noaa-lake-6202 Mica Lake, Alaska 9,000 Year Diatom Isotope Data Schiff, C.J.; Kaufman, D.S.; Wolfe, A.P.; Dodd, J.; Sharp, Z. Mica Lake, Alaska 9,000 Year Diatom Isotope Data 2008-11-01 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/6202 Investigator C.J. Schiff Investigator D.S. Kaufman Investigator A.P. Wolfe Investigator J. Dodd Investigator Z. Sharp earth science paleoclimate paleolimnology delta 18O,diatom,null,per mil,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology depth,null,null,meter,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology biogenic silica,sediment,null,percent,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology organic matter,sediment,null,percent,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 oxygen isotopes geoscientificInformation PAGES 2k Network PAGES Arctic 2k 9454 cal yr BP -44 cal yr BP Complete 60.95 60.95 -148.15 -148.15 3 3 Continent North America United States Of America Alaska Mica Lake>LATITUDE 60.95>LONGITUDE -148.15 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

325 Broadway, E/NE31

Boulder CO 80305-3328 USA online ASCII Schiff, C.J., D.S. Kaufman, A.P. Wolfe, J. Dodd, and Z. Sharp 2009 Journal of Paleolimnology 41 1 189-208 10.1007/s10933-008-9261-z

The oxygen isotope ratios of diatoms (d18Odiatom), and the oxygen and hydrogen isotope ratios of lake water (dW) of lakes in south Alaska provide insight into past changes in atmospheric circulation. Lake water was collected from 31 lakes along an elevation transect and diatoms were isolated from lake sediment from one lake (Mica Lake) in south Alaska. In general, dW values from coastal lakes overlap the global meteoric water line (GMWL). dW values from interior lakes do not lie on the GMWL; they fall on a local evaporation line trajectory suggesting source isotopes are depleted with respect to maritime lakes. Sediment cores were recovered from 58 m depth in Mica Lake (60.96N, 148.15W; 100 m asl), an evaporation-insensitive lake in the western Prince William Sound. Thirteen calibrated 14C ages on terrestrial macrofossil samples were used to construct an age-depth model for core MC-2, which spans 9910 cal years. Diatoms from 46, 0.5-cm-thick samples were isolated and analyzed for their oxygen isotope ratios. The analyses employed a newly designed, stepwise fluorination technique, which uses a CO2 laser-ablation system, coupled to a mass spectrometer, and has an external reproducibility of 0.2%. d18Odiatom values from Mica Lake sediment range between 25.2 and 29.8%. d18Odiatom values are relatively uniform between 9.6 and 2.6 ka, but exhibit a four-fold increase in variability since 2.6 ka. High-resolution sampling and analyses of the top 100 cm of our lake cores suggest large climate variability during the last 2000 years. The 20th century shows a +4.0% increase of d18Odiatom values. Shifts of d18Odiatom values are likely not related to changes in diatom taxa or dissolution effects. Late Holocene excursions to lower d18Odiatom values suggest a reduction of south-to-north storm trajectories delivered by meridional flow, which likely corresponds to prolonged intervals when the Aleutian Low pressure system weakened. Comparisons with isotope records of precipitation (dP) from the region support the storm-track hypothesis, and add to evidence for variability in North Pacific atmospheric circulation during the Holocene. STUDY NOTES: d18O diatom, biogenic silica, and organic matter from Mica Lake, Alaska, USA

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/mica2008.xls GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/mica2008.txt USA/NOAA DIF Version 9.8.4 2019-03-27 2019-03-27