1970—2007年西藏念青唐古拉峰南、北坡冰川显著退缩

Glacier Retreating Dramatically on the Mt.Nyainqêntanglha During the Last 40 Years

1999年和2007年夏季,利用GPS技术先后对念青唐古拉峰(念峰)南、北坡的5条冰川末端位置进行了实地测量.结果表明:同1970年比较发现,过去近40 a来5条冰川退缩显著,1970-2007年间念峰北坡的拉弄和扎当冰川与南坡的爬努冰川末端平均退缩速率均接近10.0 m.a-1;西布冰川在1970-1999年间达到38.9 m.a-1,而爬努冰川流域海拔较高的小冰川5O270C0049退缩幅度较小,为4.8 m.a-1.2007年野外观测发现,爬努冰川1970年代的积累区有冰面河形成.念峰周围的冰川变化,不仅仅是末端的显著退缩,而且消融区面积也在扩大.

During the expeditions to Mt. Nyainqentanglha in the summer of 1999 and 2007, glacier termini had been surveyed using GPS tech- nology for five glaciers around the mount. Comparing the terminus positions surveyed by the two GPS with those surveyed in 1970 reveal that five glaciers have retreated since 1970. The retreat rate of glacier termini is around 10. 0 m · a^-1 for the Lanong and Zhadang Glaciers in the northern slopes of the mount and the Panu Glacier in thesouthern slope during 1970--2007. However, retreat of the Xibu Glacier is dramatic with a rate of 38.9 m · a^-1, while a small high-elevation glacier （50270C0049） in the Panu basin has a low retreat rate of 4.8 m ·a^-1. A stream was observed in the 1970＇s firn basin of the Panu Glacier, indicating that not only the glacier termini are retreating dramatically but also the ablation areas are expanding around the mount.