Effect of solidification on a propagating dike.
Effect of solidification on a propagating dike.
复制标题
凝固对扩展堤的影响。
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
S. Tait
中科院分区：
文献类型：
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作者：
B. Taisne;S. Tait
[1]岩浆通过水力裂缝或岩脉的传播从深部穿过脆性地壳迁移。火山爆发发生在最后阶段，如果和当一个蔓延的岩墙到达表面。岩脉扩展涉及复杂的物理过程，因为同时发生的几个过程，如岩浆的粘性流动，岩石破裂，寄主岩石的弹性变形，以及岩浆物理性质（结晶，脱气，固化等）的潜在大的变化。目前，在现场或在现场测量方面，在岩浆到达地表之前跟踪岩浆迁移的最实用的方法是分析所产生的地震活动;然而，缺乏将岩脉中的岩浆流量与地震活动定量联系起来的物理模型。我们在这里提出的实验室实验涉及的流体填充裂纹的传播，使流体凝固后，与冷弹性主机接触。我们表明，这可以导致一种方法来估计作为表面创建率的函数的注入的通量。后者被证明是一个更可靠的衡量岩浆流量比向上传播的速度。在传播岩脉的地质应用中，表面区域的产生速率可能与地震能量的释放速率有关。虽然后者的关系需要进一步的工作是定量可靠的，但我们的新模型表明如何构建一个新的一般框架。
[1] Magma migration through the brittle crust from depth occurs by the propagation of hydraulic fractures or dikes. Volcanic eruptions occur at the last stage if and when a propagating dike reaches the surface. Dike propagation involves complex physics because of several processes that are simultaneously occurring such as viscous flow of magma, rock fracture, elastic deformation of the host rock, and potentially large changes of the physical properties of the magma (crystallization, degassing, solidification, etc.). Currently the most practical way in the field or in terms of field measurements to follow the migration of magma before it reaches the surface is the analysis of the seismicity generated; nevertheless, a physical model that quantitatively relates the flux of magma in the dike to the seismicity is lacking. We present here laboratory experiments involving propagation of a fluid-filled crack such that the fluid solidifies upon contact with the cold elastic host. We show that this can lead to a way of estimating the flux of the injection as a function of the surface creation rate. The latter is shown to be a more reliable gauge of magma flux than the upward propagating velocity. In the geologic application of a propagating dike, the rate of creation of surface area may be related to the rate of release of seismic energy. Although this latter relation needs further work to be quantitatively reliable, our new model nevertheless indicates how a new general framework can be constructed.