Flow localization in fissure eruptions
Flow localization in fissure eruptions
复制标题
裂缝喷发中的流动局部化
DOI：
10.1007/s004450050243
复制
发表时间：
1999
影响因子：
3.5
通讯作者：
J. Salzig
中科院分区：
文献类型：
--
作者：
J. Wylie;K. Helfrich;B. Dade;J. Lister;J. Salzig
摘要在玄武质裂隙喷发过程中，热岩浆向周围岩石的热传递导致岩浆粘度急剧增加，并在边缘凝固。 粘度差和固化都可以放大流速的初始变化，并导致沿裂缝走向沿着流动的局部化。然而，对于典型参数，由固化驱动的放大比由粘度变化驱动的放大慢且明显弱。事实上，对于检查的参数，由于固化的放大是如此之弱，它的效果几乎是微不足道的，而粘度变化提供了一个强大的流动局部化的积极机制。实验室实验说明粘性本地化，并建议这种机制是强大的。粘度对温度的依赖性可以引起岩浆房压力的微小变化，从而导致岩浆通过裂缝的流量大幅增加。
Abstract During a basaltic fissure eruption heat transfer from the hot magma to the surrounding rock causes a dramatic increase in the magmatic viscosity and solidification at the margins. Both viscosity contrast and solidification can amplify initial variations in the flow rate and lead to localization of the flow along the strike of the fissure. However, for typical parameters, amplification driven by solidification is slower and significantly weaker than amplification driven by viscosity variations. In fact, for the parameters examined, the amplification due to solidification is so weak that its effect is almost insignificant, whereas viscosity variation provides a strong active mechanism for flow localization. Laboratory experiments illustrate viscous localization and suggest that this mechanism is robust. The dependence of viscosity on temperature can cause a small change in the pressure of the magma chamber to lead to a large jump in the flow rate of magma through the fissure.