Modelling pyroclastic density currents of the April 2021 La Soufrière, St Vincent eruption: from rapid invasion maps to field-constrained numerical simulations
Modelling pyroclastic density currents of the April 2021 La Soufrière, St Vincent eruption: from rapid invasion maps to field-constrained numerical simulations
复制标题
对 2021 年 4 月圣文森特拉苏弗里埃尔火山喷发的火山碎屑密度流进行建模：从快速入侵图到场约束数值模拟
DOI：
10.1144/sp539-2022-290
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Dualeh, Edna W.
中科院分区：
文献类型：
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作者：
Gueugneau, Valentin;Charbonnier, Sylvain;Miller, Victoria L.;Cole, Paul;Grandin, Raphaël;Dualeh, Edna W.
2021年4月的圣文森特拉苏弗里耶尔火山爆发在危机的两周内（4月9日至22日）产生了几个火山碎屑密度流（PDC）。为了在这次喷发期间支持危险评估小组，进行了真实的数值模拟，并使用两阶段版本的代码VolcFlow生成了基于Arabino的PDC入侵图，该代码能够模拟PDC的浓缩和稀释状态。为了生成地图，仅改变用于生成PDC的源属性（形状和位置）和初始体积，所有其他输入参数保持恒定并从先前的模拟中估计。新的模拟，然后进行基于现场的存款地图的基础上，以评估代码的能力，模拟这样的PDC。结果表明，同危机入侵地图令人满意地模仿所观察到的山谷局限的PDCs，而无约束稀释PDCs被高估。结果还强调，模拟结果大大改善了额外的基于字段的数据，这有助于约束PDC序列。吸取了许多经验教训，包括（1）如何选择最关键的输入参数，（2）同喷发雷达图像的重要性，以及（3）这种两阶段模型用于快速灾害评估的潜力。
The April 2021 La Soufrière of St Vincent eruption generated several pyroclastic density currents (PDCs) during the 2 weeks of the crisis, from 9 to 22 April. To support the hazard assessment team during this eruption, numerical simulations were performed in real time and generated rapid scenario-based PDC invasion maps with the two-phase version of the code VolcFlow, which was able to simulate both the concentrated and dilute regime of PDCs. To generate the maps, only the source properties (shape and location) and the initial volume used to generate the PDCs were varied, all other input parameters were kept constant and estimated from previous simulations. New simulations were then performed based on the field-based deposit map to assess the code's ability to simulate such PDCs. Results show that the syn-crisis invasion maps satisfactorily mimic the observed valley-confined PDCs, while unconfined dilute PDCs were overestimated. The results also highlight that simulation results are greatly improved with additional field-based data, which help constrain the PDC sequence. Numerous lessons were learned, including (1) how to choose the most critical input parameters,(2) the importance of syn-eruptive radar imagery and (3) the potential of this two-phase model for rapid hazard assessment purposes.