The Condition of Eruption Column Collapse: 1. A Reference Model Based on Analytical Solutions
The Condition of Eruption Column Collapse: 1. A Reference Model Based on Analytical Solutions
复制标题
喷发柱塌陷的条件：1.基于解析解的参考模型
DOI：
10.1029/2017jb015308
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Suzuki Yujiro J.
中科院分区：
文献类型：
--
作者：
Koyaguchi Takehiro;Suzuki Yujiro J.
喷发柱塌陷产生火山碎屑流的临界条件（柱塌陷条件）通常取决于岩浆性质、火山口形状（半径、深度和张角）以及通过火山管道的岩浆供应速率。在这里，我们基于一维（1-D）喷发柱模型和准一维管道流模型的解析解，提出了柱塌陷条件的参考模型，该模型考虑了火山口的影响。在参考模型中，柱塌陷条件由无量纲参数空间中的单个表面表示，与火山口底部的岩浆排放速率、岩浆供应速率（单位面积）以及火山口顶部和底部的横截面积之比有关。柱塌陷条件对岩浆性质的依赖性包含在这些无量纲参数的归一化因子中。先前的柱塌陷条件标准基于含水量与岩浆排放速率之间以及岩浆排放速率与火山口半径之间的关系，被视为当前参考模型的一部分或投影。该参考模型提供了一个框架，用于全面分析导致爆炸性喷发期间柱体倒塌的各种情况。
The critical condition at which an eruption column collapses to generate a pyroclastic flow (the column collapse condition) generally depends on magmatic properties, crater shape (radius, depth, and opening angle), and the magma supply rate through the volcanic conduit. Here we propose a reference model for the column collapse condition based on analytical solutions of a one‐dimensional (1‐D) eruption column model and a quasi‐1‐D conduit flow model, which considers the effects of the crater. In the reference model, the column collapse condition is expressed by a single surface in a dimensionless parameter space related to magma discharge rate, magma supply rate (per unit area) at the crater base, and the ratio of the cross‐sectional areas at the top and base of the crater. The dependence of the column collapse condition on magmatic properties is included in the normalization factors of these dimensionless parameters. Previous criteria for the column collapse condition, which were based on the relationship between water content and magma discharge rate and that between magma discharge rate and crater radius, are regarded as part of, or a projection of, the present reference model. The reference model provides a framework for a comprehensive analysis of the diverse scenarios resulting in column collapse during explosive eruptions.