A new perspective on volcanic particle sedimentation and aggregation
A new perspective on volcanic particle sedimentation and aggregation
复制标题
火山颗粒沉积和聚集的新视角
DOI：
--
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
E. Rossi
中科院分区：
文献类型：
--
作者：
E. Rossi
最近的2010年埃亚菲亚德拉冰盖火山爆发（冰岛）的火山危机表明，即使是小规模的中度爆炸性火山爆发也会对我们的社会产生广泛影响。事实上，火山灰的长期预测仍然受到我们对颗粒选择性沉积过程（如颗粒聚集）的认识不足的影响。本论文的主要目标包括：i）基于现场、理论和实验的约束条件，建立一个可靠的数学框架来从理论上描述灰聚集。这种新的理论框架，命名为广义固定枢轴技术（GFPT），可以应用于不同的背景和学科; ii）更好地表征灰聚集的物理特性，提供了一个连贯的形式化。这导致了一个新的参数化的关键物理过程，如碰撞率和碰撞过程的粘附效率;和三）改善大型碎屑沉积的描述，以更好地描述火山爆发的羽流高度。
The recent volcanic crisis of 2010 Eyjafjallajokull eruption (Iceland) has demonstrated the widespread impact that even small-moderate explosive volcanic eruptions can have on our society. As a matter of fact the long range prediction of volcanic ash is still affected by our poor understanding of size-selective sedimentation processes, e.g. particle aggregation. Main objectives of this thesis include to: i) develop a robust mathematical framework to theoretically describe ash aggregation, based on field, theoretical and experimental constraints. This new theoretical framework, named the Generalized Fixed Pivot Technique (GFPT), can be applied in different contexts and disciplines; ii) better characterize the physics of ash aggregation, providing a coherent formalization. This resulted in a new parameterization of crucial physical processes, such as the collision rate and the sticking efficiency of collisional processes; and iii) improve the description of large clasts sedimentation in order to better characterize the plume height of volcanic eruptions.