Characterizing Sediment Flux of Deforming Glacier Beds
Characterizing Sediment Flux of Deforming Glacier Beds
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DOI：
10.1029/2021jf006544
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发表时间：
2022-03
期刊：
影响因子：
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通讯作者：
D. Hansen;L. Zoet
中科院分区：
文献类型：
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作者：
D. Hansen;L. Zoet
基本滑移期间的亚冰淇淋的变形会形成许多快速流动的冰川和冰流的床会影响冰川动力学和亚冰分侵蚀的速度，但在多个时间范围内，它的基本依赖性却没有很好地对造成效果。使用数字图像从止床的摄影时间序列中，我们发现沉积物通量和滑动速度之间的关系近乎线性，但是在有效的压力上，沉积物通量的非单调，双重依赖性依赖性，主要是在冰鞋附近的薄剪切带中发生的。
Deformation of subglacial sediment during basal slip shapes the beds of many fast‐flowing glaciers and ice streams. The resultant sediment flux impacts glacier dynamics and rates of subglacial erosion over a range of timescales, but its fundamental dependencies are not well understood. Using a cryogenic ring shear device, we conducted experiments to investigate the effects of both effective stress and slip speed on rates of till transport. Sediment fluxes were computed using digital image correlation from a photographic time series of the till bed. We find a near‐linear relationship between sediment flux and slip speed, but a non‐monotonic, double‐valued dependency of sediment flux on effective stress. Deformation primarily occurred in a thin shear band near the ice sole, the thickness of which could vary with both parameters. Coupling between ice and till increased at higher slip speeds and effective stresses and scaled the magnitude of the flow profile.