...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Volcanology and Geothermal Research >Measuring the size of non-spherical particles and the implications for grain size analysis in volcanology
【24h】

Measuring the size of non-spherical particles and the implications for grain size analysis in volcanology

机译：测量非球形颗粒的尺寸和火山学中晶粒尺寸分析的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

To quantify the size of tephra, two practical challenges must be addressed: the wide range of particle sizes (10(-8) 10(1) m) and the diversity of particle shape, density and optical properties. Here we use dynamic image analysis (DIA) to simultaneously characterise the size and shape of tephra samples from Mount Mazama, Krafla, Mount St. Helens and Campi Flegrei. The Camsizer X2 instrument used in this study, which has a measurement range of 0.8 mu m - 8 mm, avoids the need to overlap different measurement methods and principles for fine (125 mu m) and coarse (125 mu m) particle sizes. Importantly, DIA does not require an assumption of particle properties. DIA also allows the measurement of grain size distributions (GSDs) using multiple size definitions. Quantification by particle long axis and the area equivalent sphere diameter, for example, make DIA GSDs compatible with the outputs of other methods such as laser diffraction and sieving. Parallel mass-based (sieving) and volume-based (DIA) GSDs highlight the effects of particle density variations on methods of size analysis; concentrations of dense crystals within a narrow size range, in particular, can affect mass-based GSDs and their interpretations. We also show that particle shape has an important effect on the apparent grain size of distal tephra. Extreme particle shapes, such as the platy glass shards typical of the distal Campanian Ignimbrite deposits, can appear coarser than other distal tephras if size is quantified according to the particle long axis. These results have important implications for ash dispersion models, where input GSDs assume that reported measurements are for volume-equivalent sphere diameters. We conclude that DIA methods are not only suitable for characterising, simultaneously, the size and shape of ash particles but also provide new insights into particle properties that are useful for both ash dispersion modelling and studies of explosive volcanism. (C) 2021 The Author(s). Published by Elsevier B.V.
机译：为了量化Tephra的大小，必须解决两种实际挑战：粒度宽范围（10（-8）10（1）米）和颗粒形状，密度和光学性质的多样性。在这里，我们使用动态图像分析（Dia）同时表征来自Mast Mount Mount Mount Mount Mount Mount Mount Mount Mount Mount Mount St. Helens和Campi Flegrei的Tephra样本的尺寸和形状。本研究中使用的凸轮器X2仪器，其测量范围为0.8μm-8mm，避免了重叠不同的测量方法和原理的细（＆ 125 mu m）和粗（＆ 125 mu m）。粒子尺寸。重要的是，DIA不需要假设颗粒性质。 DIA还允许使用多个尺寸定义测量晶粒尺寸分布（GSD）。例如，通过粒子长轴和面积等效球直径进行量化，使得与其他方法的输出兼容，使得DIA GSD兼容，例如激光衍射和筛分。并行质谱（筛分）和基于体积的（直径）GSD突出了粒子密度变化对尺寸分析方法的影响;特别是窄尺寸范围内的致密晶体的浓度可以影响基于质量的GSD及其解释。我们还表明，颗粒形状对远端Tephra的表观粒度尺寸具有重要作用。极端粒子形状，例如典型的坎帕尼亚耳石沉积物的典型板碎片，如果尺寸根据粒子长轴定量尺寸，则可以显得比其他远端Tephras更粗糙。这些结果对灰分分散模型具有重要意义，其中输入GSDS假设报告的测量值用于体积等效的球体直径。我们的结论是DIA方法不仅适用于表征，同时，大小和灰颗粒的形状，而且提供新的见解是两种灰扩散模型和爆炸性火山的研究有用的粒子特性。 （c）2021提交人。由elsevier b.v出版。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号