Relation Between Water Drainage and Short-term Strain/velocity Events on Storglaciaren, Sweden, and Geomorphic Implications

在瑞典北部的一个以温带为主的山谷冰川——斯托洛冰川的床上有一个过度加深的现象。在过深的冰川中，至少在局部，被一层水饱和的可变形土层所覆盖，冰川排水系统是冰封的，水压一直很高。在这里，水输入的日变化似乎导致了地下水位长而低的波动。当这些波向冰川下方移动时，它们似乎会被放大，从而导致冰川表面的局部昼夜隆起。在冰川下，从过深的排水是冰下的，水压有很大的日变化（通常为7b）。在这里，峰值流速似乎出现在上升和下降的水压期间，而不是在峰值压力期间。将进行示踪实验和测量地表倾斜、应变、速度、内部变形和水压来研究这些现象。预计这些结果不仅会澄清它们的原因，而且还有助于对冰川对水压变化的反应的一般理解。研究结果还有望为冰川地质学的一个经典问题提供线索：冰川层的旋转和过度加深的起源。作为研究这个问题的一部分，一名博士后助理研究员将调查冰川采石的过程。

There is an overdeepening in the bed of Storglaciaren, a predominantly temperate valley glacier in northern Sweden. In the overdeepening the glacier is, at least locally, underlain by a layer of water-saturated deformable till, the glacial drainage system is englacial, and water pressures are consistently high. Here also, diurnal variations in water input appear to result in long, low waves in the water table. These waves seem to become amplified as they move downglacier, resulting in a local diurnal uplift of the glacier surface. Downglacier from the overdeepening the drainage is subglacial and there are large (often 7 b) diurnal variations in water pressure. Here, peak velocities seem to occur during rising and falling water pressures, rather than during the peak pressure. Tracer experiments and measurements of surface tilt, strain, velocity, internal deformation, and water pressure will be undertaken to study these phenomena. The results are expected to not only clarify their causes, but also to contribute to a general understanding of the response of glaciers to variations in water pressure. The results are also expected to shed light in a classical problem of glacial geology: the origin of cirques and overdeepening in glacier beds. As part of the study of this problem, a post- doctoral research associate will be investigating processes of glacial quarrying.