Dune Lake, Alaska 12,000 Year Multiproxy Sediment Data Finney, B.P.; Bigelow, N.H.; Barber, V.A.; Edwards, M.E. Finney, B.P. Bigelow, N.H. Barber, V.A. Edwards, M.E. Arctic PAGES Arctic 2k carbon cycle earth science/paleoclimate/paleolimnology (depth at sample start,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (depth,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (organic matter,sediment,null,percent,null,paleolimnology,null,loss on ignition,N,550 degrees C) earth science/paleoclimate/paleolimnology (sample identification,null,null,null,null,paleolimnology,null,null,C,null) earth science/paleoclimate/paleolimnology (mass,dry sediment,null,gram per square centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (density,dry sediment,null,null,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (delta 13C,sediment,null,per mil VPDB,null,paleolimnology,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/paleolimnology (delta 13C,sediment,null,per mil VPDB,null,paleolimnology,corrected,isotope ratio mass spectrometry,N,corrected for Suess effect) earth science/paleoclimate/paleolimnology (volume magnetic susceptibility,sediment,null,dimensionless (SI system),null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (volume magnetic susceptibility,sediment,null,dimensionless,null,paleolimnology,null,null,N,1/g (SI system)) earth science/paleoclimate/paleolimnology (age,null,null,year Common Era,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (accumulation rate,dry sediment,null,gram per square centimeter per year,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (biogenic silica,sediment,null,milligram per square centimeter per year,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (organic carbon,sediment,null,milligram per square centimeter per year,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (depth at sample end,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (biogenic silica,sediment,null,percent,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (water content,sediment,null,percent,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (biogenic silica,ostracod,null,percent,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (organic carbon,dry sediment,null,percent,null,paleolimnology,null,elemental analysis,N,null) earth science/paleoclimate/paleolimnology (carbon/nitrogen,sediment,null,dimensionless,null,paleolimnology,null,elemental analysis,N,total organic carbon/total nitrogen) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (nitrogen,dry sediment,null,percent,null,paleolimnology,null,elemental analysis,N,null) earth science/paleoclimate/paleolimnology (delta 15N,sediment,null,per mil AIR,null,paleolimnology,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/paleolimnology (organic matter,sediment,null,milligram per square centimeter per year,null,paleolimnology,null,loss on ignition,N,null) earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology (Dune Lake AK>LATITUDE 64.42>LONGITUDE -149.9) Opal, organic C and N contents, and organic d13C and d15N stable isotopes were analyzed on a sedimentary sequence spanning the past ~12,000 years from Dune Lake, a shallow groundwater-fed lake in the boreal forest region of central interior Alaska. The chronology, based on 210Pb and 15 AMS radiocarbon dates on terrestrial materials, indicates that 5 m of biogenic sediment accumulated following dune stabilization at ~10,000 cal yr BP. Previous studies on lake level and pollen were synthesized with these data to assess Holocene changes in hydrogeology and climate. Variability in groundwater level and flux has a strong control on lake level and are negatively correlated with the d13C of organic matter produced within the lake. This relationship results from the input of groundwater with high pCO2 and with dissolved inorganic carbon depleted in 13C, which subsequently affects lake phytoplankton d13C signatures. A rapid rise in lake level between ca. 11,000 and 9,500 cal yr BP coincided with stabilization of the dune field adjacent to the lake and expansion of vegetation around the lake, including white spruce. Organic d13C values are relatively low and constant between about 10,000 and 6,000 cal yr BP, and then steadily increase until about 2,000 cal yr BP, suggesting a pattern of high followed by dropping lake levels generally consistent with results from core-transect studies. Higher-frequency fluctuations of 2–3 ‰ in d13C are common, and suggest variability in aspects of the lake-carbon cycle over multi-decadal timescales. Recent trends in groundwater and lake level, river discharge, and precipitation suggest an important role for wintertime precipitation in the regional groundwater system. The unusual hydrology of this system relative to most other lakes studied for paleoclimate in this region provides a novel insight into different seasonal aspects of Alaskan paleoclimatology. The record is consistent with a general long-term decrease in wintertime precipitation, possibly accompanied by an increase in permafrost extent, over the Holocene. STUDY NOTES: Multiproxy sediment data from Dune Lake, Alaska, for the past 12,000 years. Dune Lake is a shallow, closed basin, groundwater-fed lake located in the boreal forest of central Alaska. Paleoenvironmental proxies measured include Opal, organic C and N contents, and organic d13C and d15N stable isotopes. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Finney, B.P. Investigator : Bigelow, N.H. Investigator : Barber, V.A. Investigator : Edwards, M.E. 2012-06-30 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/13076 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/dune2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/dune2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/dune2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/dune2012.txt English https://www.ncdc.noaa.gov/paleo/study/13076 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/dune2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/dune2012.txt Finney, B.P., N.H. Bigelow, V.A. Barber, and M.E. Edwards. 2012. Holocene climate change and carbon cycling in a groundwater-fed, boreal forest lake: Dune Lake, Alaska. Journal of Paleolimnology, Vol. 48, No. 1, June 2012, pp. 43-54. DOI: 10.1007/s10933-012-9617-2 START YEAR: 11326 cal yr BP * END YEAR: -42 cal yr BP -149.9 64.42 -149.9 64.42