西藏阿里地区大、小昂龙冰川变化观测研究

Variation of the Large and Small Anglong Glaciers in the Ngari Prefecture,Tibet,China

在西藏阿里地区狮泉河上游的大、小昂龙冰川开展了连续2年(2014—2016年)的冰川变化地面观测,主要包括冰川表面物质平衡与差分GPS高程变化同步观测,以及冰川表面流速观测,冰川末端观测和冰川雷达测厚。观测结果表明:大、小昂龙冰川表面物质平衡与同期差分GPS观测结果之间存在差异。冰川表面物质平衡结果显示,2014—2016年间,大、小昂龙冰川分别以每年72mm w.e.和219mm w.e.的速率减薄。差分GPS观测结果显示,同期大、小昂龙冰川分别以每年(442±90)mm w.e.和(265±90)mm w.e.的速率减薄;在2015/2016年,大、小昂龙冰川表面平均流速分别为4.4m·a^(-1)和2.3m·a^(-1),其中大昂龙冰川表面平均流速较上一物质平衡年增加了10.5%;2014—2016年间,小昂龙冰川先是前进了11m,之后又退缩了34m,两年内平均每年退缩11.5m;大昂龙冰川平均冰厚为67.9m,实测最大厚度为216m,根据雷达测厚数据插值计算的冰川储量为0.452km3;小昂龙冰川实测最大厚度为190m。

A two consecutive years(2014—2016)of research had been conducted on the Large and Small Anglong Glaciers,located in the upper Shiquanhe River,Ngari Prefecture,Tibet Autonomous Region,including simultaneous observation of glacier surface mass balance by stake method and difference GPS,as well as glacier surface flow velocity,change of glacier terminal and ice thickness.The followings were revealed:1)The results of difference GPS method and the surface mass balance by stake method had differ somewhat for the two glaciers during 2014—2106.The stake method showed that the Large and Small Anglong Glaciers reduced by 72 mm w.e.·a^(-1)and 219 mm w.e.·a^(-1),respectively,during 2014—2016.However,the difference GPS method showed that the two glaciers reduced by(442±90)mm w.e.·a^(-1)and(265±90)mm w.e.·a^(-1),respectively,at the same time period.2)The surface flow velocities for the two glaciers were 4.4 m·a^(-1)and 2.3 m·a^(-1)in 2015/2016,respectively.3)During 2014—2016 the Small Anglong Glacier had advanced 11 meters in the first year and then retreated 34 meters in the second year;4)The volume of the Large Anglong Glacier was 0.452 km3 with an average ice thickness of 67.9 meters and a maximum measured thickness of 216 meters.The maximum thickness of the Small Anglong Glacier was 190 meters.