CAREER: Rethinking the Dynamics of Magma Storage and Eruption for Yellowstone’s Youngest Supereruption’

在黄石国家公园下面有一个活跃的热源，它为每年吸引400多万游客的热气腾腾的泉水和喷涌的间歇泉提供燃料。在过去，这种热源导致了大规模的火山爆发，创造了我们今天看到的散布在景观中的许多岩石。由于黄石公园是一个受联邦政府保护的活火山中心，科学家有义务了解地质历史和如此巨大的火山系统可能造成的危害，并将这些信息传达给每年访问的社区和人们。该项目旨在系统地调查最年轻的超级喷发，熔岩溪凝灰岩，它产生了现代黄石火山口。要解决的问题包括：（1）岩浆是如何定位在地表之下的？(2)是什么触发了岩浆向地表移动(3)岩浆是从哪里喷发的？以及（4）所有这些过程发生需要多长时间（天、周、年）？在整个项目中，研究人员将培训下一代地质学家，以发展他们作为科学家和传播者的技能。黄石公园提供了一个理想的环境来教授与地质测绘，批判性思维和岩石分析相关的技能，这就是为什么这个提案的结构是为八名本科生和三名研究生提供夏季测绘经验，重点是招募来自代表性不足背景的学生。所有学生将接受培训，成为黄石科学的积极管理者，撰写博客文章，并准备向公众传达黄石火山的地质和监测的演示文稿。大量流纹岩岩浆聚集、储存在上地壳并被触发喷发的机制和时间尺度仍然是火山学中的基本问题。本提案的总体研究目标是重新评估黄石火山区（YVF）熔岩溪凝灰岩（LCT; 0.63 Ma）最年轻的超级喷发的组合、储存和喷发动力学。这项工作是由2018年发现的两个新的熔结凝灰岩单元引发的，这两个单元以前未被识别（并且目前在空间上不受限制）属于LCT。此外，LCT内沉积间化学变化的提示存在于已建立的文献中，但目前定义不清。该建议的工作假设是，LCT喷发由多个岩浆体组成，沿着破火山口边界沿着有差异地挖掘，与更好地研究的哈克贝利岭凝灰岩（Huckleberry Ridge Tuff）中推断的结果相当，这是YVF最古老的（2.08 Ma）超级喷发。通过结合详细的实地测绘、广泛的全岩、玻璃地球化学和岩相分析、扩散建模和年龄测定，该项目将重新思考黄石公园最年轻的超级喷发的构成和进展。本研究的教育目标是利用蒙大拿州立大学与地球上最大的火山系统之一的接近度（1.5小时），将其用作培训下一代地质学家的实地实验室。该项目提供了许多机会，实践科学传播鉴于超过400万游客参观公园每年。所有的学生都将接受培训，成为黄石科学的积极管理者，撰写博客文章，准备公开演讲，传达黄石火山的地质和监测工作。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Beneath Yellowstone National Park exists an active heat source which fuels the steaming springs and gushing geysers that draw more than 4 million visitors to the park every year. In the past, this heat source resulted in large-volume volcanic eruptions that created many of the rocks we see scattered across the landscape today. Because Yellowstone is a federally protected and active volcanic center, scientists have an obligation to understand the geologic history and possible hazards of such a massive volcanic system and to convey this information to the communities and people that visit each year. This project aims to systematically investigate the youngest supereruption, the Lava Creek Tuff, which produced the modern-day Yellowstone caldera. The questions to be addressed include: (1) how was magma positioned beneath the surface? (2) what may have triggered the magma to move to the surface? (3) where did magma erupt from? and (4) how long (days, weeks, years) did it take for all of these processes to occur? Throughout this project, the researchers will be training the next generation of geologists to develop their skills as scientists and communicators. Yellowstone provides an ideal setting to teach skills related to geologic mapping, critical thinking, and rock analysis, which is why this proposal is structured to provide eight undergraduate and three graduate students with summer mapping experiences, with an emphasis on recruiting students from underrepresented backgrounds. All students will be trained to be active stewards of Yellowstone science, writing blog articles and preparing presentations that communicate to the public the geology and monitoring of Yellowstone Volcano. The mechanisms and timescales by which large volumes of rhyolitic magma accumulate, are stored in the upper crust and are triggered to eruption remain fundamental questions in volcanology. The overall Research Objective of this proposal is to reevaluate the assemblage, storage and eruption dynamics of the youngest supereruption from the Yellowstone Volcanic Field (YVF), the Lava Creek Tuff (LCT; 0.63 Ma). This work was ignited by the 2018 discovery of two new ignimbrite units previously unrecognized (and currently spatially unconstrained) as belonging to the LCT. Additionally, hints of inter-depositional chemical variations within the LCT exist in the established literature but are currently poorly defined. The working hypothesis of this proposal is that the LCT eruption consisted of multiple magma bodies tapped differentially along the caldera boundary, comparable to what is inferred in the better-studied Huckleberry Ridge Tuff, the oldest (2.08 Ma) supereruption from the YVF. Through a combination of detailed field mapping, extensive whole rock, glass geochemistry and petrographic analysis, diffusion modeling and age dating, this project will rethink the makeup and progression of the youngest Yellowstone supereruption. The Educational Objective of this study is to leverage the proximity (1.5 hours) of Montana State University to one of the largest volcanic systems on Earth, using it as a field-based laboratory for training the next generation of geologists. This project presents numerous opportunities for practicing science communication in light of over 4 million tourists that visit the park each year. All students will be trained to be active stewards of Yellowstone science, writing blog articles and preparing public presentations that communicate the geology and monitoring efforts of Yellowstone Volcano.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.