Using infrasound to constrain ash plume rise
Using infrasound to constrain ash plume rise
复制标题
利用次声抑制灰羽上升
DOI：
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发表时间：
2015
影响因子：
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通讯作者：
Y. Lavallée
中科院分区：
文献类型：
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作者：
O. Lamb;S. De Angelis;Y. Lavallée
目前，空中火山灰的建议是基于对时间分辨率相对较低的卫星图像的分析，以及对大气羽流扩散的数值模拟。这些模拟依赖于关键的输入参数，如喷发羽流的最大高度和喷口的质量喷发速率，这些参数仍然受到松散的限制。在这项研究中，我们提出了一种概念验证工作流程，将火山次声分析与真实大气中火山羽流上升的数值模拟相结合。我们分析了2009年火山喷发期间两次爆炸的次声记录。美国堡垒，产生了高达12-14公里的羽流。我们在线性声学理论的假设下模拟了声源的次声辐射，并计算了喷口质量抛射速度的变化。估计的喷发速度作为羽流上升的数值模式的输入。令人鼓舞的结果突出了将次声测量纳入火山灰扩散的数值模型的可能性，并确认了它们对火山监测作业的价值。
Airborne volcanic ash advisories are currently based on analyses of satellite imagery with relatively low temporal resolution, and numerical simulations of atmospheric plume dispersion. These simulations rely on key input parameters such as the maximum height of eruption plumes and the mass eruption rate at the vent, which remain loosely constrained. In this study, we present a proof-of-concept workflow that incorporates the analysis of volcanic infrasound with numerical modelling of volcanic plume rise in a realistic atmosphere. We analyse acoustic infrasound records from two explosions during the 2009 eruption of Mt. Redoubt, USA, that produced plumes reaching heights of 12–14 km. We model the infrasonic radiation at the source under the assumptions of linear acoustic theory and calculate variations in mass ejection velocity at the vent. The estimated eruption velocities serve as the input for numerical models of plume rise. The encouraging results highlight the potential for infrasound measurements to be incorporated into numerical modelling of ash dispersion, and confirm their value for volcano monitoring operations.