1960-2009年中国天山现代冰川末端变化特征

Variation of Glacier Terminuses in the Tianshan Mountains, China,during the Period of 1960-2009

基于冰川定位观测、野外考察、航空摄影、遥感影像和地形图分析方法,研究了1960—2009年中国天山8条冰川末端变化特征。结果表明:1960—2009年,在天山地区气温与降水呈上升趋势的背景下,8条冰川均处于退缩状态,退缩速率由西向东逐渐减缓,其变化幅度因气候环境、地理位置、冰川规模和冰川形态等的不同而存在明显的区域性与阶段性差异。其中,乌鲁木齐河源1号冰川1962—1973年冰川末端退缩速率为5.96m.a-1,1973—1980年为3.28m.a-1,1980—1993年为3.93m.a-1,在1993年完全分离成东、西两支独立的冰川;博格达峰四工河4号冰川末端1962—1981年退缩速率为6m.a-1,1981—2006年为8.9m.a-1,2006—2009年为13.3m.a-1。表碛覆盖的青冰滩72号冰川和74号冰川末端1964—2009年退缩速率分别为41m.a-1和30m.a-1,远较无表碛覆盖的庙儿沟平顶冰川退缩迅速(1972—2007年冰川末端退缩速率为2.32m.a-1)。表面特征(表碛)亦是造成冰川变化差异的一个主要原因。

The terminus variation of eight glaciers in the Tianshan Mountains, China, during the period of 1960 - 2009 was studied based on the located observation, field survey, aerial photography, remote sensing and topography analysis. Results showed that the eight glaciers kept retreat during the period of 1960 -2009 under the background of the increase of both temperature and precipitation in the Tianshan Mountains, China, and the retreat rate reduced gradually from west to east. There were the regional and periodical changes of the glacier terminuses owing to climate change and the differences of geographical locations and glacier scales and types. Thereinto, the retreating rate of Glacier No. 1 at headwaters of the Urumqi River was 5.96 m ~ a-1 during the period of 1962 - 1973, it was decreased to 3.28 m .a^-1 during the period of 1973 - 1980, increased slightly （3.93 m . a^-1 ） during the period of 1980 - 1993, and the glacier was divided into two independent ones in 1993. The retreating rate of Glacier No. 4 in the Sigong River Basin in the Bogda Peak region was 6 m. a^-1 during the period from 1962 to 1981, increased to 8.9 m . a^-1 during the period of 1981 -2006 and to 13.3 m.a^-1 during the period of 2006 -2009. Furthermore, Qingbingtan Glacier No. 72 and No. 74 covered by superglacial moraine retreated with rates of 41 -1 -1 -1 m . a and 30 m . a during the period of 1964 -2009, these rates were much higher than that （2.32 m . a ） of the Miaoergou Flat-topped Glacier without superglacial moraine during the period of 1972 - 2007. The surface morphology （superglacial moraine） is another cause resulting in the difference of glacier change in the Tianshan Mountains.