Within the framework of the joint European Greenland Ice Core Project (GRIP) a 3029 m long ice core was drilled in Central Greenland from 1989 to 1992 at 72o 35' N, 37o 38' W. Polar ice cores contain a record of tha past atmosphere - temperature, precipitation, gas content, chemical composition, and other properties. The objective of the GRIP effort was to reveal the broad spectrum of information on past environmental, and particularly climatic, changes that are stored in the ice. This information will help investigators understand the major mechanisms of the earth and man's potential impact. Studies of isotopes and various atmospheric constituents in the core have revealed a detailed record of climatic variations reaching more than 100,000 years back in time. The results indicate that Holocene climate has been remarkably stable and have confirmed the occurrence of rapid climatic variation during the last ice age (the Wisconsin). Climatic instability observed in the core part believed to date from the Eemian interglacial has not been confirmed by other climate records. GRIP Drilling Effort In the first drilling season in 1990, the drill reached a depth of 770m where the ice is 3840 years old. In 1991, the drilling continued into 40,000 year old ice at a depth of 2521m, and on 12 August 1992, the drill hit bedrock at 3029m below the surface, where the ice is 200,000 years old or more. The core is now stored in a cold house at the University of Copenhagen. The GRIP deep drill is an updated version of ISTUK (IS means ice in Danish, TUK means drill in Greenlander). ISTUK was constructed in 1978 and used successfully under the American-Danish-Swiss GISP 1 program at Dye 3 in South Greenland where it hit bedrock at a depth of 2037m in 1981. Although the actual drilling was completed in 1992, there was a last short field campaign in Greenland and at Summit to measure ice sheet strain parameters and to extend upward the GRIP hole so that detailed temperature and deformation measurements will still be possible. Using the experience accumulated through GRIP and the facilities of this last campaign, the successful development and testing of a special drill for the European Project for Ice Coring in Antarctica (EPICA) was also carried out. This new European drill will be able to operate in the much harsher environmental conditions to be found at Dome Concordia in Antarctica. Dating the GRIP Core It was possible to count annual layers in the GRIP core to obtain an excellent dating, particularly back to the Younger Dryas period. Parameters used to date the core included ECM, dust, nitrate and ammonium, which all give excellent annual layers, particularly in the Holocene period. Comparison with the previously dated Dye 3 core, using volcanic and other tie-points, provided a starting point. Numerous volcanic eruptions were documented, allowing the possibility to make comparisons with other cores. Deeper ice was dated using ice flow models. Measurements Made on the GRIP Core A huge number of analyses were made on the core in the field, while other samples were prepared in the field for shipment to laboratories around Europe. measurements in the field helped scientists to select samples for special and urgen analyses, and to exclude the contamination risk from chemicals such as organic acids. Continuous measurements made in the field included dielectric profiling and electrical conductivity (related to the concentrations of neutral salts and acid). Thin sections were made in the field to examine crystal sizes and fabrics. Chemical measurements made continuously in the field were ammonium, nitrate, hydrogen peroxide, formaldehyde, calcium and dust, while discontinuous measurements of other anions and cations were made by ion-chromatography. Samples were cut in the field for oxygen isotope and deuterium analysis (with a resolution of about 3 cm in parts of the core), for trace gas analysis, for measurements of 10Be, and mechanical properties of the ice, among others. Findings from the GRIP Core The most dramatic finding from GRIP was that of the rapid climate changes (Dansgaard-Oeschger events) in the last glacial period. These had been observed in previous cores, but GRIP confirmed their existence, their number, and the extreme rapidity of their onset in unprecedented detail. Such work has stimulated paleoclimatologists in other fields to see how global these events are and to look for causes. Among numerous other findings, new insights using markers of biological material have proved particularly exciting. Methane has been found to change in time with many rapid climate changes. Spikes of ammonium and organic acids have been found to be markers for biomass burning, while background concentrations of these species indicate the advances of vegetation in North America. Measurements of borehole temperatures have allowed a re-calibration of the oxygen isotope-temperature relation for the GRIP ice core. This work indicates that the temperature chnage at the end of the last glacial period was more than 20 degrees, a result found independently in the GISP2 borehole. These increased temperature changes provide a renewed challenge to those seeking mechanisms for the transitions. The GRIP core offers a unique possibility to study the growth, rotation and recrystallization of polar ice at an ideal location, covering a time span of more than 100,000 years. This information is obtained by a comprehensive thin section study of crystal sizes and c-axis orientations along its entire length. The results confirm earlier, basic observations on deep ice cores and have led to new insights. A significant variation of crystal size with climatic parameters is shown to persist to a great depth in the core; the development of a strong crystalline anisotropy in the ice sheet is also demonstrated. Considerable insight is obtained into the rheological properties of the ice sheet from these studies. More detailed findings are reported in a large number of papers listed in this CD-ROM, and in the GRIP final report, available also on this CD-ROM. Acknowledgments GRIP has been a multinational European research project, organized through the European Science Foundation (ESF). Funding came from 8 nations (Belgium, Denmark, France, Germany, Iceland, Italy, Switzerland, and the United Kingdom), and from the European Union. GRIP successfully drilled a 3028 meter ice core to the bed of the Greenland ice sheet at Summit. GRIP contributes to the aims of the IGBP PAGES program. The GRIP data are held on the WDC-A Paleoclimatology server. The Program Steering Committee was chaired by: Dr. B. Stauffer Physikalisches Institut der Universitat Bern, Switzerland The GRIP Steering Committee and Management Group Members Include: Dr. B. Stauffer (Steering Committee Chairman) Physikalisches Institut, Bern, Switzerland Dr. H. Miller (Management Group Chairman) Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven, Germany Dr. H. Clausen Institute of Geophysics, University of Copenhagen, Denmark Dr. R. J. Delmas Laboratoire de Glaciologie & Geophysique de l'Environnement, St. Martin d'HSres, France Dr. N. Gundestrup Institute of Geophysics, University of Copenhagen, Denmark Dr. C. Hammer Institute of Geophysics, University of Copenhagen, Denmark Professor S. J. Johnsen Science Institute of Iceland, Reykjavik, Iceland Dr. C. Lorius Laboratoire de Glaciologie & Geophysique de l'Environnement, St. Martin d'HSres, France Dr. H. Oeschger PAGES Core Project Office, Bern, Switzerland Dr. G. Orombelli Dipartimento di Scienze della Terra, Universitia di Milano, Italy Dr. D. Peel British Antarctic Survey, Cambridge, United Kingdom Dr. R. Souchez Dept. des Sciences de la Terre & de l'Environnement, Universite? Libre Brussels, Belgium Dr. E. Wolff British Antarctic Survey, Cambridge, United Kingdom European Science Foundation Dr. M. Fratta Scientific Secretary Mrs. P. Pirra Administrative Secretary Contributing Organizations Belgium: Fonds National de la Recherche Scientifique / Nationaal Fonds voor Wetenschappelijk Onderzoek Denmark: Statens Naturvidenskabelige Forskningsrtd France: Centre National de la Recherche Scientifique (CNRS) Germany: Deutsche Forschungsgemeinschaft (DFG) Iceland: Rannscknarr Islands Italy: Consiglio Nazionale delle Ricerche (CNR) Switzerland: Schweizerischer Nationalfonds zur Forderung der wissenschaftlichen Forschung/Fonds National Suisse de la Recherche Scientifique United Kingdom: Natural Environment Research Council (NERC) Laboratory Address List This list gives the addresses of the main participating laboratories in GRIP. Departement des Sciences de la Terre et de l'Environnement Universite Libre de Bruxelles CP160/03 50 avenue FD Roosevelt 1050 Bruxelles Belgium Department of Geophysics University of Copenhagen Juliane Maries Vej 30 DK 2100 Copenhagen O Denmark Laboratoire de Glaciologie et Geophysique de l'Environnement BP 96 38402 St. Martin d'Heres Cedex France Laboratoire de Modelisation du Climat et de l'Environnement DSM-CEA, l'Orme des Merisiers 91191 Gif-sur-Yvette Cedex France Alfred-Wegener-Institut fur Polar u Meeresforschung Columbusstrasse D-2850 Bremerhaven Germany Science Institute University of Iceland Dunhaga 3 IS-107 Reykjavik Iceland Nordic Volcanological Institute Geoscience Building University of Iceland IS-101 Reykjavik Iceland Dipart di Scienze della Terra Via Mangiagalli 34 I-20133 Milano Italy Physikalisches Institut Universitat Bern Sidlerstrasse 5 CH-3012 Bern Switzerland British Antarctic Survey High Cross Madingley Road Cambridge CB3 0ET United Kingdom Greenland Ice Core Project Final Report The "Greenland Ice Core Project, An ESF Research Programme: Final Report" summarizes the results obtained by the GRIP Project. To download the report either as a Word 6.0 file (gripfinl.doc) or as an ascii file (gripfinl.txt) see the online folder: http://www.ncdc.noaa.gov/paleo/icecore/greenland/summit/document/finalrpt/