The effects of entrained debris on the basal sliding stability of a glacier
The effects of entrained debris on the basal sliding stability of a glacier
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夹带碎片对冰川基底滑动稳定性的影响
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
M. Jackson
中科院分区：
文献类型：
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作者：
L. Zoet;B. Carpenter;M. Scuderi;R. Alley;S. Anandakrishnan;C. Marone;M. Jackson
探索可能的冰下条件的新实验室实验揭示了对岩石上充满碎片的冰的稳定滑动和粘滑运动之间过渡的控制，并对冰川行为产生影响。岩石基底和冰中的碎屑之间的摩擦产生热量，融化附近的冰产生润滑水。滑动速度的增加或夹带的碎片的增加会增加热量的产生，从而增加融水的产生。不稳定滑动是有利的低初始润滑，然后快速融水生产响应速度增加。低初始润滑可能是由于冷或排水条件，而快速增加的融水产生的结果，由高滑动速度或高碎片负载引起的强烈摩擦加热。加强的接口（愈合）在“坚持”之间的滑动事件的间隔发生主要是通过融水再冻结。当愈合和不稳定滑动一起考虑时，这里报告的实验表明，粘滑行为在基岩上的碎片冰川冰运动中很常见。
New laboratory experiments exploring likely subglacial conditions reveal controls on the transition between stable sliding and stick‐slip motion of debris‐laden ice over rock, with implications for glacier behavior. Friction between a rock substrate and clasts in ice generates heat, which melts nearby ice to produce lubricating water. An increase in sliding speed or an increase in entrained debris raises heat generation and thus meltwater production. Unstable sliding is favored by low initial lubrication followed by rapid meltwater production in response to a velocity increase. Low initial lubrication can result from cold or drained conditions, whereas rapid increase in meltwater generation results from strong frictional heating caused by high sliding velocity or high debris loads. Strengthening of the interface (healing) during “stick” intervals between slip events occurs primarily through meltwater refreezing. When healing and unstable sliding are taken together, the experiments reported here suggest that stick‐slip behavior is common from motion of debris‐laden glacier ice over bedrock.