The Elusive Evidence of Volcanic Lightning.
The Elusive Evidence of Volcanic Lightning.
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DOI：
10.1038/s41598-017-15643-8
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发表时间：
2017-11-14
影响因子：
4.6
通讯作者：
Mazzola M
中科院分区：
文献类型：
--
作者：
Genareau K;Gharghabi P;Gafford J;Mazzola M
众所周知，雷击会在形态上改变和化学上减少地质构造和沉积物，形成闪电岩。类似的过程发生在火山闪电放电的结果，当空气中的火山灰转化为闪电诱发的火山小球（LIVS）时。在这里，我们适应在以前的研究中使用的计算雷电引起的基础设施材料的损坏，以确定对伪灰样品的简化组成的影响。使用实验室高电流脉冲实验，这项研究表明，在闪电放电通道内有一个理想的熔化区，约占总通道半径的10%或更少，在此温度足以熔化灰烬，无论峰值电流如何。熔化的灰同时被加热的膨胀空气从通道中排出，允许颗粒在大气传输期间冷却，然后停留在灰落沉积物中。这个理想的熔化区的有限大小解释了通常在火山灰中观察到的LIVS数量很少，尽管在爆炸性喷发期间经常发生闪电。
Lightning strikes are known to morphologically alter and chemically reduce geologic formations and deposits, forming fulgurites. A similar process occurs as the result of volcanic lightning discharge, when airborne volcanic ash is transformed into lightning-induced volcanic spherules (LIVS). Here, we adapt the calculations used in previous studies of lightning-induced damage to infrastructure materials to determine the effects on pseudo-ash samples of simplified composition. Using laboratory high-current impulse experiments, this research shows that within the lightning discharge channel there is an ideal melting zone that represents roughly 10% or less of the total channel radius at which temperatures are sufficient to melt the ash, regardless of peak current. The melted ash is simultaneously expelled from the channel by the heated, expanding air, permitting particles to cool during atmospheric transport before coming to rest in ash fall deposits. The limited size of this ideal melting zone explains the low number of LIVS typically observed in volcanic ash despite the frequent occurrence of lightning during explosive eruptions.
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影响因子：
5.2
作者：
Cimarelli, C.;Alatorre-Ibarguengoitia, M. A.;Dingwell, D. B.
通讯作者：
Dingwell, D. B.
影响因子：
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通讯作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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