Collaborative Research: BENEATH THE FOUNTAINS: Shallow conduit processes and diversity in basaltic fissure eruptions.

温和的喷发--地球上最常见的空中喷发火山--大致分为两种类型：斯特龙博尔式和夏威夷式。前者以间歇性离散爆炸为特征，后者以持续的火山碎屑喷泉作用为特征。2018年Kī劳厄火山(夏威夷ʻI)裂缝喷发期间的爆炸活动提供了一个记录斯特龙博尔和夏威夷广泛行为的特殊机会(图1)，这要归功于火山的可访问性和在整个事件中收集的丰富的数据类型。这项研究探讨了火山下方管道系统中的哪些过程，与KīLauea和其他地方之前更一致的裂缝喷发相比，2018年爆炸活动在风格和强度上的巨大差异？KīLauea是一座异常活跃的火山，它的喷发给管理机构带来了持续不断的挑战，因为喷发地点很容易进入，需要平衡公众对观看喷发活动的强烈兴趣和公共安全(如2018年所见)。这种平衡需要对火山当前和未来行为的复杂知识的严格要求。公众既希望更好地了解火山的行为，也需要改进对未来所有喷发的可能路线和足迹的预测。天文台的合作伙伴，美国地质勘探局，具有联邦授权的作用，为夏威夷的反应机构提供建议，并将把知识从NSF资助的研究转移到负责风险管理的机构。这项工作涉及美国和英国机构之间的材料和思想交流，使年轻的研究人员和学生受益。结果将通过会议和讲习班、联邦应急管理局资助的国家备灾培训中心提供的课程、互联网和科学出版物以及计划的基拉韦虚拟实地旅行广泛传播。这项研究的目标是将现有对玄武岩裂缝爆炸性喷发的高分辨率观测与极浅管道中引起和塑造它们的过程联系起来，重点是2018年Kī劳厄火山喷发作为案例研究。它将结合来自高时间和空间分辨率视频的现有数据：(1)五个具有代表性的火山碎屑足迹的现场测量，以及喷射物的实验室表征，(2)两相岩浆流变学的高精度测量，以及(3)与新完成的实验室模拟实验相关联的模型，以模拟出气模式。这种方法预计将有助于确定伴随着喷发式过渡的模式和前兆，支持这座非常活跃的火山侧翼社区的风险管理。这项研究将从根本上提高我们对夏威夷和斯特龙博利亚火山喷发动力学的理解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Mildly explosive eruptions—the most frequent manifestations of subaerial explosive volcanism on Earth—broadly group into two styles: Strombolian and Hawaiian. The former is characterized by sequences of intermittent discrete explosions and the latter by sustained pyroclastic fountaining. Explosive activity during the 2018 fissure eruption of Kīlauea volcano (Hawaiʻi) provided an exceptional opportunity to record a wide range of Strombolian and Hawaiian behavior (Figure 1), thanks to the accessibility of the volcano and the wealth of data types collected throughout the event. This study address which processes in the plumbing system beneath the volcano ‘drove’ the great diversity in style and intensity of the 2018 explosive activity compared to previous, more consistent, fissure eruptions at Kīlauea and elsewhere? Kīlauea is an exceptionally active volcano and its eruptions pose constant challenges for management agencies because the eruption sites are highly accessible and there is a need to balance the strong popular interest in viewing the eruptive activity against public safety (as seen in 2018). This balance requires critically on sophisticated knowledge of the volcano’s current and immediately future behavior. There is both a public desire for better knowledge of the volcano’s behavior and a need for improved forecasting of the likely course and footprint of all future eruptions. The observatory partner, USGS, has a federally mandated role to advise response agencies in Hawaii and will transfer knowledge from the NSF-funded study to the bodies charged with risk management. This work involves exchange of material and ideas between institutions in the USA, and the United Kingdom to the benefit of young researchers and students. The results will be widely disseminated via meetings and workshops, courses offered by the FEMA-funded National Disaster Preparedness Training Center, the Internet and scientific publications and a planned virtual field trip to Kilauea.The goal of this study is to link existing high-resolution observations of explosive basaltic fissure eruptions to the processes in the very shallow conduit that cause and shape them, focusing on the 2018 Kīlauea eruption as a case study. It will combine existing data derived from high temporal and spatial resolution videos with: (1) field measurements of five representative pyroclastic footprints, and laboratory characterization of the ejecta, (2) high-precision measurements of two-phase magma rheology, and (3) models tied to newly completed laboratory analog experiments to simulate outgassing patterns. This approach is expected to help identify patterns and precursors that accompany transitions in eruptive style, supporting risk management for communities on the flank of this very active volcano. This study will fundamentally improve our understanding of the dynamics of Hawaiian and Strombolian eruptions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.