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PORTAIL D'INFORMATION GÉOGRAPHIQUE

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  • A comparison of deep Antarctic ice cores and their implications for climate between 65,000 and 15,000 years ago
  • In these cores, climatic information is mostly derived from the isotopic profiles (deuterium/hydrogen and/or 18O/16O ratios) from which surface temperature and, more indirectly, precipitation rate can be estimated. The time scales have been examined
  • in detail and a new 40,000 yr chronology for the Dome C core adopted. Special emphasis is placed on the link between the concentration of 10Be and past accumulation changes and on the use of peaks in the concentration of this cosmogenic isotope
  • AMS-14C ages measured in deep sea cores from the Southern Ocean : implications for sedimentation rates during isotope stage 2
  • C14 dates obtained by accelerator mass spectrometry (AMS) on monospecific foraminiferal samples from two deep-sea sediment cores raised in the Indian sector of the southern Ocean have been corrected for the difference in C14 composition between
  • atmosphere and sea surface by using a reconstruction of the latitudinal C14 gradient which existed in the Southern Ocean prior to 1962. The corrected AMS-C14 data show a reduced sedimentation rates in core MD 84-527 between 25,000 and 10,000 yr B.P. For core
  • Pingos in Antarctica appear to be residual landforms that have formed on the surface of the moraine as the ice core has been destroyed by ablation and thermal erosion. This interpretation appears to have misinterpreted tension cracks and coherent
  • of the ice core of moraines.
  • Evidence from terrestrial sections, ice cores, and marine cores are reviewed and used to develop a scenario for environmental change in the area of the extreme northwest North Atlantic during marine isotope stages 5 and 4.
  • Surface mass-balance variability near Byrd Station, Antarctica, and its importance to ice core stratigraphy
  • Dating of Greenland ice cores by flow models, isotopes, volcanic debris, and continental dust
  • Retreat of ice scarps on an ice-cored moraine, Vestfold Hills, Antarctica
  • Glaciological interpretation of microparticle concentrations from the French 905 m Dome C, Antarctica core in Sea level ice and climatic change.
  • Evidence of climatic change in Antarctica over the last 30 000 years from the Dome C ice core in Sea level ice and climatic change.
  • The AA. describe here late Quaternary paleoclimate, ice-volume change, and dynamics of the Ross ice drainage system using data from a powerful combination of drift sheets and ice cores.
  • Pollen analysis of the 1973 ice core from Devon Island glacier, Canada
  • and arctic air were more widespread and pollen sources were more distant| thus, at this time relatively little pollen was incorporated into the ice. The Devon ice-core data suggest that there should have been pollen in the continental ice sheet of Wisconsin
  • before 2 200 yr B.P. The Holocene temperature changes of between 0.5 and 1.0o C are comparable in scale and timing to those identified from recent analyses of Vostok ice cores from the Antarctic ice sheet.
  • L'origine des fjords de l'Arctique occidental est à associer non seulement à des facteurs d'érosion ou d'exaration glaciaire, mais à des processus globaux de formation de failles et d'un enfoncement non compensé le long de la périphérie nord-ouest
  • La nécessité d'établir une telle carte se faisait sentir depuis longtemps. Selon le principe d'une division purement morphologique, sans aucune interprétation génétique, les AA. distinguent, sur leur schéma de la périphérie continentale nord de
  • Piston cores and single-channel seismic reflection data were collected during the Deep Freeze 85 and 86 expeditions to determine the late Quaternary history of the area. Seismic data in the bay show a rugged seafloor, with numerous deep troughs
  • The history of the Holocene transgression is reconstructed in the area of the present straits between Siberia and Alaska using modern assemblages of benthonic foraminifera from 26 cores. The relative sequence of events progresses from a wind swept