The Hispar Glacier is a useful site for studying surge mechanisms. Prior to this study, only two‐dimensional (2‐D) flow velocities having low temporal resolution were available for this glacier, providing inadequate information about its surge evolution. In this study, 139 synthetic aperture radar (SAR) images from Sentinel‐1A were used to obtain 3‐D flow velocity time series for the Hispar Glacier during the recent surge (2014–2016). The 3‐D flow velocities were sampled at an interval of 11 days, which is much greater than in previous studies. Besides, the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) and two TanDEM‐X images were used to determine glacier thickness changes prior to and following the recent surge. Combining the results and geomorphologic features, we deduced that the recent surge was because of saturated basal water pressure in the Yutmaru tributary. The mass from the Yutmaru tributary squeezed into the trunk and rapidly flowed downslope along the northern margin, generating strong normal pressure to the trunk mass. Pushed by the Yutmaru tributary, the trunk began to surge in September 2014. The flow velocity reached a first peak in May 2015 and then decreased in October 2015, as part of the basal meltwater ran off. However, basal meltwater accumulated again during the following 4 months, and correspondingly, the trunk accelerated again after October 2015. Finally, as kinetic energy was released and resisting force increased, the trunk became almost stagnant in August 2016. The surge mass was blocked downstream in the trunk by the mass transferred from the Kunyang tributary, and consequently, the glacier did not advance.

中文翻译：

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喀喇昆仑中部Hispar冰川的浪潮：SAR 3‐D流速时间序列和厚度变化

Hispar冰川是研究浪涌机制的有用站点。在此研究之前，该冰川仅具有低时间分辨率的二维（2D）流速，无法提供有关其浪涌演化的足够信息。在本研究中，使用了Sentinel-1A的139个合成孔径雷达（SAR）图像来获得近期激增期（2014-2016年）Hispar冰川的3D流速时间序列。以11天为间隔对3D流速进行采样，这比以前的研究要大得多。此外，航天飞机雷达地形任务（SRTM）数字高程模型（DEM）和两幅TanDEM-X图像用于确定近期潮汐前后的冰川厚度变化。结合结果和地貌特征，我们推断，最近的激增是由于Yutmaru支流中饱和的基础水压所致。Yutmaru支流的团块挤入主干，并迅速沿北缘向下倾斜，对主干团产生强大的常压。在尤特马鲁支流的推动下，该干线于2014年9月开始激增。流速随着基础熔体水的一部分流失，于2015年5月达到第一个峰值，然后于2015年10月下降。然而，基础熔体水在接下来的4个月中再次积聚，相应地，树干在2015年10月之后再次加速。最后，随着动能的释放和阻力的增大，树干在2016年8月几乎停滞。浪涌质量被下游阻塞从昆阳支流传来的树干中，