Collaborative Research: Phenocryst or not? Using a stratovolcano's crystal cargo to explore crustal-scale magmatic systems, Koma Kulshan (Mt. Baker), Northern Cascade Arc

该提案的目标是通过对华盛顿州北部科马库尔山（贝克山）喷发的熔岩进行地球化学和矿物学研究，解决火山科学中与火山如何以及何时喷发有关的基本问题。美国有几个火山活跃地区，包括科马库尔山在内的“非常高威胁”火山。虽然位于人口稠密的地区，但对科马库尔山的研究相对较少。本提案调查了导致科马库尔山火山喷发的过程和相关的时间尺度，以便在未来爆发时更好地为应对和帮助制定减灾计划提供信息。这项工作还将通过夏季Koma Kulshan实地体验为来自STEM领域边缘群体的学生提供基于地点的学习机会，这是一个为期一周的夏季实地体验，面向来自华盛顿州立机构的预科学生，包括西北印第安学院、Whatcom社区学院和亚基马山谷学院。此外，三名具有互补的科学专业知识和不同职业阶段的不同身份的pi将领导这个合作项目，并将为华盛顿州的本科生和研究生提供多层次研究指导框架。这一建议概述了过去~100 ka从科马库尔山喷发的熔岩和火山沉积物的研究。它提供了一种综合方法，将成熟的岩石学技术（即矿物化学、结构和热气压测定法）与突破性的方法（即机器学习、扩散计时法和熔融包裹体中的重建挥发物）相结合。得到的数据将用于重建弧壳中岩浆储存的结构，并量化岩浆储存和喷发前上升的时间——这是卡斯卡迪斯火山观测站实施喷发事件树和减灾计划所需的关键因素。库尔山熔岩为这项研究提供了一个独特的理想样本集，因为之前的工作已经确定了不同的晶体凝块和共结晶组合，它们代表了在数万年的火山喷发中形成的跨地壳系统的不同部分。这项工作提供了测试跨地壳岩浆系统如何随时间演变的机会，并提高了我们对全球弧火山的理解。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。

The goal of this proposal is to address fundamental questions in volcano science related to how and when volcanoes erupt through a geochemical and mineralogical study of lavas erupted from Koma Kulshan (Mt. Baker) in northern Washington State. The United States has several volcanically active regions that contain “very-high-threat” volcanoes, including Koma Kulshan. While situated in a highly populated area, Koma Kulshan remains relatively understudied. This proposal investigates the processes that lead to eruptions at Koma Kulshan and the associated timescales, to better inform a response to, and aid in, hazard mitigation plans in the event of a future eruption. This work will also provide place-based learning opportunities for students from marginalized groups in STEM through the Summer Koma Kulshan Field Experience, a week-long summer field experience for pre-majors from Washington State institutions including Northwest Indian College, Whatcom Community College, and Yakima Valley College. Additionally, three PIs with complementary scientific expertise and diverse identities at different career stages will lead this collaborative project and will provide a framework for multi-tiered research mentoring across peer institutions in the state of Washington for undergraduates and graduate students.This proposal outlines an investigation of lavas and tephra deposits erupted from Koma Kulshan over the past ~100 ka. It provides an integrated approach combining proven petrologic techniques (i.e., mineral chemistry and textures and thermobarometry) with methodologies that are breaking new ground (i.e., machine learning, diffusion chronometry, and reconstructed volatiles in melt inclusions). The resultant data will be used to reconstruct the architecture of magma storage in arc crust and quantify the timing of magma storage and ascent prior to eruption–key factors required for eruption event trees and hazard mitigation plans implemented by the Cascades Volcano Observatory. Kulshan lavas provide a unique sample set ideal for this study as previous work has identified distinct crystal clots and co-crystallizing assemblages that represent different parts of a transcrustal system tapped upon eruption over 10s of thousands of years. This work provides the opportunity to test how transcrustal magmatic systems evolve through time and improves our understanding of arc volcanoes globally.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.