Rapidly-rising jökulhlaups, or glacial outburst floods, are a phenomenon with a high potential for damage. The initiation and propagation processes of a rapidly-rising jökulhlaup are still not fully understood. Seismic monitoring can contribute to an improved process understanding, but comprehensive long-term seismic monitoring campaigns capturing the dynamics of a rapidly-rising jökulhlaup have not been reported so far. To fill this gap, we installed a seismic network at the marginal, ice-dammed lake of the A.P. Olsen Ice Cap (APO) in NE-Greenland. Episodic outbursts from the lake cause flood waves in the Zackenberg river, characterized by a rapid discharge increase within a few hours. Our 6 months long seismic dataset comprises the whole fill-and-drain cycle of the ice-dammed lake in 2012 and includes one of the most destructive floods recorded so far for the Zackenberg river. Seismic event detection and localization reveals abundant surface crevassing and correlates with changes of the river discharge. Seismic interferometry suggests the existence of a thin basal sedimentary layer. We show that the ballistic part of the first surface waves can potentially be used to infer medium changes in both the ice body and the basal layer. Interpretation of time-lapse interferograms is challenged by a varying ambient noise source distribution.

中文翻译：

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格陵兰岛 AP 奥尔森冰盖快速上升的 jökulhlaup 旋回的地震特征

快速上升的 jökulhlaups 或冰川爆发洪水是一种具有很高破坏潜力的现象。快速上升的 jökulhlaup 的启动和传播过程仍未完全了解。地震监测有助于提高对过程的理解，但迄今为止尚未报道全面的长期地震监测活动，以捕捉快速上升的 jökulhlaup 的动态。为了填补这一空白，我们在格陵兰岛东北部的 AP 奥尔森冰帽 (APO) 的边缘冰坝湖上安装了一个地震台网。湖中的突发性突发事件导致扎肯伯格河发生洪水，其特点是数小时内流量迅速增加。我们长达 6 个月的地震数据集包括 2012 年冰坝湖的整个注水循环，包括迄今为止记录的 Zackenberg 河最具破坏性的洪水之一。地震事件检测和定位揭示了丰富的地表裂缝，并与河流流量的变化相关。地震干涉测量表明存在薄的基底沉积层。我们表明，第一个表面波的弹道部分可以潜在地用于推断冰体和基底层的介质变化。延时干涉图的解释受到环境噪声源分布变化的挑战。地震干涉测量表明存在薄的基底沉积层。我们表明，第一个表面波的弹道部分可以潜在地用于推断冰体和基底层的介质变化。延时干涉图的解释受到环境噪声源分布变化的挑战。地震干涉测量表明存在薄的基底沉积层。我们表明，第一个表面波的弹道部分可以潜在地用于推断冰体和基底层的介质变化。延时干涉图的解释受到环境噪声源分布变化的挑战。