Glacier-erosion rates range across orders of magnitude, and much of this variation cannot be attributed to basal sliding rates. Subglacial till acts as lubricating ‘fault gouge’ or ‘sawdust’, and must be removed for rapid subglacial bedrock erosion. Such erosion occurs especially where and when moulin-fed streams access the bed and are unconstrained by supercooling or other processes. Streams also may directly erode bedrock, likely with strong time-evolution. Erosion is primarily by quarrying, aided by strong fluctuations in the water system driven by variable surface melt and by subglacial earthquakes. Debris-bed friction significantly affects abrasion, quarrying and general glacier flow. Frost heave drives cirque headwall erosion as winter cold air enters bergschrunds, creating temperature gradients to drive water flow along premelted films to growing ice lenses that fracture rock, and the glacier removes the resulting blocks. Recent subglacial bedrock erosion and sediment flux are in many cases much higher than long-term averages. Over glacial cycles, evolution of glacial-valley form feeds back strongly on erosion and deposition. Most of this is poorly quantified, with parts open to argument. Glacial erosion and interactions are important to tectonic and volcanic processes as well as climate and biogeochemical fluxes, motivating vigorous research.

中文翻译：

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冰川侵蚀：现状与展望

冰川侵蚀速率的范围跨越多个数量级，其中大部分变化不能归因于基础滑动速率。冰下刨床起到润滑“断层凿”或“锯末”的作用，必须去除冰下基岩的快速侵蚀。这种侵蚀尤其发生在红磨坊进料流进入床并且不受过冷或其他过程限制的地方和时间。溪流也可能直接侵蚀基岩，可能伴随着强烈的时间演化。侵蚀主要是通过采石活动，在水系统中由可变的地表融化和冰下地震驱动的强烈波动的帮助下。碎屑床摩擦显着影响磨损、采石和一般冰川流动。随着冬季冷空气进入 bergschrunds，冻胀推动了圆环顶壁的侵蚀，产生温度梯度，推动水流沿着预先融化的薄膜流向生长的冰透镜，使岩石破裂，冰川将由此产生的冰块移走。最近的冰下基岩侵蚀和沉积物通量在许多情况下远高于长期平均值。在冰河周期中，冰河谷形态的演化强烈反馈侵蚀和沉积。其中大部分都没有量化，部分内容有待商榷。冰川侵蚀和相互作用对构造和火山过程以及气候和生物地球化学通量很重要，激发了积极的研究。冰川谷形态的演化强烈地反馈侵蚀和沉积。其中大部分都没有量化，部分内容有待商榷。冰川侵蚀和相互作用对构造和火山过程以及气候和生物地球化学通量很重要，激发了积极的研究。冰川谷形态的演化强烈地反馈侵蚀和沉积。其中大部分都没有量化，部分内容有待商榷。冰川侵蚀和相互作用对构造和火山过程以及气候和生物地球化学通量很重要，激发了积极的研究。