Distribution of stable isotopes in surface snow along the route of the 1990 International Trans-Antarctica Expedition

Abstract

Presents the distribution of average δD and δ18O values for the top 1 m of surface snow for a large area of Antarctica. The empirical relationships between the isotopes, temperature and elevation are computed. The slopes of δD with respect to the surface temperature for the segments west (Patriot Hills-Vostok) and east of Vostok (Komsomolskaya-Mirny) are not significantly different to that observed between Dumot d'Urville and Dome C (Lorius and Merlivat, 1977) which are often used to interpret deep ice-core isotopic profiles. There is, however, a noticeable shift between the two regression lines with, for a given temperature, higher isotopic values west of Vostok. The deuterium excess values (d = δD-8 × δ18O) increase sharply at 3000 m a.s.l. on the plateau, confirming the results of Petit and others. -from Authors