天山南坡科其喀尔冰川消融区运动特征分析

Analysis of the flow features in the ablation zone of the Koxkar Glacier on south slopes of the Tianshan Mountains

基于2009年5月至2011年10月科其喀尔冰川的花杆观测资料，对其消融区的表面运动特征进行分析．结果表明：冰川消融区的年水平运动速度最大值为86．69m·a^-1，年垂直运动速度最大值为15．34m·a^-1，均出现在冰川海拔4000—4200m的消融区上部；在靠近冰川末端的冰舌下部，受冰量补给减弱、厚层表碛覆盖等影响，冰川运动缓慢，年水平运动速度小于5m·a^-1，而垂直运动速度值小于2m·a^-1．大多数横剖面的水平运动速度具有从中部向边缘逐渐减小的特征，而有的剖面却出现局部速度增大的区域．整体而言，冰川水平及垂直运动速度随海拔降低而减小，符合冰川运动的一般规律，但丰要受地形作用的影响，垂直运动速度随海拔的变化会出现波动．消融期月水平运动速度与同期气温和降水的变化具有一定的相关性，可能反映出气候快速变化对冰川运动的影响．

Based on high-resolution GPS measurements on the Koxkar Glacier in the Tianshan Mountains, the spatial-temporal variations of flow velocity on the glacier were analyzed. The fastest flow was found near the e- quilibrium line （4 000 -4 200 m a. s. 1. ）, of which the horizontal flow velocity reached 86.69 m · a^- 1 and the vertical flow velocity reached 15.34 m · a^-1. In the lower part of the glacier, where the extensive debris cover developed, ice flow was slower, with horizontal ice velocity varying between 0 - 5 m · a^- 1, and vertical ice velocity varying between 0 - 2m · a^- 1, due to reduction in supply of ice mass and influence of thick debris cover. The variation of flow velocity with elevation met the general glacier flow law, but due to the influence of terrain, occasionally there was some spatial fluctuation in vertical flow velocity. Analysis of the seasonal variation of flow velocity reveals a good relationship between ice flow and climate factors, which may reflect the response of glac- ier flow to fast climate change.