Seismogenic lavas and explosive eruption forecasting
Seismogenic lavas and explosive eruption forecasting
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DOI：
10.1038/nature06980
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发表时间：
2008-05-22
期刊：
影响因子：
64.8
通讯作者：
Kruhl, J. H.
中科院分区：
文献类型：
--
作者：
Lavallee, Y.;Meredith, P. G.;Kruhl, J. H.
火山圆顶建筑事件通常在爆发性喷发之前表现出溢出放电率和地震活动性的加速（1）。这将使材料失效预测方法能够应用于喷发预测（2，3）。到目前为止，这些方法完全基于围岩的地震活动性（4）。然而，很明显，熔岩的流变学和变形速率最终决定了喷发的类型（5）。这些喷发中涉及的高度结晶的熔岩是假塑性流体，当它们的变形在韧性到脆性的转变中加速时，它们表现出强烈的剪切变稀成分（6）。因此，了解圆顶熔岩的韧脆转变的性质可能是准确描述圆顶生长和稳定性的关键。在这里，我们提出的流变实验与连续微震监测的结果，这表明，圆顶熔岩是地震和地震活动性的字符显着变化的整个延性-脆性转变，直到完全脆性破坏发生在高应变率。我们的结论是，岩浆地震活动，结合故障预测方法，可能会成功地应用到圆顶建筑火山喷发预测。
Volcanic dome-building episodes commonly exhibit acceleration in both effusive discharge rate and seismicity before explosive eruptions(1). This should enable the application of material failure forecasting methods to eruption forecasting(2,3). To date, such methods have been based exclusively on the seismicity of the country rock(4). It is clear, however, that the rheology and deformation rate of the lava ultimately dictate eruption style(5). The highly crystalline lavas involved in these eruptions are pseudoplastic fluids that exhibit a strong component of shear thinning as their deformation accelerates across the ductile to brittle transition(6). Thus, understanding the nature of the ductile-brittle transition in dome lavas may well hold the key to an accurate description of dome growth and stability. Here we present the results of rheological experiments with continuous microseismic monitoring, which reveal that dome lavas are seismogenic and that the character of the seismicity changes markedly across the ductile-brittle transition until complete brittle failure occurs at high strain rates. We conclude that magma seismicity, combined with failure forecasting methods, could potentially be applied successfully to dome-building eruptions for volcanic forecasting.