南极洲纳尔逊冰帽雪层剖面和冰川化学特征

Nelson冰帽位于南极洲边缘地区,周围海洋环绕。雪层剖面受融水干扰,但综合分析后仍能观察到季节变化的轮廓。结合雪层剖面和杂质成分及浓度分析,推知这里以局地海洋气团降水为主,冬季降水中杂质含量高于夏季,平均杂质含量远远高于内陆,人类活动等对环境的影响已在雪层中留下痕迹。但NO_3~-的沉积速率在整个西南极洲相差不显著,大气圈作用是控制NO_3~-沉积的主要因素。

CHARACTERISTICS OF STRATIGRAPHY AND GLAGIOGHEMISTRY ON TOP OF NELSON ICE CAP, ANTARCTICA

The Nelson Ice Cap, surrounding by ocean, located in the low latitute region of Antarctica. The stratigiaphy and ions in a snow pit on the top of the Nelson Ice Cap were studied. The results reflect that there are complex stratigraphic events in the snow pit, but the marks of seasonal variation of the snow still have been conserved. According to the analysis of ionic concentrations of snow samples collected from the snow pit and this seasonal varies, the impurity concentrations of precipitations in Nelson Is. region "are higher than those in inland. The precipitation origin is from local marine air mass. The high concentration of ions also points out that the environment of Nelson Is. region have been affected by the human activities. The deposition rates of nitrate are similar in West Antarctica, which suggests that the atmospheric process plays an important role to control the deposition rate of nitrate.