Application of Constitutive Friction Laws to Glacier Seismicity
Application of Constitutive Friction Laws to Glacier Seismicity
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DOI：
10.1029/2020gl088964
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发表时间：
2020-10
影响因子：
5.2
通讯作者：
L. Zoet;M. Ikari;R. Alley;C. Marone;S. Anandakrishnan;B. Carpenter;M. Scuderi
中科院分区：
文献类型：
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作者：
L. Zoet;M. Ikari;R. Alley;C. Marone;S. Anandakrishnan;B. Carpenter;M. Scuderi
虽然冰川地震活动的分析仍然是解释冰川过程的广泛使用的方法，但控制冰川粘滑地震活动的基本机制仍然是推测性的。在这里，我们报告了在精心控制的条件下，载满碎片的冰滑过基岩粗糙体的实验室剪切实验。通过改变弹性加载刚度，我们产生了第一个实验室冰震。我们的工作代表了不稳定冰滑事件的第一次全面的实验室观测，并复制了冰川滑动的几个地震现场观测，如滑动速度，应力降以及应力降与复发间隔之间的关系。我们还观察到，粘滑在临界驱动速度以上开始，并且应力降大小随着速度的进一步增加而减小，这与摩擦理论和岩石对岩石摩擦实验室实验一致。我们的研究结果表明，冰川滑动行为可以准确地预测本构速率和状态摩擦定律，开发岩石摩擦。
While analysis of glacial seismicity continues to be a widely used method for interpreting glacial processes, the underlying mechanics controlling glacial stick‐slip seismicity remain speculative. Here, we report on laboratory shear experiments of debris‐laden ice slid over a bedrock asperity under carefully controlled conditions. By modifying the elastic loading stiffness, we generated the first laboratory icequakes. Our work represents the first comprehensive lab observations of unstable ice‐slip events and replicates several seismological field observations of glacier slip, such as slip velocity, stress drop, and the relationship between stress drop and recurrence interval. We also observe that stick‐slips initiate above a critical driving velocity and that stress drop magnitude decreases with further increases in velocity, consistent with friction theory and rock‐on‐rock friction laboratory experiments. Our results demonstrate that glacier slip behavior can be accurately predicted by the constitutive rate‐and‐state friction laws that were developed for rock friction.