{"NOAAStudyId":"17877","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-17877.xml","doi":null,"earliestYearBP":167726,"earliestYearCE":-165776,"entryId":"noaa-icecore-17877","funding":[],"investigators":"Chappellaz, J.A.; Brook, E.J.; Blunier, T.; Malaize´, B.","mostRecentYearBP":111556,"mostRecentYearCE":-109606,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/17877","originalSource":null,"publication":[{"abstract":"The suggestion of climatic instability during the last interglacial period (Eem), based on the bottom 10% of the Greenland Ice core Project (GRIP) isotopic profile, has been questioned because the bottom record from the neighboring Greenland Ice Sheet Project 2 (GISP2) core (28 km away) is strikingly different over the same interval and because records of the d18O of atmospheric O2 from both cores showed unexpected rapid fluctuations. Here we present detailed methane records from the Vostok (Antarctica), GRIP, and GISP2 cores over the relevant intervals. The GRIP and GISP2 data show rapid and large changes in methane concentration, which are correlative with variations of the d18O of the ice, while the Vostok record shows no such variations. This discrepancy reinforces the suggestion that the bottom sections of the Greenland records are disturbed. By combining the methane data with measurements of d18O of O2 in the same samples, we attempt to constrain the nature of the stratigraphic disturbance and the age of the analyzed ice samples. Our results suggest that ice layers from part of the last interglacial period exist in the lower section of both ice cores and that some of the apparent climate instabilities in the GRIP core would be the result of a mixture of ice from the last interglacial with ice from the beginning of the last glaciation or from the penultimate glaciation.","author":{"name":"Jerome Chappellaz, Ed Brook, Thomas Blunier, Bruno Malaize"},"citation":"Jerome Chappellaz, Ed Brook, Thomas Blunier, Bruno Malaize. 1997. CH4 and d18O of O2 records from Antarctic and Greenland ice: A clue for stratigraphic disturbance in the bottom part of the Greenland Ice Core Project and the Greenland Ice Sheet Project 2 ice cores. Journal of Geophysical Research: Oceans, 102(C12), 26547-26557. doi: 10.1029/97JC00164","edition":null,"identifier":{"id":"10.1029/97JC00164","type":"doi","url":"http://dx.doi.org/10.1029/97JC00164"},"issue":"C12","journal":"Journal of Geophysical Research: Oceans","pages":"26547-26557","pubRank":"1","pubYear":1997,"reportNumber":null,"title":"CH4 and d18O of O2 records from Antarctic and Greenland ice: A clue for stratigraphic disturbance in the bottom part of the Greenland Ice Core Project and the Greenland Ice Sheet Project 2 ice cores","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":"28179","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>ice core>oxygen isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/gases/oxygas.txt","linkText":"GRIP Oxygen-18 of Atmospheric Oxygen","urlDescription":"Data File","variables":[{"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":"chemical composition>element or single-element molecule>oxygen gas","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil","cvWhat":"chemical composition>isotope>isotope ratio>delta 18O"}]}],"dataTableName":"GRIP1997d18Oatm","dataTableNotes":null,"earliestYear":167726,"earliestYearBP":167726,"earliestYearCE":-165776,"mostRecentYear":111556,"mostRecentYearBP":111556,"mostRecentYearCE":-109606,"species":[],"timeUnit":"cal yr BP"}],"siteName":"GRIP"}],"studyCode":null,"studyName":"GRIP Ice Core d18O of Atmospheric Oxygen","studyNotes":"d18O values (permil against modern air taken in Normandie, France, in 1995). \nd18O measured on oxygen in the bubble air from ice cores is a proxy for continental ice volume and is used to synchronize cores from Greenland and Antarctica ","version":"1.0","xmlId":"15590"}