Glacier basal motion is responsible for the majority of ice flux on fast-flowing glaciers, enables rapid changes in glacier motion and provides the means by which glaciers shape alpine landscapes. In an effort to enhance our understanding of basal motion, we investigate the evolution of glacier velocity and ice-marginal lake stage on Kennicott Glacier, Alaska, during the spring–summer transition, a time when subglacial drainage is undergoing rapid change. A complicated record of > 50 m fill-and-drain sequences on a hydraulically-connected ice-marginal lake likely reflects the punctuated establishment of efficient subglacial drainage as the melt season begins. The rate of change of lake stage generally correlates with diurnal velocity maxima, both in timing and magnitude. At the seasonal scale, the up-glacier progression of enhanced summer basal motion promotes uniformity of daily glacier velocity fluctuations throughout the 10 km study reach, and results in diurnal velocity patterns suggesting increasingly efficient meltwater delivery to and drainage from the subglacial channel system. Our findings suggest the potential of using an ice-marginal lake as a proxy for subglacial water pressure, and show how widespread basal motion affects bulk glacier behavior.

中文翻译：

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冰缘湖泊水文和阿拉斯加肯尼科特冰川的季节动态演化

冰川基底运动是快速流动冰川上大部分冰通量的原因，使冰川运动发生快速变化，并为冰川塑造高山景观提供了手段。为了加强我们对基础运动的理解，我们研究了阿拉斯加肯尼科特冰川在春夏过渡期间冰川速度和冰缘湖阶段的演变，此时冰下排水正在快速变化。在水力连接的冰缘湖上，> 50 m 的注水和排水序列的复杂记录可能反映了随着融化季节开始时有效冰下排水的断断续续建立。湖泊水位的变化率通常与日流速最大值相关，无论是在时间上还是在幅度上。在季节尺度上，夏季基础运动增强的冰川向上进展促进了整个 10 公里研究范围内每日冰川速度波动的均匀性，并导致日速度模式表明越来越有效的融水输送到冰下通道系统并从冰下通道系统排出。我们的研究结果表明使用冰缘湖作为冰下水压代理的潜力，并显示广泛的基底运动如何影响大块冰川的行为。