RUI: Collaborative Research: Testing the controls on eruption size and style at intermediate arc volcanoes: Evidence from the Holocene record at Augustine Volcano, USA

RUI：合作研究：测试对中弧火山喷发规模和类型的控制：来自美国奥古斯丁火山全新世记录的证据

• 批准号: 1948259
• 负责人: Alison Koleszar
• 金额: $ 12.52万
• 依托单位: Colgate University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1948259&HistoricalAwards=false
• 关键词: RUI; Collaborative; Research; Testing; controls

This project is jointly funded by the Petrology and Geochemistry and the Established Program to Stimulate Competitive Research (EPSCoR) programs. Augustine Volcano in Alaska is one of the most frequently active volcanoes in the US and is considered a very high threat by the U.S. Geological Survey. The hazards posed by a volcano depend on the size and style of an eruption, and many questions remain as to what controls these eruption characteristics at intermediate arc volcanoes like Augustine. For example, are large and explosive eruptions driven by larger volumes of magma supply at shallow depths in the crust, or by faster ascent rates, or both? Prehistoric tephras (named Tephra B and Tephra M) that erupted from Augustine Volcano can provide insight into how eruptive behavior changes through time. This project has as a goal to investigate the links between magma plumbing systems and eruption explosivity. It will target two of the primary factors that determine eruption style: magma composition and the rate at which the magma ascends through the crust. Important societal benefits will emerge from this work, specifically related to volcanic hazards in the US, and that are broadly applicable to other intermediate arc volcanoes globally. Finally, this project initiates new volcano observatory-academic partnerships between the Alaska Volcano Observatory, Colgate University, and Middlebury College. This partnership will accelerate the translation of basic science to applications and monitoring that will provide active research-based curricula at two undergraduate institutions. The goals of this project are to: 1) use whole rock (pumice), phenocryst, glass, and melt inclusion geochemical data to identify the number, geometry, and relationships between the subsurface magmatic reservoirs that fed the eruptions that produced units Tephra M and Tephra B at Augustine, 2) investigate indicators of magmatic ascent rate such as volatile concentrations, crystal textures, and bubble textures within the erupted material, 3) characterize how volcanic plumbing systems evolve through time by comparing tephras B and M to historic and older prehistoric and Pleistocene deposits, and 4) investigate small-scale variability in eruption style through detailed sampling within the stratigraphy of Tephras M and B, with a targeted effort to characterize both microlite-poor and microlite-rich samples. This will resolve some of the observational bias that exists in Augustine’s record, and will help characterize the potential magnitude and importance of this bias at intermediate arc volcanoes. Data from this project will provide new constraints on the physical and chemical processes that drive ascent and explosivity and determine how magma storage reservoirs evolve over time.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.

该项目由岩石与地球化学和促进竞争研究（EPSCoR）计划共同资助。阿拉斯加的奥古斯丁火山是美国最活跃的火山之一，被美国地质调查局认为是一个非常高的威胁。火山造成的危害取决于喷发的规模和方式，像奥古斯丁这样的中间弧型火山的喷发特征是由什么控制的，这些问题仍然存在。例如，大规模的爆炸性喷发是由地壳深处大量岩浆供应驱动的，还是由更快的上升速度驱动的，还是两者兼而有之？从奥古斯丁火山喷发出来的史前火山（名为Tephra B和Tephra M）可以让我们深入了解火山喷发行为是如何随着时间的推移而变化的。这个项目的目标是研究岩浆管道系统和火山喷发爆炸性之间的联系。它将针对决定喷发方式的两个主要因素：岩浆成分和岩浆穿过地壳上升的速度。这项工作将产生重要的社会效益，特别是与美国的火山危害有关，并广泛适用于全球其他中弧火山。最后，这个项目启动了新的火山观测站——阿拉斯加火山观测站、科尔盖特大学和米德尔伯里学院之间的学术合作伙伴关系。这一伙伴关系将加速将基础科学转化为应用和监测，从而在两所本科院校提供积极的研究型课程。这个项目的目标是：1)利用整块岩石（浮石）、斑晶、玻璃和熔体包裹体地球化学数据来确定地下岩浆储层的数量、几何形状以及它们之间的关系，这些地下岩浆储层为奥古斯丁火山喷发提供了岩浆，形成了Tephra M和Tephra B单元；2)研究岩浆上升速率的指标，如喷发物质中的挥发性浓度、晶体结构和气泡结构；3)通过将tephras B和M与历史上的、更古老的史前和更新世沉积物进行比较，表征火山管道系统是如何随时间演变的；4)通过在tephras M和B的地层中进行详细采样，研究喷发风格的小规模变化，并有针对性地表征微岩缺乏和微岩丰富的样品。这将解决奥古斯丁记录中存在的一些观测偏差，并将有助于描述这种偏差在中弧火山的潜在规模和重要性。该项目的数据将为驱动上升和爆炸性的物理和化学过程提供新的约束条件，并确定岩浆储层如何随时间演变。该奖项反映了美国国家科学基金会的法定使命，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。