In 2012, the eruption of deep-sea volcano Havre produced an abundance of fine ash at a depth of ~ 1000 m below sea level. In this study the 2D shapes of Havre ash grains retrieved from the seafloor were compared quantitatively with those of particles generated in a suite of different fragmentation experiments, which used remelted rhyolitic rock and pumice from the eruption site. A new statistical data analysis technique, denoted as Dendrogrammatic Analysis of Particle Morphology (DAPM) is introduced. It is designed to compare large numbers of morphometric data sets containing shape information for a set of ash particles to group them by morphological similarities and to visualize these clusters in a dendrogram. Further steps involve t tests and equivalence tests and reveal morphometric differences as well as matching features. The DAPM suggests that the majority of Havre ash was thermohydraulically produced by induced fuel coolant-interaction. A subset of ash particles features an elongated tube morphology. Their morphometry matches that of particles that were experimentally produced by a combination of shearing and quenching, and we infer that the natural particles were formed by synextrusive ash-venting.

中文翻译：

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通过粒子形态测量的树状图分析揭示了哈弗尔的深海破碎样式

2012 年，深海火山 Havre 的喷发在海平面以下约 1000 米的深度产生了大量的细灰。在这项研究中，从海底回收的哈佛火山灰颗粒的二维形状与一系列不同破碎实验中产生的颗粒进行了定量比较，这些颗粒使用来自喷发地点的重熔流纹岩和浮石。介绍了一种新的统计数据分析技术，称为粒子形态学树形图分析 (DAPM)。它旨在比较包含一组灰颗粒形状信息的大量形态测量数据集，以按形态相似性对它们进行分组，并在树状图中可视化这些集群。进一步的步骤涉及 t 检验和等价检验，并揭示形态测量差异以及匹配特征。DAPM 表明，大部分 Havre 灰分是通过诱导燃料冷却剂相互作用以热液压方式产生的。一部分灰颗粒具有细长的管状形态。它们的形态测量与通过剪切和淬火组合实验产生的颗粒相匹配，我们推断天然颗粒是通过同步喷灰形成的。