noaa-lake-6199 Chugach Range, Alaska 6,500 Year Sediment Data, Hallet and Greyling Lakes McKay, N.P.; Kaufman, D.S. Chugach Range, Alaska 6,500 Year Sediment Data, Hallet and Greyling Lakes 2008-11-01 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/6199 Investigator N.P. McKay Investigator D.S. Kaufman earth science paleoclimate paleolimnology organic matter,sediment,null,weight percent,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology density,dry sediment,null,gram per cubic centimeter,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology biogenic silica,sediment,null,milligram per gram,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology age,null,null,calendar year before present,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology geochemistry geoscientificInformation PAGES 2k Network PAGES Arctic 2k 6450 cal yr BP -50 cal yr BP Complete 61.5 61.5 -146.2 -146.2 1128 1128 Continent North America United States Of America Alaska Hallet Lake>LATITUDE 61.5>LONGITUDE -146.2 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 McKay, N.P. and D.S. Kaufman. 2009 Journal of Paleolimnology 41 1 143-159 10.1007/s10933-008-9260-0

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. STUDY NOTES: High resolution organic matter, biogenic silica, and dry bulk density data from Hallet and Greyling Lakes, Chugach Range, South Central Alaska.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/chugach2008.xls GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/chugach2008.txt USA/NOAA DIF Version 9.8.4 2019-03-27 2019-03-27