Changes in Crater Geometry Revealed by Inversion of Harmonic Infrasound Observations: 24 December 2018 Eruption of Mount Etna, Italy
Changes in Crater Geometry Revealed by Inversion of Harmonic Infrasound Observations: 24 December 2018 Eruption of Mount Etna, Italy
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DOI：
10.1029/2020gl088077
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发表时间：
2020-10-16
影响因子：
5.2
通讯作者：
Cannata, Andrea
中科院分区：
文献类型：
--
作者：
Watson, Leighton M.;Johnson, Jeffrey B.;Cannata, Andrea
2018年12月，埃特纳火山（意大利）经历了一段喷发活动增加的时期，最终导致东南侧的裂缝喷发。侧突发作后，峰值次声信号的峰值频率降低，共振增强。我们反转次声观测火山口的几何形状，并表明火山口的深度和半径增加，在喷发过程中，这表明侧翼喷发排出岩浆从峰会和喷发活动导致火山口壁的侵蚀。通过反演整个次声振幅谱而不仅仅是峰值频率，我们能够对陨石坑的几何形状施加额外的约束，并反演陨石坑的形状，而不是假设陨石坑的形状。这项工作说明了谐波次声观测可以用来获得高时间分辨率的信息火山口的几何形状，并可以限制复杂的过程中发生的人迹罕至的火山口地区在喷发活动。
In December 2018, Mount Etna (Italy) experienced a period of increased eruptive activity that culminated in a fissure eruption on the southeast flank. After the onset of the flank eruption, the peak frequency of the summit infrasound signals decreased while resonance increased. We invert infrasound observations for crater geometry and show that crater depth and radius increased during the eruption, which suggests that the flank eruption drained magma from the summit and that eruptive activity led to erosion of the crater wall. By inverting the entire infrasound amplitude spectra rather than just the peak frequency, we are able to place additional constraints on the crater geometry and invert for, rather than assume, the crater shape. This work illustrates how harmonic infrasound observations can be used to obtain high-temporal-resolution information about crater geometry and can place constraints on complex processes occurring in the inaccessible crater region during eruptive activity.