Thermomechanical controls on magma supply and volcanic deformation: application to Aira caldera, Japan
Thermomechanical controls on magma supply and volcanic deformation: application to Aira caldera, Japan
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DOI：
10.1038/srep32691
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发表时间：
2016-09-13
影响因子：
4.6
通讯作者：
Iguchi, Masato
中科院分区：
文献类型：
--
作者：
Hickey, James;Gottsmann, Joachim;Iguchi, Masato
地表变形往往先于火山爆发，是震源过程和周围岩石热机械行为之间复杂相互作用的结果。以前的模型，旨在限制源过程无法包括现实的力学和热岩石性质，热力学的不均匀性在岩浆聚集的作用是不清楚的。在这里，我们展示了如何时空变形和岩浆储层的演化从根本上控制的三维热-力学的不均匀性。以日本Aira火山口持续膨胀为例，我们证明了岩浆积累的速度比喷发的速度要快，目前的抬升正在接近1914年普林尼火山爆发前的水平。岩浆储存条件与29，000年前的火山口形成水库的估计相吻合，推断的岩浆供应率表明类似于130年的时间框架，以积累足够的岩浆来满足未来1914年规模的喷发。这些新的推论是重要的火山喷发预测和风险缓解，并具有重要意义的解释火山变形世界各地。
Ground deformation often precedes volcanic eruptions, and results from complex interactions between source processes and the thermomechanical behaviour of surrounding rocks. Previous models aiming to constrain source processes were unable to include realistic mechanical and thermal rock properties, and the role of thermomechanical heterogeneity in magma accumulation was unclear. Here we show how spatio-temporal deformation and magma reservoir evolution are fundamentally controlled by three-dimensional thermomechanical heterogeneity. Using the example of continued inflation at Aira caldera, Japan, we demonstrate that magma is accumulating faster than it can be erupted, and the current uplift is approaching the level inferred prior to the violent 1914 Plinian eruption. Magma storage conditions coincide with estimates for the caldera-forming reservoir similar to 29,000 years ago, and the inferred magma supply rate indicates a similar to 130-year timeframe to amass enough magma to feed a future 1914-sized eruption. These new inferences are important for eruption forecasting and risk mitigation, and have significant implications for the interpretations of volcanic deformation worldwide.