RUI: Dynamics of Plinian Eruptions - Physical Volcanology of the 1600 Eruption of Volcan Huaynaputina, Southern Peru

[0087181]为了更好地了解火山爆发对人类、社会和环境的影响，科学家们越来越意识到，这一努力的根本基础是火山喷发的物理火山学知识。由于普林尼火山喷发是最具破坏性的火山之一，因此人们对这些现象进行了大量的研究。然而，很少有这样的喷发被观察和记录下来，我们的理解在很大程度上依赖于最近发生的喷发的数据。这些研究已被证明是我们了解普林尼火山喷发动力学及其局部和全球影响的主要来源。一项由美国国家科学基金会资助的对1600年埃纳普蒂纳火山喷发的完整研究表明，这次喷发是历史上最重大的喷发之一。喷发了超过25km3的火山灰，其中90%是在喷发第一阶段持续约20小时的普林尼火山喷发中喷出的。形成了两个同时期但不同的矿床；一个区域范围广泛且保存完好的滨浅浮石落矿床，以及一个范围更广的滨浅灰岩矿床。尽管大量喷发，但没有发生火山口崩塌，这使得罕见的保存了超近端部分和喷口。该项目将建立在喷发的一般模型上，我们已经阐明了将重点放在超近端部分和近端浮石落沉积上，以增加我们对1600年第一阶段普林尼火山喷发的理解，特别是普林尼火山喷发的动力学。要解决两个相互关联的目标。一是较好地约束了约20小时的普林尼期喷发演化；二是较好地认识了超近段极粗落层的成因及其意义。这些目标将通过广泛的实地工作来实现，包括对剖面进行测井，确定和绘制关键层位，并绘制其分布图。这些数据将与整个秋季沉积物中现有的详细粒度和层位成分相结合，以更详细地了解将约20小时的喷发分为几个阶段的第一阶段普林尼期喷发。研究生和本科生作为团队的主要参与者，最大限度地提高了这个项目的教育影响。

0087181DeSilvaIn attempting to better understand the human, societal, and environmental impacts of volcanic eruptions, scientists are increasingly aware that the fundamental underpinning to this endeavour is knowledge about the physical volcanology of volcanic eruptions. Since plinian eruptions are amongst the most devastating, considerable effort is focused on these phenomena. However, few such eruptions have been observed and documented and our understanding relies heavily on data from eruptions that have occurred in the recent past. Such studies have proved to be the source of much of our insight into the dynamics of plinian eruptions and their local and global effects. A completed study of the 1600 eruption of Huaynaputina, conducted under the auspices of a previous NSF grant, reveals that this eruption is one of the most significant eruptions of historic times. Over 25km3 of tephra was erupted, 90% of which was ejected during a ~20 hour sustained plinian eruption during the first stage of the eruption. Two coeval but distinct deposits formed; a regionally extensive and well-preserved plinian pumice fall deposit, and a much more extensive plinian ash deposit. No caldera collapse occurred despite the large volume erupted allowing the rare preservation of ultraproximal sections and vents. This project will build on the general model of the eruption that we have elucidated to focus on the ultraproximal sections and the proximal pumice fall deposit to increase our understanding of the 1600 Stage I plinian eruption in particular and the dynamics of plinian eruptions in general. Two interrelated objectives are to be addressed. The first is better constrain the evolution of the ~20 hour long plinian eruption, and the second is to better understand the origin and significance of the extremely coarse fall deposits in the ultraproximal sections. These objectives will be addressed through extensive fieldwork to log sections, identify and map key horizons, and map their dispersal. These data will be coupled with existing detailed grainsize and componentry of these horizons throughout the fall deposit to develop a more detailed understanding of the Stage I plinian eruption that breaks down the ~20 hour eruption into several stages. The involvement of graduate and undergraduate students as key players in the team maximises the educational impact of this project.