GISP2 Ice Core Thin Sections Alley, R.B.; Gow, A.J.; Meese, D.A.; Fitzpatrick, J.J.; Waddington, E.D.; Bolzan, J.F. Alley, R.B. Gow, A.J. Meese, D.A. Fitzpatrick, J.J. Waddington, E.D. Bolzan, J.F. earth science/paleoclimate/ice cores (inclination,bulk ice,null,degree,null,ice cores,null,null,N,ice crystal inclination) earth science/paleoclimate/ice cores (sample identification,null,null,null,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (azimuth,bulk ice,null,degree,null,ice cores,null,null,N,ice crystal azimuth) earth science/paleoclimate/ice core (GISP2>LATITUDE 72.6>LONGITUDE -38.5) Flow disturbances have been shown to alter stratigraphic order in the lower part of the ice sheet in central Greenland. Vertical thin sections of the Greenland Ice Sheet Project 2 ice core show that in the lower 30%, the expected c axis-vertical fabric is interrupted by planes of grains ("stripes") with c axes oriented approximately in the dip directions of the planes. Stripe-parallel shear produces small-scale folds. The stripes can be explained qualitatively by a simple nucleation-and-growth model based on the strong anisotropy of ice-crystal deformation. Nucleation probably is sensitive to spatially variable rates of polygonization, producing spatially variable stripe densities. Stripes are modeled to affect the ice viscosity, so variations in stripe density may contribute to viscosity contrasts that might produce larger deformational features and loss of stratigraphic order. STUDY NOTES: Vertical thin sections from the GISP2 core were examined on the Rigsby stage for c-axis orientation. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Alley, R.B. Investigator : Gow, A.J. Investigator : Meese, D.A. Investigator : Fitzpatrick, J.J. Investigator : Waddington, E.D. Investigator : Bolzan, J.F. 1997-11-30 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/17821 https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/physical/thinsec.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/physical/thinsec.txt English https://www.ncdc.noaa.gov/paleo/study/17821 https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/physical/thinsec.txt R. B. Alley, A. J. Gow, D. A. Meese, J. J. Fitzpatrick, E. D. Waddington, J. F. Bolzan1997Grain-scale processes, folding, and stratigraphic disturbance in the GISP2 ice coreJournal of Geophysical Research: Oceans102C1226819-2683010.1029/96JC03836http://onlinelibrary.wiley.com/enhanced/doi/10.1029/96JC03836/ START YEAR: 110000 cal yr BP * END YEAR: 36000 cal yr BP -38.5 72.6 -38.5 72.6