noaa-lake-23290 Loon Lake, Alaska 3000 Year Geochemical Data Chipman, M.L.; Hu, F.S. Loon Lake, Alaska 3000 Year Geochemical Data 2018-01-04 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/23290 Investigator M.L. Chipman Investigator F.S. Hu earth science paleoclimate paleolimnology age at sample end,null,null,calendar year before present,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology depth at sample start,null,null,centimeter,null,paleolimnology,null,null,N,null earth science paleoclimate fire history|paleolimnology charcoal,wet sediment,null,count,null,fire history|paleolimnology,null,null,N,> 120 um earth science paleoclimate paleolimnology volume magnetic susceptibility,sediment,null,dimensionless (SI system),null,paleolimnology,null,magnetic susceptibility measurement with single sample sensor,N,x10-6 earth science paleoclimate paleolimnology strontium,sediment,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second earth science paleoclimate paleolimnology silicon,sediment,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second earth science paleoclimate paleolimnology calcium/strontium,sediment,null,dimensionless,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,ratio earth science paleoclimate paleolimnology iron,soil,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second; soil samples from shoreline retrogressive thaw slumps earth science paleoclimate fire history|paleolimnology depth at sample start,null,null,centimeter,null,fire history|paleolimnology,null,null,N,null earth science paleoclimate paleolimnology calcium carbonate,sediment,null,percent,null,paleolimnology,null,loss on ignition,N,LOI at 950C x (100/44) earth science paleoclimate paleolimnology rubidium,soil,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second; soil samples from shoreline retrogressive thaw slumps earth science paleoclimate paleolimnology silicon,soil,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second; soil samples from shoreline retrogressive thaw slumps earth science paleoclimate paleolimnology calcium/strontium,soil,null,dimensionless,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,soil samples from shoreline retrogressive thaw slumps earth science paleoclimate fire history|paleolimnology depth at sample end,null,null,centimeter,null,fire history|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 density,sediment,null,gram per cubic centimeter,null,paleolimnology,null,loss on ignition,N,Bulk Density LOI at 120C earth science paleoclimate paleolimnology mass magnetic susceptibility,sediment,null,cubic centimeter per gram,null,paleolimnology,null,magnetic susceptibility measurement with single sample sensor,N,null earth science paleoclimate paleolimnology iron,sediment,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second earth science paleoclimate paleolimnology sample identification,null,null,null,null,paleolimnology,null,null,C,Lake name earth science paleoclimate paleolimnology sample identification,null,null,null,null,paleolimnology,null,null,C,ID code for RTS feature earth science paleoclimate fire history|paleolimnology age at sample end,null,null,calendar year before present,null,fire history|paleolimnology,null,null,N,null earth science paleoclimate paleolimnology age at sample start,null,null,calendar year before present,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology organic matter,sediment,null,percent,null,paleolimnology,null,loss on ignition,N,LOI at 550 C earth science paleoclimate paleolimnology rubidium,sediment,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second earth science paleoclimate fire history|paleolimnology age at sample start,null,null,calendar year before present,null,fire history|paleolimnology,null,null,N,null earth science paleoclimate paleolimnology potassium,sediment,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second earth science paleoclimate paleolimnology notes,null,null,null,null,paleolimnology,null,null,C,General sample location in RTS earth science paleoclimate paleolimnology notes,null,null,null,null,paleolimnology,null,null,C,Additonal sample description earth science paleoclimate fire history|paleolimnology volume,wet sediment,null,cubic centimeter,null,fire history|paleolimnology,null,null,N,used for charcoal counts earth science paleoclimate paleolimnology calcium,sediment,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second earth science paleoclimate paleolimnology titanium,sediment,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second earth science paleoclimate paleolimnology calcium/potassium,sediment,null,dimensionless,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,ratio earth science paleoclimate paleolimnology calcium,soil,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second; soil samples from shoreline retrogressive thaw slumps earth science paleoclimate paleolimnology titanium,soil,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second; soil samples from shoreline retrogressive thaw slumps earth science paleoclimate paleolimnology potassium,soil,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second; soil samples from shoreline retrogressive thaw slumps earth science paleoclimate paleolimnology strontium,soil,null,count per second,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second; soil samples from shoreline retrogressive thaw slumps earth science paleoclimate paleolimnology calcium/potassium,soil,null,dimensionless,null,paleolimnology,null,x-ray fluorescence spectroscopy,N,normalized counts per second; soil samples from shoreline retrogressive thaw slumps earth science paleoclimate paleolimnology magnetic susceptibility earth science paleoclimate paleolimnology geochemistry geoscientificInformation 3003 cal yr BP -64 cal yr BP Complete 67.929269 67.929269 -161.966944 -161.966944 Continent North America United States Of America Alaska Loon Lake Alaska>LATITUDE 67.929269>LONGITUDE -161.966944 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Chipman, M.L. and Hu, F.S. 2017 Journal of Geophysical Research: Biogeosciences 10.1002/2017JG004027 http://onlinelibrary.wiley.com/doi/10.1002/2017JG004027/abstract

Amplified Arctic warming may facilitate novel tundra disturbance regimes, as suggested by recent increases in the rate and extent of thermoerosion and fires in some tundra areas. Thermoerosion and wildfire can exacerbate warming by releasing large permafrost carbon stocks, and interactions between disturbance regimes can lead to complex ecosystem feedbacks. We conducted geochemical and charcoal analyses of lake sediments from an Alaskan lake to identify thermoerosion and fire events over the past 3,000 years. Thermoerosion was inferred from lake sediments in the context of modern soil data from retrogressive thaw slumps (RTS). Magnetic susceptibility (MS), Ca:K, and Ca:Sr increased with depth in modern RTS soils and were higher on recently exposed than older slump surfaces. Peaks in bulk density, % CaCO3, Ca:K, Ca:Sr, and MS values in the sediments suggest at least 18 thermoerosion events in the Loon Lake watershed over the past 3,000 years. Charcoal analysis identifies 22 fires over the same period at this site. Temporal variability in these records suggests climate-driven responses of both thermoerosion and fire disturbance regimes, with fewer RTS episodes and fire events during the Little Ice Age than the Medieval Climate Anomaly. Moreover, RTS activity lagged behind catchment fires by 20-30 years (>90% confidence interval), implying that fires facilitated thermoerosion on decadal time scales, possibly because of prolonged active-layer deepening following fire and postfire proliferation of insulative shrub cover. These results highlight the potential for complex interactions between climate, vegetation, and tundra disturbance in response to ongoing warming. STUDY NOTES: Geochemical data from Loon Lake, Noatak National Preserve, Alaska.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/loon2018loi.txt NOAA Template File; Loon Lake LOI Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/loon2018xrf.txt NOAA Template File; Loon Lake Sediment XRF Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/loon2018soilxrf.txt NOAA Template File; Loon Lake Soil XRF Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/loon2018charcoal.txt NOAA Template File; Loon Lake Charcoal Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/loon2018ms.txt NOAA Template File; Loon Lake Magnetic Susceptibility Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11