sise Island, (3) Ebe Sise Island (Nagym), ? important paleo proxy + 10 ? Dmitry (4) Khardang Island, (5) Kurungnakh Sise Island Eemian Laptev Interglacial ŸThis study summarizes regional datasets on the quality and quantity of fossil OM in permafrost sequences of NE Siberia: 11 Central Laptev Sea: Strait ] 0 . l . ? s Saalian à 1 . to show the permafrost carbon pool heterogeneity related to paleoenvironmental dynamics, and 9 (6) Bykovsky Peninsula, (7) Muostakh Island a glacial ? Talik ? m 12 13 14 [ - 10 ? 10 t Plant cover h New Siberian Archipelago: à 15 g to improved estimations of permafrost organic carbon stocks. 3 i Tertiary e 4 8 17 (8) Stolbovoy Island, (9) Bel’kovsky Island, (10) Kotel’ny Island (Cape h Permafrost table • OM distribution in the upper permafrost zone up to 100 m depth in the Northeastern Siberian Arctic indicates considerable variability of 2 16 - 20 Anisii), (11) Kotel’ny Island (Khomurganakh River), (12) Bunge Land (low Ice wedges 5 18 19 Cretaceous OM between different stratigraphical units, between same stratigraphical units at different study sites, and even within stratigraphic 6 terrace), (13) Bunge Land (high terrace), (14) Novaya Sibir Island, (15) - 30 basement 7 Ice casts rocks units at the same site. 21 Maly Lyakhovsky Island - 40 Dmitry Laptev Strait: Early Weichselian (100 to 60 ka) and Lategalcial (15 to 10 ka) and Unfrozen marine Absolute TOC TIC C/N 13C 22 pre Eemia (> 130 ka) flood plain deposits Holocene deposits (< 10 ka) deposits (< 5ka) NW SE ice content (16) Bol’shoy Lyakhovsky Island (Vankina river mouth), l Yedoma - a o y n [%] [wt%] [wt%] [VPDB, ‰] 20 Eemian thermokarst deposits Late Weichselian ice-rich deposits Unfrozen lake e m o l i 35 r l s e ) a (130 to 110 ka) (25 to 15 ka) deposits (< 10 ka) . o (17) Bol’shoy Lyakhovsky Island (Zimov’e river mouth), h v l r . 30 0 50 100 T 0 10 20 0 5 10 0 20 40 -32 -28 -24 e s Thermokarst . 25 Thermokarst Middle Weichselian ice-rich deposits a depression depression 20 12 (18) Cape Svyatoy Nos, (19) Oyogos Yar coast Eemian taberites with numerous peat inclusion Talik zone m (alas) ( (alas) Holocene polygonal cover t 15 (60 to 25 ka) h Zimov'e River g 10 in thermokarst depression i Indigirka-Kolyma lowland: IV IV valley Tertiary sands e 5 Saalian ice-rich deposits Bedrock (granite,limestone, h IIa ] . 10 (200 to 150 ka) sandstone) with coal 0 l . (20) Duvanny Yar (Lower Kolyma R. ). s 0 500 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 . a General scheme of the stratigraphical segments of the permafrost zone, and Distance (m) m Late Glacial / Early Holocene [ (21) Kytalyk (Berelekh R.), (22) Pokhodsk (Kolyma Delta) Middle Weichselian ice-rich deposits Peat in the modern Ice wedges 8 Eemian thermokarst deposits t several components of arctic periglacial landscapes with numerous peat inclusion flood plain of different h thermokarst lake deposits g generations i Saalian ice-rich deposits Early Weichselian flood plain deposits Holocene deposits e absolute H 6 ice content (wt%) TOC (wt%) TIC (wt%) C/N 13 Periglacial reworked Cd (‰ vs VPDB) Pre Eemian flood plain deposits Taberal deposits weathering crust 0 20 40 60 80 100 0.01 0.1 1 10 0 2 4 6 8 0 10 20 30 40 -32 -30 -28 -26 -24 -22 Taberite formed during Conclusion 4 Weichselian to Holocene Holocene thermo- 44.2 ± 9.0 5.3 ± 4.9 0.2 ± 0.2 11.8 ± 3.2 -27.63 ± 0.87 Scheme of stratigraphical units from Bolshoy Lyakhovsky Island (site 17), Dmitry erosional valley n = 22 n = 52 n = 22 n = 50 n = 52 Ÿ 28 transition Carbon contents, OM qualities and decomposition Late Glacial to 44.4 ± 16.0 5.9 ± 9.0 0.2 ± 0.3 10.0 ± 5.4 -27.93 ± 1.33 Laptev Strait Holocene n = 67 n = 148 n = 114 n = 133 n = 139 thermokarst degrees are highly variable and connected to changing Holocene cover 47.4 ± 14.6 10.9 ± 12.2 0.6 ± 0.6 14.9 ± 5.8 -27.98 ± 1.320 26 n = 20 n = 50 n = 37 n = 42 n = 49 Taberites 28.8 ± 4.8 2.7 ± 1.4 0.4 ± 0.1 7.3 ± 3.4 -29.47 ± 1.55 paleoenvironmental conditions Methods n = 4 n = 9 n = 9 n = 9 n = 9 Late Weichselian 38.3 ± 12.5 2.2 ± 0.9 0.4 ± 0.2 9.3.0 ± 2.3 -25.58 ± 0.70 à 24 Ice Complex n = 66 n = 109 n = 94 n = 112 n = 111 Interglacial & interstadial periods: High TOC contents, ] . l . Middle Weichselian 13 Ice content – gravimetrically measured s 40.3 ± 12.8 3.7 ± 4.2 0.4 ± 0.5 10.6 ± 5.2 -26.38 ± 1.26 . Ice Complex n = 234 n = 289 n = 311 n = 338 a Middle Weichselian n = 359 high C/N, low δ C → less-decomposed OM m Early to Late [ 22.4 ± 11.3 0.4 ± 1.3 0.1 ± 0.1 8.8 ± 8.8 -25.70 ± 1.31 22 Ice Comlex deposits Weichselian → Ice-rich (>50 %), ice-bearing (25-50 %), ice-poor (< 25%) t n = 313 n = 426 n = 352 n = 79 n = 99 fluvial deposits h g accumulated under wet, anaerobic soil conditions. i Eemian 29.0 ± 8.3 3.1 ± 4.0 0.6 ± 0.9 10.2 ± 3.7 -27.50 ± 0.70 e The south coast of Bolshoy Lyakhovsky Island thermokarst → Syncryogenic formation, thawing & refreezing (taberite) H n = 37 n = 75 n = 61 n = 37 n = 36 20 lake deposits à Glacial & stadial periods: Less variable, low TOC, low Pre Eemian 32.6 ± 8.3 1.0 ± 0.7 0.3 ± 0.1 6.5 ± 5.0 -25.05 ± 0.29 → Total mass balance calculation, bulk density estimation floodplain n = 23 n = 119 n = 15 n = 16 n = 18 13 Lateglacial to Holocene Middle Weichselian Ice Late Saalian 58.7 ± 20.1 6.2 ± 4.1 1,82 ± 3.0 14.2 ± 4.8 -27.89 ± 1.03 C/N, high δ C values → stable environments with 18 ice-rich deposits n = 20 n = 14 n = 9 n = 14 n = 14 thermokarst basins (lacustrine Complex deposits Q1 Q3 Box plot graph displays the minimum, maximum, median, and min max reduced bioproductivity and stronger OM lower quartile and upper quartile TC, TN, TOC - CNS analyzer (Elementar Vario EL III) median 16 polygonal mires) decomposition under dryer, aerobic soil ] . 10 Stratigraphical classification of permafrost deposits by organic matter signatures, l TOC → Variations in OM accumulation and degradation . s . Schirrmeister et al. (2011) a conditions. Early Weichselian m TOC/TN → Decomposition degree, microbial activities [ 8 alluvial deposits t Ÿ h OM release to the ocean, lakes, rivers and the g Total i Ice Content Bulk Carbon → Low ratios: strongly decomposed; e Stratigraphical [wt%] Density organic inventory SD H 6 Units -3 carbon -3 [g cm ], [wt%], [kg C m ] atmosphere due to permafrost degradation (e.g. high ratios: less decomposed 8 Holocene thermo-erosional valley 44.2 ± 9.0 0.781 5.3 ± 4.9 41.42 40.87 thermokarst, thermal erosion, coastal erosion) and TC-TOC→ TIC; inorganic carbon (e.g. fossil shells) ] . 6 l . microbial decomposition. s Eemian Holocene thermokarst 44.4 ± 16.0 0.775 6.9 ± 9.0 53.51 77.22 . a thermokarst lake deposits m Ÿ [ 4 The landscape average is likely about 30 % lower than 13 t Holocene cover 47.4 ± 14.5 0.686 10.9 ± 12.9 74.73 96.26 h g d C (TOC) - Finnigan DELTA S mass spectrometer i e H previously published permafrost carbon inventories → OM origin (marine, terrestrial; subaerial/aquatic) 2 Taberite formed Taberites 28.8 ± 4.8 1.242 2.7 ± 1.4 33.55 17.82 during Saalian to ŸStill large uncertainties in carbon estimations/ Eemian transition Late Weichselian 38.3 ± 12.5 0.958 2.2 ± 0.9 21.08 11.92 → Composition of plant material 0 Ice Complex 8 calculations. Middle Weichselian → Isotopic fractionation during carbon metabolism Pre-Eemian Ice Complex 40.5 ± 12.8 0.892 3.7 ± 4.1 33.23 40.07 à alluvial deposits Detailed mapping of permafrost deposits especially 13 13 ] . 6 l . → Decomposition degree (low d C less, high d C strong) s . Early to Middle Weichselian a fluvial deposits 22.4 ± 11.3 1.434 0.5 ± 1.4 7.17 18.72 of Ice Complex (Yedoma-type) and thermokarst m [ 4 t h deposits (Alas-type), their distribution and thickness g Late Saalian Eemian lake deposits 29 ± 8.3 1.236 3.2 ± 4.2 39.57 50.10 i e H 2 Ice Complex deposits are essential for OM pool estimation.