High‐latitude rivers are commonly covered by ice for up to one third of the year. Our understanding of the effects of ice on channel morphodynamics and bedload transport is hindered by the difficulties of sensing through the ice and dangers of field work on thin ice or during ice break‐up. To avoid this drawback, we used seismic signals to interpret processes and quantify water and sediment fluxes. Our objective was to determine seasonal differences in hydraulics and bedload sediment transport under ice‐covered versus open‐channel flow conditions using a small seismic network and to provide a first‐order estimation of sediment flux in a Fennoscandian river. Our study reach was on a straight, low‐gradient section of the Sävar River in northern Sweden. Interpretations of seismic signals, from a station 40 m away from the river, and inverted physical models of river stage and bedload flux indicate clear seasonal differences between ice‐covered and open‐channel flow conditions. Diurnal cycles in seismic signals reflecting turbulence and sediment transport are evident directly after ice break‐up. Analysis of seismic signals of ice‐cracking support our visual interpretation of ice break‐up timing and the main ice break‐up mechanism as thermal rather than mechanical. Assuming the bulk of sediment moves during ice break‐up and the snowmelt flood, we calculate a minimum annual sediment flux of 56.2 ± 0.7 t/km², which drastically reduces the uncertainty from previous estimates (0–50 t/km²) that exclude ice‐covered or ice break‐up periods.

中文翻译：

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北极河的地震监测：水力，泥沙输送和冰动力学的季节性变化

高纬度河流通常长达一年的三分之一被冰覆盖。我们对冰对通道形态动力学和床载运输的影响的理解受到阻碍，因为难以通过冰进行检测以及在薄冰上或在冰破裂过程中进行野外作业的危险。为避免此缺点，我们使用地震信号来解释过程并量化水和泥沙通量。我们的目标是使用小型地震网络确定冰雪条件下与明渠水流条件下水力和床荷输沙量的季节性差异，并对芬诺斯堪的纳维亚河流的泥沙通量进行一级估算。我们的研究范围位于瑞典北部的萨瓦河（SävarRiver）平直的低坡段。距河40 m处的地震信号的解释，河流水位和河床通量的反演物理模型表明，冰覆盖和明渠水流条件之间存在明显的季节性差异。冰破裂后，地震信号中反映湍流和沉积物传输的昼夜周期很明显。对裂冰地震信号的分析支持了我们对破冰时间和主要破冰机理的热力学而非机械视觉解释。假设在冰破裂和融雪洪水期间大量泥沙运动，我们计算出的最小年度泥沙通量为56.2±0.7 t / km 对裂冰地震信号的分析支持了我们对破冰时间和主要破冰机理的热力学而非机械视觉解释。假设在冰破裂和融雪洪水期间大量泥沙运动，我们计算出的最小年度泥沙通量为56.2±0.7 t / km 对裂冰地震信号的分析支持了我们对破冰时间和主要破冰机制为热而非机械的可视化解释。假设在冰破裂和融雪洪水期间大量泥沙运动，我们计算出的最小年度泥沙通量为56.2±0.7 t / km²，这大大减少了先前估计值（0-50 t / km ²）的不确定性，该不确定性排除了冰雪覆盖或冰破裂的时期。