noaa-icecore-17820 GISP2 Ice Core Stratigraphy Alley, R.B.; Shuman, C.A.; Meese, D.A.; Gow, A.J.; Taylor, K.C.; Cuffey, K.M.; Fitzpatrick, J.J.; Grootes, P.M.; Zielinski, G.A.; Ram, M.; Spinelli, G.; Elder, B. GISP2 Ice Core Stratigraphy 1997-11-30 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/17820 Investigator R.B. Alley Investigator C.A. Shuman Investigator D.A. Meese Investigator A.J. Gow Investigator K.C. Taylor Investigator K.M. Cuffey Investigator J.J. Fitzpatrick Investigator P.M. Grootes Investigator G.A. Zielinski Investigator M. Ram Investigator G. Spinelli Investigator B. Elder earth science paleoclimate ice cores ice age,null,null,year Common Era,null,ice cores,null,null,N,null earth science paleoclimate ice cores notes,null,null,null,null,ice cores,null,null,N,accumulation rate/layer thickness earth science paleoclimate ice cores depth,null,null,meter,null,ice cores,null,null,N,based on ECM earth science paleoclimate ice cores depth,null,null,meter,null,ice cores,null,null,N,based on visual strat earth science paleoclimate ice cores layer thickness,bulk ice,null,meter,null,ice cores,null,null,N,null earth science paleoclimate ice cores ice age,null,null,calendar year before present,null,ice cores,null,null,N,null earth science paleoclimate ice cores density,bulk ice,null,gram per cubic centimeter,null,ice cores,null,null,N,null earth science paleoclimate ice cores notes,null,null,null,null,ice cores,null,null,N,null earth science paleoclimate ice cores accumulation rate,bulk ice,null,meter per year,null,ice cores,null,null,N,null earth science paleoclimate ice cores depth,null,null,meter,null,ice cores,null,null,N,null earth science paleoclimate ice cores layer thickness,bulk ice,null,meter,null,ice cores,null,null,N,water equivalent earth science paleoclimate ice core physical properties geoscientificInformation 50000 cal yr BP 0 cal yr BP Complete 72.6 72.6 -38.5 -38.5 3200 3200 Continent North America Greenland GISP2>LATITUDE 72.6>LONGITUDE -38.5 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 R. B. Alley, C. A. Shuman, D. A. Meese, A. J. Gow, K. C. Taylor, K. M. Cuffey, J. J. Fitzpatrick, P. M. Grootes, G. A. Zielinski, M. Ram, G. Spinelli, B. Elder 1997 Journal of Geophysical Research: Oceans 102 C12 26367-26381 10.1029/96JC03837 http://onlinelibrary.wiley.com/enhanced/doi/10.1029/96JC03837/

Annual layers are visible in the Greenland Ice Sheet Project 2 ice core from central Greenland, allowing rapid dating of the core. Changes in bubble and grain structure caused by near-surface, primarily summertime formation of hoar complexes provide the main visible annual marker in the Holocene, and changes in "cloudiness" of the ice correlated with dustiness mark Wisconsinan annual cycles; both markers are evident and have been intercalibrated in early Holocene ice. Layer counts are reproducible between different workers and for one worker at different times, with 1% error over century-length times in the Holocene. Reproducibility is typically 5% in Wisconsinan ice-age ice and decreases with increasing age and depth. Cumulative ages from visible stratigraphy are not significantly different from independent ages of prominent events for ice older than the historical record and younger than approximately 50,000 years. Visible observations are not greatly degraded by "brittle ice" or many other core-quality problems, allowing construction of long, consistently sampled time series. High accuracy requires careful study of the core by dedicated observers. STUDY NOTES: Depths of mid-summer as determined separately from ECM and visual stratigraphy in the GISP2-D ice core. Also given are calculated layer thicknesses (true and ice equivalent) and calculated accumulation rates, all in meters.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/physical/visual.txt Data File; GISP2 Visual Stratigraphy GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/physical/strat.txt Data File; GISP2 Stratigraphy USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11