DISTRIBUTION OF DELTA-D IN 25-CM SURFACE SNOW ALONG TRANS-ANTARCTIC ROUTE .2. THE 1990 INTERNATIONAL TRANS-ANTARCTIC EXPEDITION GLACIOLOGICAL RESEARCH

On the way of the ''1990 International Trans-Antarctic Expedition'', t he first author of this paper, the Chinese member of the expedition, c ollected 104 snow samples in 25-cm surface snow along a 5986-km route on Antarctic ice sheet from west to east. The geographical distributio n of deltaD across the Antarctica by the longest route is obtained fro m stable isotope analysis for the first time. After discussing regiona l differences of physical geographic conditions, maritime-continental influence, altitudes and latitudes at sampling sites, the distribution of deltaD is considered to have a close relation to latitudes, but th e topographic effect is prominent in some particular regions. The mean annual temperature at sampling site and its relationship with deltaD in surface snow covering Antarctica from west to east are discussed al so. The deltaD-temperature gradient from the south end of Antarctic Pe ninsula to Vostok obtained in this paper is very close to that in Terr e Adelie Land obtained by predecessors. The snow-drift may make an imp ortant. contribution to the relatively high deltaD-temperature gradien t from Vostok to Mirnyy.