A Comparison of Deep Antarctic Ice Cores and Their Implications for Climate Between 65,000 and 15,000 Years Ago

Abstract

Three ice cores drilled in the central part of the Antarctic continent extend back to the last glacial period: one from West Antarctica (Byrd) and two from East Antarctica (Vostok and Dome C). This period is also partly covered by a few cores from the coastal areas. In these cores, climatic information is mostly derived from the isotopic profiles (δD or δ¹⁸O) from which surface temperature and, more indirectly, precipitation rate can be estimated. The main objective has been to compare thoroughly the three deep ice cores for the main part of the last glacial period (from ca. 65,000–15,000 yr B.P.). 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 as stratigraphic markers. Elevation changes of the ice sheet, derived from gas content and isotopic data, bear directly on interpretations of past temperature and precipitation rate changes.