noaa-icecore-17857 GRIP Ice Core Texture and Fabric Data Thorsteinsson, T.; Kipfstuhl, J.; Miller, H. GRIP Ice Core Texture and Fabric Data 1997-11-30 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/17857 Investigator T. Thorsteinsson Investigator J. Kipfstuhl Investigator H. Miller earth science paleoclimate ice cores inclination,bulk ice,null,degree,null,ice cores,null,null,N,ice crystal inclination earth science paleoclimate ice cores grain size mean,bulk ice,null,millimeter,null,ice cores,null,null,N,average vertical crystal diameter earth science paleoclimate ice cores azimuth,bulk ice,null,degree,null,ice cores,null,null,N,ice crystal azimuth 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 grain size mean,bulk ice,null,millimeter,null,ice cores,null,null,N,average horizontal crystal diameter earth science paleoclimate ice cores depth,null,null,meter,null,ice cores,null,null,N,null earth science paleoclimate ice core physical properties geoscientificInformation 248000 cal yr BP 375 cal yr BP Complete 72.58 72.58 -37.63 -37.63 Continent North America Greenland GRIP>LATITUDE 72.58>LONGITUDE -37.63 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 Thorsteinn Thorsteinsson, Josef Kipfstuhl, Heinz Miller 1997 Journal of Geophysical Research: Oceans 102 C12 26583-26599 10.1029/97JC00161 http://onlinelibrary.wiley.com/enhanced/doi/10.1029/97JC00161/

A comprehensive study of textures and fabrics has been carried out on the Greenland Ice Core Project (GRIP) ice core. Crystal sizes and c axis orientations have been measured on thin sections with conventional techniques, yielding new information on the growth, rotation and recrystallization of ice crystals in the Greenland Ice Sheet. Normal grain growth is found to persist to a depth of 700 m in the core, where the onset of polygonization due to increasing strain prevents a further increase in grain size in the Holocene ice. Smaller crystals are observed in the Wisconsin ice, larger crystals are found in the Eemian ice, and the crystal size is found to vary with climatic parameters in these periods. This dependence, which probably results from variable impurity content in the ice, persists to a depth of 2930 m. Coarse-grained ice, probably resulting from rapid growth of crystals at comparatively high temperatures, is found in the lowest 100 m of the core. The data on c axis orientations reveal a steady evolution of the fabric from random near the surface to a strong single maximum in the lower part of the ice sheet. A significant strengthening is not observed at the Holocene-Wisconsin transition. The fabric development indicates that vertical compression at the ice divide is the main mode of deformation down to a depth of 2850 m. The evolution toward a single maximum fabric hardens the ice against vertical compression but softens it against simple shear. Evidence of simple shear deformation is clearly observed between 2850 m and 2950 m depth. Stretched fabrics in coarse-grained ice in the lowest 100 m could be due to tensional stresses; this ice is unlikely to be undergoing any significant horizontal deformation at the present time. STUDY NOTES: Average horizontal and vertical crystal diameters are given, obtained by linear-intercept measurements on thin sections. The data making up the 36 fabric diagrams published in the article (Thorstiensson, 1997) are included in a separate file.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/physical/fabric.txt Data File; GRIP Ice Fabric GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/physical/caxis.txt Data File; GRIP c-axis orientations USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11