乌鲁木齐河源1号冰川不同时期雪层剖面及成冰带对比研究

对20世纪60年代、80年代和21世纪初天山乌鲁木齐河源1号冰川(以下简称1号冰川)雪层剖面特征、成冰带的对比分析研究,发现自20世纪60年代以来,1号冰川雪层剖面厚度明显减薄,结构变得简单,各层界限变得模糊.成冰带类型及其分布发生了明显变化,60年代存在于冷气候条件下的冷渗浸带,80年代被渗浸带所替代.21世纪初,1号冰川成冰带变化更为显著,尤其是东支,顶部已具有消融带特征.研究表明,20世纪80年代以来河源区气候变暖是导致上述变化的主要原因.

A Contrast of the Ice Formation Time,Ice Formation Zones and the Stratigraphic Profiles of Snow Pits in Different Time of the Glacier No.1 at the Headwaters of the Ürüqi River,Tianshan Mountains

With the contrastive analyses of the ice formation time,ice formation zones and the stratigraphic snow profiles,the constitution of the profiles,the distribution and the shift of dust layers and the ice layers within snow layers of the Glacier No.1 at the headwaters of the Ürümqi River,Tianshan Mountains,in different time(the 1960s and the 1980s and the beginning of this century),it is found that: since the 1960s,the snow depth on the glacier has decreased,the number and the buried depth of the dust layers and ice layers have decreased,and the profile constitution has changed with the increase of mean density.Ice formation zones have changed also.All the upper limitations of the zones are rising,and the cold percolation zone disappeared and was replaced by percolation zone.The most interesting thing is that the top of the east branch was replaced by an ablation area.With a new method--tracking the marks buried in snow profiles,the ice formation time was determined to be 3.5～4 years.The change of heat state in the snow profiles caused by climate change,especially the temperature rising,is the main reason for the changes.Temperature rising results in more snow melted,and causes the decrease of snow depth,decrease or disappearance of dust layers and ice layers.