天山托木尔峰地区青冰滩72号冰川表面运动速度特征研究

Features of the Surface Flow Velocity on the Qingbingtan Glacier No.72,Tianshan Mountains

托木尔峰地区是天山最大的冰川分布区,是阿克苏地区主要水资源补给地.一直以来,该区冰川运动资料空白,严重阻碍了对冰川水资源现状及未来变化评估工作的开展.鉴于以上情况,中国科学院天山冰川站在2008年8月到2009年8月3次开展了对天山托木尔峰青冰滩72号冰川表面运动速度的观测,获得了冰川表面运动速度特征变化状况.结果表明:青冰滩72号冰川冰舌区域运动速度存在明显的消融季和非消融季的差异,消融季速度偏大.年均水平运动速度47.1m.a-1速度分布受局地地形因素影响明显.与天山乌鲁木齐河源1号冰川相比,该冰川运动速度明显偏大,消融季底部滑动显著,其运动特征更偏向海洋性冰川.

Movement is the main characteristic making glacier ice differ from other ice in nature.Observation of surface flow velocity is a basic method to study the glacier movement.Tomur Peak is the region with the highest concentration of glaciers in the Tianshan Mountains,and the glaciers are the main water resources for Aksu Municipality.Because of the important role of glaciers in local water resources,to study the current state and future evolution of the glaciers and glacial runoff in the municipality is urgent need.However,the study is hampered,because there is almost no observed glacier movement data here.To fill the blank,in August 2008,a large-scale scientific expedition was taken by Tianshan Glaciological Station,during which 21 stakes were set on the glacier for glacier flow velocity and mass balance observations.The Global Positioning System was applied to monitor the stake position.In July and August 2009,the measurement of the position of stakes was taken repeatedly.According to all the measured data,the features of surface flow velocity of the glacier is obtained,showing that the maximum horizontal surface velocity was around 73.4 m·a-1,averaging at 47.1 m·a-1 in the tongue area.The spatial distribution of velocity was highly correlated with geometry of the glacier surface.There is obvious seasonality of the surface flow velocity.In detail,the velocities in the ablation season are significantly higher than that in non-melting season.In addition to the contribution of basal sliding,the ablation season velocity is also impacted by the ablation at the glacier bottom.Comparing to the corresponding features of the ürümqi Glacier No.1,the velocity of Qingbingtan Glacier No.72 is much higher,the mass transport by movement is more active,and the basal sliding is more significant.Generally,the velocity features of the Qingbingtan Glacier No.72 are similar to those of maritime glaciers in China.