{"NOAAStudyId":"6199","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-6199.xml","doi":null,"earliestYearBP":6450,"earliestYearCE":-4500,"entryId":"noaa-lake-6199","funding":[],"investigators":"McKay, N.P.; Kaufman, D.S.","mostRecentYearBP":-50,"mostRecentYearCE":2000,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/6199","originalSource":null,"publication":[{"abstract":"Evidence from lake sediments and glacier forefields from two hydrologically isolated lake basins is used to reconstruct Holocene glacier and climate history at Hallet and Greyling Lakes in the central Chugach Mountains of south-central Alaska.  Glacial landform mapping, lichenometry, and equilibrium-line altitude reconstructions, along with changes in sedimentary biogenic-silica content, bulk density, and grain-size distribution indicate a dynamic history of Holocene climate variability.  The evidence suggests a warm early Holocene from 10 to 6 ka, followed by the onset of Neoglaciation in the two drainage basins, beginning between 4.5 and 4.0 ka. During the past 2 ka, the glacial landforms and lacustrine sediments from the two valleys record a remarkably similar history of glaciation, with two primary advances, one during the first millennium AD, from ~500 to 800 AD, and the second during the Little Ice Age (LIA) from ~1400 to 1900 AD.  During the LIA, the reconstructed equilibrium-line altitude in the region was no more than 83-44m (n = 21) lower than the modern, which is based on the extent of glaciers during 1978. Differences between the summer temperature inferred from the biogenic-silica content and the evidence for glacial advances and retreats suggest a period of increased winter precipitation from 1300 to 1500 AD, and reduced winter precipitation from 1800 to 1900 AD, likely associated with variability in the strength of the Aleutian Low.","author":{"name":"McKay, N.P. and D.S. Kaufman."},"citation":"McKay, N.P. and D.S. Kaufman. 2009. Holocene climate and glacier variability at Hallet and Greyling Lakes, \r\nChugach Mountains, south-central Alaska. Journal of Paleolimnology, 41(1), 143-159. doi: 10.1007/s10933-008-9260-0 ","edition":null,"identifier":{"id":"10.1007/s10933-008-9260-0 ","type":"doi","url":"http://dx.doi.org/10.1007/s10933-008-9260-0 "},"issue":"1","journal":"Journal of Paleolimnology","pages":"143-159","pubRank":"1","pubYear":2009,"reportNumber":null,"title":"Holocene climate and glacier variability at Hallet and Greyling Lakes, \r\nChugach Mountains, south-central Alaska","type":"publication","volume":"41"}],"reconstruction":"N","scienceKeywords":["PAGES Arctic 2k","PAGES 2k Network"],"site":[{"NOAASiteId":"20674","geo":{"geoType":"Feature","geometry":{"coordinates":["61.5","-146.2"],"type":"POINT"},"properties":{"easternmostLongitude":"-146.2","maxElevationMeters":"1128","minElevationMeters":"1128","northernmostLatitude":"61.5","southernmostLatitude":"61.5","westernmostLongitude":"-146.2"}},"locationName":"Continent>North America>United States Of America>Alaska","mappable":"Y","paleoData":[{"NOAADataTableId":"9519","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>geochemistry"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/chugach2008.txt","linkText":"chugach2008.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>bulk geological material>sediment>dry sediment","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"gram per cubic centimeter","cvWhat":"physical property>density"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"weight percent","cvWhat":"biological material>bulk biological material>organic matter"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"milligram per gram","cvWhat":"chemical composition>compound>inorganic compound>silicon dioxide>biogenic silica"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>geochemistry"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/chugach2008.xls","linkText":"chugach2008.xls","urlDescription":"Data","variables":[]}],"dataTableName":"Hallet Lake Core HALLET","dataTableNotes":null,"earliestYear":6450,"earliestYearBP":6450,"earliestYearCE":-4500,"mostRecentYear":-50,"mostRecentYearBP":-50,"mostRecentYearCE":2000,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Hallet Lake"}],"studyCode":null,"studyName":"Chugach Range, Alaska 6,500 Year Sediment Data, Hallet and Greyling Lakes","studyNotes":"High resolution organic matter, biogenic silica, and dry bulk density data from Hallet and Greyling Lakes, Chugach Range, South Central Alaska. ","version":"1.0","xmlId":"2163"}