{"NOAAStudyId":"17857","contactInfo":{"address":"325 Broadway, E/NE31","city":"Boulder","constraints":"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.","country":"USA","dataCenterUrl":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data","email":"paleo@noaa.gov","fax":"303-497-6513","longName":"National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce ","phone":"303-497-6280","postalCode":"80305-3328","shortName":"DOC/NOAA/NESDIS/NCEI","state":"CO","type":"CONTACT INFORMATION"},"contributionDate":"1997-11-30","dataPublisher":"NOAA","dataType":"ICE CORES","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/ice-core","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-icecore-17857.xml","doi":null,"earliestYearBP":248000,"earliestYearCE":-246050,"entryId":"noaa-icecore-17857","funding":[],"investigators":"Thorsteinsson, T.; Kipfstuhl, J.; Miller, H.","mostRecentYearBP":375,"mostRecentYearCE":1575,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/17857","originalSource":null,"publication":[{"abstract":"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.","author":{"name":"Thorsteinn Thorsteinsson, Josef Kipfstuhl, Heinz Miller"},"citation":"Thorsteinn Thorsteinsson, Josef Kipfstuhl, Heinz Miller. 1997. Textures and fabrics in the GRIP ice core. Journal of Geophysical Research: Oceans, 102(C12), 26583-26599. doi: 10.1029/97JC00161","edition":null,"identifier":{"id":"10.1029/97JC00161","type":"doi","url":"http://dx.doi.org/10.1029/97JC00161"},"issue":"C12","journal":"Journal of Geophysical Research: Oceans","pages":"26583-26599","pubRank":"1","pubYear":1997,"reportNumber":null,"title":"Textures and fabrics in the GRIP ice core","type":"publication","volume":"102"}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"19973","geo":{"geoType":"Feature","geometry":{"coordinates":["72.58","-37.63"],"type":"POINT"},"properties":{"easternmostLongitude":"-37.63","maxElevationMeters":null,"minElevationMeters":null,"northernmostLatitude":"72.58","southernmostLatitude":"72.58","westernmostLongitude":"-37.63"}},"locationName":"Continent>North America>Greenland","mappable":"Y","paleoData":[{"NOAADataTableId":"28176","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>ice core>physical properties"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/physical/caxis.txt","linkText":"GRIP c-axis orientations","urlDescription":"Data File","variables":[{"cvAdditionalInfo":"average vertical crystal diameter","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"hydrologic material>bulk ice","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"millimeter","cvWhat":"physical property>diameter>grain size>grain size parameter>grain size mean"},{"cvAdditionalInfo":"average horizontal crystal diameter","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"hydrologic material>bulk ice","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"millimeter","cvWhat":"physical property>diameter>grain size>grain size parameter>grain size mean"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"meter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age>ice age"}]},{"NOAAKeywords":["earth science>paleoclimate>ice core>physical properties"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/physical/fabric.txt","linkText":"GRIP Ice Fabric","urlDescription":"Data File","variables":[{"cvAdditionalInfo":"ice crystal azimuth","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"hydrologic material>bulk ice","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"degree","cvWhat":"physical property>angle>azimuth"},{"cvAdditionalInfo":"ice crystal inclination","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"hydrologic material>bulk ice","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"degree","cvWhat":"physical property>angle>inclination"}]}],"dataTableName":"GRIP1997fabric","dataTableNotes":null,"earliestYear":248000,"earliestYearBP":248000,"earliestYearCE":-246050,"mostRecentYear":375,"mostRecentYearBP":375,"mostRecentYearCE":1575,"species":[],"timeUnit":"cal yr BP"}],"siteName":"GRIP"}],"studyCode":null,"studyName":"GRIP Ice Core Texture and Fabric Data","studyNotes":"Average horizontal and vertical crystal diameters are given, obtained by\nlinear-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.","version":"1.0","xmlId":"15582"}