A Glacier Surge of Bivachny Glacier, Pamir Mountains, Observed by a Time Series of High-Resolution Digital Elevation Models and Glacier Velocities
A Glacier Surge of Bivachny Glacier, Pamir Mountains, Observed by a Time Series of High-Resolution Digital Elevation Models and Glacier Velocities
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DOI：
10.3390/rs9040388
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发表时间：
2017-04
期刊：
影响因子：
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通讯作者：
A. Wendt;C. Mayer;A. Lambrecht;D. Floricioiu
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文献类型：
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作者：
A. Wendt;C. Mayer;A. Lambrecht;D. Floricioiu
涌动型冰川的特点是，在冰川实际上不活跃的相对较长的静止阶段之后，冰输送和质量重新分布增强的阶段相对较短。这种不稳定的行为使得评估气候变化对这些冰川的影响变得困难。我们描述了 2011 年至 2015 年间塔吉克斯坦帕米尔山区比瓦奇尼冰川最近一次激增的地形和动力学变化。对于相关时间跨度，从 TanDEM-X 数据导出了九个数字高程模型；使用光学卫星数据（Landsat 5、7和8、EO-1）以及合成孔径雷达数据（TerraSAR-X和TanDEM-X）来分析冰流速度。将涌流开始时的地形与 2000 年航天飞机雷达地形测量任务观测到的地形进行比较，发现冰川消融区域的上部变厚，而冰川下方则变薄，正如在静止阶段通常观察到的那样。在活动阶段，一个高达约 80 m 的涌浪形成，并向下游移动了 13 km 的距离，平均速度为 4400 m Year−1。冰流速度从 2000 年静止期的低于 90 myear−1 增至 2014 年春季的 3400 myear−1。到达与 Fedchenko 冰川交汇处后，冰流速度减慢，直到 2015 年完全终止。观测到的冰川速度季节性，在融化期开始时有规律地加速，表明对冰流的水文控制与冰流有效性相关。冰下排水系统。
Surge-type glaciers are characterised by relatively short phases of enhanced ice transport and mass redistribution after a comparatively long quiescent phase when the glacier is virtually inactive. This unstable behaviour makes it difficult to assess the influence of climate change on those glaciers. We describe the evolution of the most recent surge of Bivachny Glacier in the Pamir Mountains, Tajikistan between 2011 and 2015 with respect to changes in its topography and dynamics. For the relevant time span, nine digital elevation models were derived from TanDEM-X data; optical satellite data (Landsat 5, 7 and 8, EO-1) as well as synthetic aperture radar data (TerraSAR-X and TanDEM-X) were used to analyse ice flow velocities. The comparison of the topography at the beginning of the surge with the one observed by the Shuttle Radar Topography Mission in 2000 revealed a thickening in the upper part of the ablation area of the glacier and a thinning further down the glacier as is typically observed during the quiescent phase. During the active phase, a surge bulge measuring up to around 80 m developed and travelled downstream for a distance of 13 km with a mean velocity of 4400 m year−1. Ice flow velocities increased from below 90 m year−1 duringthe quiescent phase in 2000 to up to 3400 m year−1 in spring 2014. After reaching the confluence with Fedchenko Glacier, the surge slowed down until it completely terminated in 2015. The observed seasonality of the glacier velocities with a regular speed-up during the onset of the melt period suggests a hydrological control of the surge related to the effectiveness of the subglacial drainage system.