{"NOAAStudyId":"5475","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":"2000-01-01","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-5475.xml","doi":null,"earliestYearBP":11910,"earliestYearCE":-9960,"entryId":"noaa-lake-5475","funding":[],"investigators":"Hu, F.S.","mostRecentYearBP":7480,"mostRecentYearCE":-5530,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/5475","originalSource":null,"publication":[{"abstract":"Recent studies of the Greenland ice cores have offered many insights into Holocene climatic dynamics at decadal to century timescales. Despite the abundance of continental records of Holocene climate, few have sufficient chronological control and sampling resolution to compare with the Greenland findings. Butannually laminated sediments (varves) from lakes can provide high-resolution continental palaeoclimate data with secure chronologies. Here we present analyses of varved sediments from Deep Lake in Minnesota, USA. Trends in the stable oxygen-isotope composition of the sedimentary carbonate indicate a pronounced climate cooling from 8.9 to 8.3 kyr before present, probably characterized by increased outbreaks of polar air, decreased precipitation temperatures, and a higher fraction of the annual precipitation falling as snow. The abrupt onset of this climate reversal, over several decades, was probably caused by a reorganization of atmospheric circulation and cooling of the Arctic airmass in summer that resulted from the final collapse of the Laurentide ice near Hudson Bay and the discharge of icebergs from the Quebec and Keewatin centres into the Tyrell Sea. The timing and duration of this climate reversal suggest that it is distinct from the prominent widespread cold snap that occurred 8,200 years ago in Greenland and other regions. No shifts in the oxygen-isotope composition of sediment carbonate occurred at 8.2 kyr before present at Deep Lake, but varve thickness increased dramatically, probably as a result of increased deposition of aeolian dust. Taken together, our data suggest that two separate regional-scale climate reversals occurred between 9,000 and 8,000 years ago, and that they were driven by different mechanisms.","author":null,"citation":"Hu, F.S.. 1999. Abrupt changes in North American climate during early Holocene times. Nature Vol. 400, pp. 437-440","edition":null,"identifier":null,"issue":null,"journal":"Nature","pages":null,"pubRank":"1","pubYear":1999,"reportNumber":null,"title":"Abrupt changes in North American climate during early Holocene times","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"8927","geo":{"geoType":"Feature","geometry":{"coordinates":["47.68389","-95.39944"],"type":"POINT"},"properties":{"easternmostLongitude":"-95.39944","maxElevationMeters":null,"minElevationMeters":null,"northernmostLatitude":"47.68389","southernmostLatitude":"47.68389","westernmostLongitude":"-95.39944"}},"locationName":"Continent>North America>United States Of America>Minnesota","mappable":"Y","paleoData":[{"NOAADataTableId":"7247","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>age control"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/greatplains/deeplake/deeplake_c14.txt","linkText":"deeplake_c14.txt","urlDescription":"Data","variables":[]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>physical properties","earth science>paleoclimate>paleolimnology>population abundance","earth science>paleoclimate>paleolimnology>oxygen isotopes","earth science>paleoclimate>paleolimnology>age control"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/greatplains/deeplake/deeplake_hu1999.xls","linkText":"deeplake_hu1999.xls","urlDescription":"Data","variables":[]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>oxygen isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/greatplains/deeplake/deeplake_isotopes.txt","linkText":"deeplake_isotopes.txt","urlDescription":"Data","variables":[{"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":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 18O"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>population abundance"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/greatplains/deeplake/deeplake_pollen.txt","linkText":"deeplake_pollen.txt","urlDescription":"Data","variables":[{"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"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>physical properties"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/greatplains/deeplake/deeplake_varves.txt","linkText":"deeplake_varves.txt","urlDescription":"Data","variables":[{"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":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"physical property>length>varve thickness"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>lake level"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/greatplains/deeplake/readme_hu1999.txt","linkText":"readme_hu1999.txt","urlDescription":"Readme","variables":[]}],"dataTableName":"Deep Lake Core DEEPLAKE","dataTableNotes":null,"earliestYear":11910,"earliestYearBP":11910,"earliestYearCE":-9960,"mostRecentYear":7480,"mostRecentYearBP":7480,"mostRecentYearCE":-5530,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Deep Lake"}],"studyCode":null,"studyName":"Deep Lake Minnesota 12,000 Year Sediment Data","studyNotes":"Deep Lake Minnesota Sediment Data, used for Abrupt Holocene Climate Change analysis by Hu et al.","version":"1.0","xmlId":"653"}