Ash production by attrition in volcanic conduits and plumes
Ash production by attrition in volcanic conduits and plumes
复制标题
火山管道和羽流中的磨损产生的灰烬
作者：
T. Jones;J. Russell
火山灰沉积物由爆炸性火山喷发产生，可作为地下火山管道中破碎过程的间接探针。在管道上升过程中，原生岩浆碎裂通过挥发物驱动的减压产生了火山碎屑群。在这项研究中，我们探讨了二次破碎，特别是磨损，在火山管道和羽流中运输时原生火山碎屑转化中的作用。我们利用一组天然和实验生产的火山灰的总粒度分布来表明，在所有爆炸性火山喷发中都可能发生磨损。我们的实验结果表明，细灰的产生和表面积的生成速度很快（<15 分钟），从而迅速提高了火山灰沉积物的分形维数。此外，引入了一种新的指标，即信息熵，以量化粒度数据的磨损程度（二次碎片）。磨损增加了细火山灰的产生，进而对喷发柱的稳定性、火山灰的扩散、聚集、火山闪电的产生产生影响，并对航空安全和地球气候产生伴随影响。
Tephra deposits result from explosive volcanic eruption and serve as indirect probes into fragmentation processes operating in subsurface volcanic conduits. Primary magmatic fragmentation creates a population of pyroclasts through volatile-driven decompression during conduit ascent. In this study, we explore the role that secondary fragmentation, specifically attrition, has in transforming primary pyroclasts upon transport in volcanic conduits and plumes. We utilize total grain size distributions from a suite of natural and experimentally produced tephra to show that attrition is likely to occur in all explosive volcanic eruptions. Our experimental results indicate that fine ash production and surface area generation is fast (<15 min) thereby rapidly raising the fractal dimension of tephra deposits. Furthermore, a new metric, the Entropy of Information, is introduced to quantify the degree of attrition (secondary fragmentation) from grain size data. Attrition elevates fine ash production which, in turn, has consequences for eruption column stability, tephra dispersal, aggregation, volcanic lightening generation, and has concomitant effects on aviation safety and Earth’s climate.
影响因子：
5.8
作者：
Manzella, Irene;Bonadonna, Costanza;Monnard, Helene
通讯作者：
Monnard, Helene