Qalluuraq Lake, Alaska 12,000 Year Multiproxy Methane Sediment Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: Please cite original reference when using these data, plus the data file URL and date accessed. NAME OF DATA SET: Qalluuraq Lake, Alaska 12,000 Year Multiproxy Methane Sediment Data LAST UPDATE: 6/2012 (Original receipt by WDC Paleo) CONTRIBUTORS: Wooller, M.J., J.W. Pohlman, B.V. Gaglioti, P. Langdon, M. Jones, K.M. Walter Anthony, K.W. Becker, K.-U. Hinrichs, M. Elvert IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2012-090 WDC PALEO CONTRIBUTION SERIES CITATION: Wooller, M.J., et al. 2012. Qalluuraq Lake, Alaska 12,000 Year Multiproxy Methane Sediment Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2012-090. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Wooller, M.J., J.W. Pohlman, B.V. Gaglioti, P. Langdon, M. Jones, K.M. Walter Anthony, K.W. Becker, K.-U. Hinrichs, and M. Elvert. 2012. Reconstruction of past methane availability in an Arctic Alaska wetland indicates climate influenced methane release during the past ~12,000 years. Journal of Paleolimnology, Vol. 48, No. 1, June 2012, pp. 27-42. DOI: 10.1007/s10933-012-9591-8 ABSTRACT: Atmospheric contributions of methane from Arctic wetlands during the Holocene are dynamic and linked to climate oscillations. However, long-term records linking climate variability to methane availability in Arctic wetlands are lacking. We present a multi-proxy ~12,000 year paleoecological reconstruction of intermittent methane availability from a radiocarbon-dated sediment core (LQ-West) taken from a shallow tundra lake (Qalluuraq Lake) in Arctic Alaska. Specifically, stable carbon isotopic values of photosynthetic biomarkers and methane are utilized to estimate the proportional contribution of methane-derived carbon to lake-sediment-preserved benthic (chironomids) and pelagic (cladocerans) components over the last ~12,000 years. These results were compared to temperature, hydrologic, and habitat reconstructions from the same site using chironomid assemblage data, oxygen isotopes of chironomid head capsules, and radiocarbon ages of plant macrofossils. Cladoceran ephippia from ~4,000 cal year BP sediments have d13C values that range from ~-39 to -31‰, suggesting peak methane carbon assimilation at that time. These low d13C values coincide with an apparent decrease in effective moisture and development of a wetland that included Sphagnum subsecundum. Incorporation of methane-derived carbon by chironomids and cladocerans decreased from ~2,500 to 1,500 cal year BP, coinciding with a temperature decrease. Live-collected chironomids with a radiocarbon age of 1,640 cal year BP, and fossil chironomids from 1,500 cal year BP in the core illustrate that ‘old’ carbon has also contributed to the development of the aquatic ecosystem since ~1,500 cal year BP. The relatively low d13C values of aquatic invertebrates (as low as -40.5‰) provide evidence of methane incorporation by lake invertebrates, and suggest intermittent climate-linked methane release from the lake throughout the Holocene. GEOGRAPHIC REGION: Northwestern North America PERIOD OF RECORD: 12000 YrBP - present FUNDING SOURCES: DATA FILE URLS: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/qalluuraq2012.txt ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/qalluuraq2012.xls DESCRIPTION: Multiproxy sediment data from Qalluuraq Lake, Alaska, for the past 12,000 years. Paleoenvironmental proxies measured include stable isotopic ratios, organic carbon, magnetics, and plant macrofossils. Qalluuraq Lake, Alaska: 70.379°N, 157.348°W, 13m elev. DATA: Wooller et al., 2012 Lake Qalluuraq core (LQ-West) details All core depths given are the bottoms of 1 cm thickness sections of the core. 1. Geochronology AMS laboratory accession Type Depth 14C age error Calib.Age Calibrated range (cal yr BP) (cal yr BP) (cm) (yr BP) (cal yr BP) 2 sigma 2 sigma OS-76261 Graminoid 25 2,830 35 2,958 2,853-3,062 OS-76260 Moss 41 8,430 50 9,420 9,308-9,532 OS-76295 Moss 46* 9,510 35 10,874 10,676-11,071 OS-86085 Moss 48* 9,660 60 10,993 10,779-11,207 OS-86081 Plant macrofossils 49* 9,370 45 10,577 10,441-10,712 Beta-294952 Wood 66 9,690 50 11,010 10,794-11,225 OS-76296 Plant macrofossils 80 10,350 35 12,221 12,055-12,387 OS-76297 Wood 93 10,300 50 12,110 11,833-12,386 OS-66808 Modern chironomid 0 1,740 30 1,638.5 1,562-1,715 OS-86049 Fossil chironomid 9 2,620 50 2,681 2,510-2,852 OS-86050 Fossil chironomid 17 2,680 60 2,822 2,719-2,925 OS-84854 Fossil chironomid 30 2,840 65 2,974 2,789-3,158 OS-87763 Fossil chironomid 66 10,700 170 12,569 12,089-13,048 * = radiocarbon values and depths used to produce a mean age and depth value 2. Plant macrofossil percentages Core depth (cm) 32 45 52 56 60 64 72 Taxon Fontinalis sp. - - - 50 55 50 - Scorpidium scorpioides - 10 18 20 10 30 - Limprichtia revolvens 2 75 60 30 30 - 60 Drepanocladus aduncus - 5 20 - 5 - 10 Warnstorfia exannulata 3 5 - - - - - Sphagnum subsecundum 10 - - - - - - Aulacomnium palustre 1* - - - - - - Mniaceae moss 1* - - - - - 1* Equisetum - 2 2 - - - - graminoid material - 2 - - - 2 - Detrital peat 85 - - - - 20 30 3. Magnetics Core depth (cm) Magnetics 5 1.6 10 2.5 15 2.9 20 3.1 25 2.6 30 2.9 35 3.1 40 3.1 45 2.8 50 2 55 1.5 60 1.8 65 2.3 70 2.6 75 2.7 80 3.9 85 5.1 90 3.6 95 4.8 100 6.8 105 10.8 110 14 115 17.9 120 21.8 125 22.8 130 18.2 135 15.6 140 15.2 145 17 150 23.4 155 30.3 160 33.3 4. TOC and TN data Sediment Sediment Sediment Sediment Sediment Core depth (cm) %N %C (TOC) d15N d13C C:N 1 0.9 11.9 3.2 -26.7 13.4 2 0.7 10.0 3.2 -26.7 13.6 3 1.0 12.9 3.3 -26.8 12.8 4 0.8 10.1 3.3 -26.6 13.0 5 0.7 8.9 3.4 -26.4 12.8 6 0.6 8.5 3.1 -26.2 13.8 7 0.5 7.0 3.2 -26.3 13.1 8 0.6 8.4 3.1 -26.4 13.9 9 0.5 7.2 3.0 -26.4 14.0 10 0.4 5.0 2.6 -26.4 14.5 11 0.5 6.5 3.2 -26.2 13.7 12 0.3 3.6 2.7 -26.9 14.5 13 0.5 6.7 3.1 -26.3 14.1 14 0.3 4.3 2.3 -26.5 14.5 15 0.2 3.0 2.8 -26.6 14.1 16 0.3 4.3 2.8 -26.3 14.2 17 0.2 3.4 2.6 -26.5 15.0 18 0.2 2.1 2.6 -26.6 14.3 19 0.2 2.6 3.0 -26.5 14.4 20 0.2 3.6 3.4 -26.5 15.0 21 0.1 1.9 2.9 -26.6 14.0 22 0.3 4.8 3.3 -26.5 14.9 23 0.3 4.1 3.1 -26.5 15.2 24 0.4 5.4 3.0 -26.3 15.1 25 0.9 13.2 2.6 -26.4 15.5 26 0.9 12.8 2.7 -26.4 15.0 27 0.9 12.8 2.7 -26.1 14.9 28 0.8 11.7 2.7 -26.1 15.1 29 0.9 13.6 2.8 -26.1 15.3 30 0.7 9.9 2.6 -26.2 15.1 31 0.8 11.5 2.8 -25.8 14.7 32 0.8 11.9 3.1 -25.9 14.5 33 1.0 14.4 3.0 -25.9 14.1 34 0.9 12.0 3.2 -25.4 14.0 35 0.3 4.4 3.1 -25.2 14.1 36 0.5 7.0 3.1 -24.9 13.9 37 0.4 5.0 3.2 -24.7 13.8 38 0.3 4.0 3.3 -24.8 13.6 39 0.2 3.1 2.7 -25.4 14.3 40 0.5 6.9 3.5 -24.4 13.1 41 0.5 7.2 3.4 -24.3 14.0 42 0.6 7.9 3.1 -23.1 14.3 43 0.3 4.0 2.5 -24.6 15.6 44 0.3 4.1 3.1 -23.0 15.0 45 0.5 7.9 2.4 -25.1 15.6 46 0.6 8.9 2.5 -25.2 14.5 47 0.6 8.9 2.3 -25.2 15.6 48 0.7 8.2 2.6 -24.8 12.4 49 0.5 7.9 2.7 -25.0 14.6 50 0.8 10.4 2.8 -24.6 12.6 51 0.8 9.3 2.4 -24.4 12.4 52 0.9 8.8 2.5 -24.1 10.1 53 0.7 9.2 2.7 -24.4 12.9 54 0.6 7.1 2.5 -24.1 11.5 55 0.8 10.4 2.8 -24.3 12.7 56 0.6 7.4 2.8 -24.1 12.1 57 0.9 10.8 2.4 -25.0 11.8 58 0.8 10.2 2.5 -24.9 13.1 59 0.5 7.0 2.6 -25.4 13.9 60 0.9 9.9 2.9 -25.1 11.2 61 0.9 11.5 2.2 -25.6 13.5 62 0.9 9.0 2.3 -25.7 10.4 63 0.7 11.0 2.6 -25.7 15.1 64 0.7 10.3 4.1 -25.2 14.2 65 0.5 6.4 4.7 -24.8 13.2 66 0.6 7.8 5.0 -23.5 12.2 67 0.8 8.3 4.9 -23.4 10.3 68 0.7 5.9 5.2 -24.0 9.0 69 0.7 9.1 6.1 -23.9 13.1 70 0.9 11.1 5.9 -24.1 11.9 71 0.9 11.2 6.3 -23.9 12.0 72 0.8 6.7 2.8 -24.9 8.1 73 0.7 7.8 8.0 -24.0 11.8 74 0.8 8.1 6.0 -23.8 9.9 75 0.7 8.2 4.8 -23.4 11.2 76 0.6 7.5 6.7 -24.1 13.2 77 0.6 8.5 6.4 -24.2 13.9 78 0.6 9.3 5.7 -23.0 14.9 79 0.6 9.0 6.0 -23.1 14.9 80 0.4 4.2 4.4 -24.4 12.0 81 0.4 4.9 3.3 -27.0 13.1 99 0.0 0.1 4.2 119 0.0 0.1 4.7 149 0.0 0.1 4.1 5. Chironomid carbon isotopes Note - not trophically adjusted Chironomid Core depth (cm) d13C VPDB 1 -28.8 4 -28.2 8 -31.0 10 -26.9 12 -28.9 13 -26.7 16 -27.2 18 -27.1 20 -26.3 24 -29.5 25 -27.4 28 -29.0 32 -28.1 34 -28.3 36 -26.4 38 -25.9 40 -27.2 44 -24.9 48 -27.2 52 -23.8 56 -26.9 68 -27.8 72 -28.6 73 -26.5 74 -27.6 77 -26.5 80 -26.4 6. Ephippia carbon isotopes Note - not trophically adjusted Ephippea Core depth (cm) d13C VPDB 7 -32.8 8 -30.3 15 -27.6 21 -30.3 23 -31.8 24 -32.4 26 -38.0 27 -38.5 28 -32.9 31 -31.4 32 -30.9 7. Chironomid inferred temp (°C) Chrionomid inferred temp. °C Core depth (cm) CI-T 2 10.91 6 9.467 11 10.639 17 9.288 22 9.979 26 9.894 31 10.282 37 11.488 42 11.394 46 11.05 51 10.011 57 9.288 62 11.21 66 10.397 71 11.692 77 11.342 80 11.128 8. Biomarker carbon isotopes Cholesterol C27 Core depth (cm) d13C VPDB d13C VPDB 1 -33.2 -29.2 4 -31.4 -28.3 8 -32.5 -27.9 12 -31.4 -28.4 16 -30.9 -29.4 24 -29.1 -28.5 28 -29.1 -27.8 32 -31.6 -27.4 36 -29 -26.3 40 -31.8 -28.6 44 -27 -28 48 -32.4 -31.3 52 -29.6 -30.6 56 -29.7 -30.5 68 -30 -29.6 72 -30.2 -31.2 80 -29.9 -31.5 9. Chironomid oxygen isotopes Raw Chironomid Core depth (cm) d18O VSMOW 3 20.0 7 17.7 11 19.1 15 19.7 19 19.4 23 21.7 27 19.8 31 17.2 35 18.4 39 18.7 43 18.8 47 17.9 51 18.2 55 18.9 59 17.1 63 17.9 67 16.7 71 18.1 75 16.0 79 17.6