The Fidelity of Glass Reentrants in Crystals: Witnesses of Decompression and Stalling of Magma in Conduits

由于超过5亿人（占世界人口的9%）生活在火山的最大暴露范围内，研究火山系统的一些最重要的问题涉及灾害监测和缓解。然而，确定个别火山构成的风险类型的能力在很大程度上取决于准确解释其喷发产物（如浮石和火山灰）的挑战性任务，这对历史上不活跃的系统尤其重要。该项目旨在提高使用喷发产物来解释大规模爆炸性喷发随时间演变的能力。为了实现这一目标，1991年火山爆发的产物。皮纳图博（菲律宾）将被研究，这是世纪观察到的最大的爆炸性喷发之一。通过量化的时间尺度相关联的离散阶段的喷发，控制这些暴力事件的演变过程将被重建。这些结果将被整合到从Mt.皮纳图博，创建一个前所未有的数据库，将现代火山喷发监测数据与通常用于解释历史矿床的实地方法联系起来。除了这些科学的影响，这将支持一个女人谁是一个新的NSF PI，并将支持几个研究生和本科生。该项目由岩石学地球化学和刺激竞争性研究的既定计划（EPSCoR）共同资助。皮纳图博经历了几天的离散，较小的次普利尼亚爆发，这加剧了6月15日的气候喷发。通过对南岳山减压历史的重建。皮纳图博喷发序列，并将此信息与地震记录相结合，可以提供一个显着的进步，将一个共同的监测技术与一个容易应用的岩相学工具。岩浆减压的定量记录，在不断升级的活动的日子里，将获得通过测量的浓度和梯度的挥发物（H2O，CO2，Cl，Li，F）保存在折返（开放的熔体口袋托管在晶体）和耦合这一信息与微晶生长时标。通过将这些方法与详细的取样相结合，将确定岩浆在爆炸活动中断期间停滞了多长时间和在哪里。进一步的信息将来自减压实验，这将允许通过模拟测试所有的上升率解释。该项目涉及与美国地质调查局的科学家，美国三所大学的合作，菲律宾的研究人员。最终，该项目提供的数据集将使我们能够询问是否可以看到证据，证明最终在喷发产物中保存的喷发能量升级。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

As more than 500 million people (9% of the world population) live within the maximum exposure range of a volcano, some of the most important questions for studying volcanic systems regard hazard monitoring and mitigation. However, much of the ability to define the type of risks posed by individual volcanoes relies on the challenging task of accurate interpretation of their eruptive products (e.g. pumice and ash), particularly crucial in systems that have not been historically active. This project aims to improve the ability to use eruptive products to interpret how large, explosive eruptions evolve over time. To accomplish this, the erupted products from the 1991 eruption of Mt. Pinatubo (Philippines) will be studied, one of the largest explosive eruptions observed in the 20th century. Through quantifying the timescales associated discrete phases of this eruption, the processes controlling the evolution of these violent events will be reconstructed. These results will be integrated into the dense seismic and visual records collected from Mt. Pinatubo, creating an unprecedented database for linking modern eruption monitoring data with a field-based approach typically used for interpreting historic deposits. In addition to these scientific impacts, this will support a woman who is a new NSF PI, and will support several graduate and undergraduate students. This project is jointly funded by Petrology & Geochemistry and the Established Program to Stimulate Competitive Research (EPSCoR).Mt. Pinatubo experienced several days of discrete, smaller sub-plinian explosions, which ramped up to the June 15th climatic eruption. Reconstructing the decompression history through the Mt. Pinatubo eruptive sequence, and pairing this information with the seismic record, could provide a remarkable advancement for linking a common monitoring technique with a readily applied petrographic tool. A quantitative record of magma decompression during the days of escalating activity will be obtained by measuring concentrations and gradients of volatiles (H2O, CO2, Cl, Li, F) preserved in reentrants (open melt pockets hosted in crystals) and coupling this information with microlite growth timescales. Through combining these methods with detailed sampling, an understanding for how long and where magma was stalled during breaks in explosive activity will be determined. Further information will come from decompression experiments, which will allow for testing all ascent-rate interpretations through simulations. This project involves collaborations with scientists at the United States Geological Survey, three universities within the U.S., and researchers in the Philippines. Ultimately, the dataset afforded by this project will allow us to ask whether one can see evidence for what ended up being an escalation in eruptive energy preserved within the erupted products.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.