{"NOAAStudyId":"6196","contactInfo":{"address":"325 Broadway, E/NE31","city":"Boulder","constraints":"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.","country":"USA","dataCenterUrl":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data","email":"paleo@noaa.gov","fax":"303-497-6513","longName":"National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce ","phone":"303-497-6280","postalCode":"80305-3328","shortName":"DOC/NOAA/NESDIS/NCEI","state":"CO","type":"CONTACT INFORMATION"},"contributionDate":"2008-11-01","dataPublisher":"NOAA","dataType":"PALEOLIMNOLOGY","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/lake","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-lake-6196.xml","doi":null,"earliestYearBP":2085,"earliestYearCE":-135,"entryId":"noaa-lake-6196","funding":[],"investigators":"Geirsdóttir, A.; Miller, G.H.; Thordarson, T.; Olafsdottir, K.B.","mostRecentYearBP":-53,"mostRecentYearCE":2003,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/6196","originalSource":null,"publication":[{"abstract":"The sediment fill of Haukadalsvatn, a lake in northwest Iceland, preserves a record of environmental change since deglaciation, 13 ka ago. The rapid sedimentation rate over the past 2 ka (ca. 4 m ka-1) provides a high-resolution archive of late Holocene environmental change. Physical and chemical environmental proxies extracted from cores from the Haukadalsvatn sediment fill provide a reconstruction of sub-decadal-scale climate variability in Iceland over the past 2 ka. Over this interval biogenic silica (BSi) reflects warm April-May temperatures, whereas total organic carbon (TOC) peaks represent an increased flux of carbon to the lake from eolian-derived soil erosion following periods of cold summers accompanied by dry, windy winters. The proxy-based temperature reconstructions show a broad interval of warmth through Medieval times, but this warmth is punctuated by multi-decadal cold intervals. The transition into the Little Ice Age occurred in two steps, with initial summer cooling 1250-1300 AD, and a more severe drop in summer temperatures between 1450 and 1500 AD; both are periods of severe explosive volcanism. Multi-decadal patterns of cold and warm conditions have some characteristics of a North Atlantic Oscillation (NAO)-like signal, but instrumental records and proxy-based reconstructions of the NAO index contain little power in the frequencies most strongly expressed in our data set. Although severe soil erosion in Iceland is frequently equated with settlement, our reconstructions indicate that soil erosion began several centuries before settlement, whereas for several centuries after settlement, when summer temperatures were relatively high, there was little or no soil erosion. Only during the transition into and during the Little Ice Age did soil erosion become a major feature of the record.","author":{"name":"Aslaug Geirsdottir, Gifford H. Miller, Thorvaldur Thordarson, Kristin B. Olafsdottir\r\n"},"citation":"Aslaug Geirsdottir, Gifford H. Miller, Thorvaldur Thordarson, Kristin B. Olafsdottir\r\n. 2009. A 2000 year record of climate variations reconstructed from Haukadalsvatn, west Iceland. Journal of Paleolimnology, 41(1), 95-115. doi: 10.1007/s10933-008-9253-z","edition":null,"identifier":{"id":"10.1007/s10933-008-9253-z","type":"doi","url":"http://dx.doi.org/10.1007/s10933-008-9253-z"},"issue":"1","journal":"Journal of Paleolimnology","pages":"95-115","pubRank":"1","pubYear":2009,"reportNumber":null,"title":"A 2000 year record of climate variations reconstructed from Haukadalsvatn, west Iceland","type":"publication","volume":"41"}],"reconstruction":"N","scienceKeywords":["PAGES Arctic 2k","PAGES 2k Network"],"site":[{"NOAASiteId":"20671","geo":{"geoType":"Feature","geometry":{"coordinates":["65.051","-21.6305"],"type":"POINT"},"properties":{"easternmostLongitude":"-21.6305","maxElevationMeters":"32","minElevationMeters":"32","northernmostLatitude":"65.051","southernmostLatitude":"65.051","westernmostLongitude":"-21.6305"}},"locationName":"Continent>Europe>Northern Europe>Iceland","mappable":"Y","paleoData":[{"NOAADataTableId":"9516","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>geochemistry"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/haukadalsvatn2008.txt","linkText":"haukadalsvatn2008.txt","urlDescription":"Data","variables":[{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"year Common Era","cvWhat":"age variable>age"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":"method of Mortlock and Froelich 1989 with 10% Na2CO3","cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"spectrophotometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"weight percent","cvWhat":"chemical composition>compound>inorganic compound>silicon dioxide>biogenic silica"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"carbon coulometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"weight percent","cvWhat":"chemical composition>element or single-element molecule>carbon>organic carbon"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>geochemistry"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/haukadalsvatn2008.xls","linkText":"haukadalsvatn2008.xls","urlDescription":"Data","variables":[]}],"dataTableName":"Haukadalsvatn Core HAUKADAL","dataTableNotes":null,"earliestYear":2085,"earliestYearBP":2085,"earliestYearCE":-135,"mostRecentYear":-53,"mostRecentYearBP":-53,"mostRecentYearCE":2003,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Haukadalsvatn"}],"studyCode":null,"studyName":"Haukadalsvatn, Iceland 2,000 Year Geochemical Data","studyNotes":"Biogenic silica (BSi) and total organic carbon (TOC) from core GLAD4-HAK03-1B, Haukadalsvatn, West Iceland.","version":"1.0","xmlId":"2144"}