The cross-sectional profile of a glacial valley can be obtained with a variational principle in which the friction against the valley walls and the glacier bed is extremized, subject to a Lagrangian constraint. We show that the actual valley profile maximizes the friction, thus settling an old debate.

中文翻译：

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最大限度地增加冰川谷侵蚀中的摩擦力

冰川谷的横截面轮廓可以通过变分原理获得，其中谷壁和冰川床的摩擦力受到拉格朗日约束。我们展示了实际的山谷轮廓最大化摩擦，从而解决了一个古老的争论。