Gao Yongpeng, Wang Jinliang, Liu Shiyin, Yao Xiaojun, Qi Miaomiao, Liang Pengbin, Xie Fuming, Mu Jianxin, Ma Xinggang
Faculty of Geography, Yunnan Normal University, Kunming 650500, China; Key Laboratory of Resources and Environmental Remote Sensing for Universities in Yunnan, Kunming 650500, China; Center for Geospatial Information Engineering and Technology of Yunnan Province, Kunming 650500, China; Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province, Northwest Normal University, Lanzhou 730070, China.
Faculty of Geography, Yunnan Normal University, Kunming 650500, China; Key Laboratory of Resources and Environmental Remote Sensing for Universities in Yunnan, Kunming 650500, China; Center for Geospatial Information Engineering and Technology of Yunnan Province, Kunming 650500, China.
Sci Total Environ. 2024 Jun 10;928:172467. doi: 10.1016/j.scitotenv.2024.172467. Epub 2024 Apr 13.
Glacier surges, a primary factor contributing to various glacial hazards, has long captivated the attention of the global glaciological community. This study delves into the dynamics of Kyagar Glacier surging and the associated drainage features of its Ice-dammed lake, employing high temporal resolution optical imagery. Our findings indicate that the surge on Kyagar Glacier began in late spring and early summer of 2014 and concluded during the summer of 2016. This surge resulted in the transfer of 0.321 ± 0.012 km of glacier mass from the reservoir zone to the receiving zone, leading to the formation of an ice-dammed lake at the glacier's terminus. The lake experienced five outbursts between 2015 and 2019, with the largest discharge occurring in 2017. And the maximum water depth during this period was 112 ± 11 m, resulting in a water storage volume of (158.37 ± 28.32) × 10 m. On the other hand, our analysis of the relationship between glacier surface velocity and albedo, coupled with an examination of subglacial dynamics, revealed that increased precipitation during the active phase of the Kyagar Glacier results in accumulation of mass in the upper glacier. This accumulation induces changes in basal shear stress, triggering the glacier's transition into an unstable state. Consequently, glacier deformation rates escalate, surface crevasses proliferate, potentially providing conduits for surface meltwater to infiltrate the glacier bed. This, in turn, leaded to elevated basal water pressure, initiating glacier sliding. Furthermore, we postulated that the repetitive drainage of Kyagar Ice-dammed lake was primarily influenced by the opening and closing of subglacial drainage pathways and variations in inflow volumes. Future endeavors necessitate rigorous field observations to enhance glacier surge simulations, deepening our comprehension of glacier surge mechanisms and mitigating the impact of associated glacial hazards.
冰川跃动是导致各种冰川灾害的一个主要因素，长期以来一直吸引着全球冰川学界的关注。本研究利用高时间分辨率光学影像，深入探究了卡亚加尔冰川跃动的动力学及其冰碛湖的相关排水特征。我们的研究结果表明，卡亚加尔冰川的跃动始于2014年春末夏初，并于2016年夏季结束。这次跃动导致0.321±0.012千米的冰川物质从储水区转移到接收区，在冰川末端形成了一个冰碛湖。该湖在2015年至2019年间经历了五次决堤，最大流量发生在2017年。在此期间，最大水深为112±11米，蓄水量为(158.37±28.32)×10立方米。另一方面，我们对冰川表面速度与反照率之间关系的分析，以及对冰下动力学的研究表明，卡亚加尔冰川活跃期降水增加导致冰川上部物质积累。这种积累引起基底剪应力变化，促使冰川转变为不稳定状态。因此，冰川变形速率加快，表面裂缝增多，可能为地表融水渗入冰川底部提供通道。这反过来又导致基底水压升高，引发冰川滑动。此外，我们推测，卡亚加尔冰碛湖的反复排水主要受冰下排水通道的开合和入流量变化的影响。未来的工作需要进行严格的实地观测，以加强冰川跃动模拟，加深我们对冰川跃动机理的理解，并减轻相关冰川灾害的影响。
