Along a 5986 km route on Antarctic ice sheet from west to east, 106 snow pits with a depth ranging from 1.0—2.0 m have been dug by the first author of this paper, the Chinese member of the '1990 International Tra...Along a 5986 km route on Antarctic ice sheet from west to east, 106 snow pits with a depth ranging from 1.0—2.0 m have been dug by the first author of this paper, the Chinese member of the '1990 International Trans-Antarctic Expedition'. The basic physical characteristics of the surface layer of the ice sheet on a large scale are obtained through the observations of snow profiles at these snow pits. The sastrugi shapes and major axis azimuths have also been observed or measured on the way. Analysis for these observation data shows that in West Antarctica the meltwater infiltration-congelation is obvious and the annual precipitation is larger than that in East Antarctica, which implies that climate in West Antarctica is warmer, more humid and influenced more greatly by the South Ocean than that in East Antarctica. Radiation ice-glazes frequently found in snow profiles indicate that even in East Antarctica under very low temperatures, surface 'melting' occurs in summer due to the long-time solar radiation. The little variations of sastrugi trend and its dominant azimuth in the inland Antarctica suggest that there is a south-north prevailing wind. Depth hoar is very much developed in the snow pits of East Antarctica. This possesses important climatic and glaciological significance but its formation mechanism and development process need a further discussion elsewhere.展开更多
基金Project supported by the National Natural Science Foundation of China and the State Committee for Antarctic Research of China.
文摘Along a 5986 km route on Antarctic ice sheet from west to east, 106 snow pits with a depth ranging from 1.0—2.0 m have been dug by the first author of this paper, the Chinese member of the '1990 International Trans-Antarctic Expedition'. The basic physical characteristics of the surface layer of the ice sheet on a large scale are obtained through the observations of snow profiles at these snow pits. The sastrugi shapes and major axis azimuths have also been observed or measured on the way. Analysis for these observation data shows that in West Antarctica the meltwater infiltration-congelation is obvious and the annual precipitation is larger than that in East Antarctica, which implies that climate in West Antarctica is warmer, more humid and influenced more greatly by the South Ocean than that in East Antarctica. Radiation ice-glazes frequently found in snow profiles indicate that even in East Antarctica under very low temperatures, surface 'melting' occurs in summer due to the long-time solar radiation. The little variations of sastrugi trend and its dominant azimuth in the inland Antarctica suggest that there is a south-north prevailing wind. Depth hoar is very much developed in the snow pits of East Antarctica. This possesses important climatic and glaciological significance but its formation mechanism and development process need a further discussion elsewhere.
