Volatile budget of Yellowstone magmas: investigating eruptive triggers and environmental effects of the largest explosive eruptions on earth

托马斯博士R.本森被授予博士后研究金，在纽约的美国自然历史博物馆进行研究和教育推广。调查将通过分析黄石高原火山区（美国蒙大拿州怀俄明州和爱达荷州）最近三次大规模火山爆发，评估大型超级火山爆发的触发机制和环境影响。PI将收集现场样品并对其进行实验室工作，以确定火山爆发前岩浆中存在的挥发性化学物质（H2O、S、F、Cl）的丰度，并量化火山爆发期间损失到大气中的数量。这项工作将为地方和区域社区的超级火山危险评估提供信息。由此产生的模型将有助于更好地了解未来火山爆发对全球环境的影响。此外，将创建黄石国家公园火山特征的360度虚拟现实视频，以使公园更容易向公众开放，并利用AMNH的外展计划吸引当地高中和本科生参与科学研究。这项调查将是第一次全面研究黄石岩浆中的挥发性系统学，特别是那些导致火山口形成的喷发。这项工作将涉及使用西姆斯分析磷灰石斑晶、微斑晶和其他矿物中的包裹体，以评估平衡岩浆挥发物浓度。石英和辉石斑晶内均质熔体包裹体的西姆斯，电子探针和FTIR分析也将被用来限制岩浆的挥发性成分。所有分析相的相对结晶或捕获顺序将使用热力学约束和岩相关系来确定，以评估挥发性组分的浓度如何随时间在岩浆中变化。浓度将与使用西姆斯、电子探针和FTIR在脱气基质玻璃中测量的值进行比较，以量化在这些喷发过程中可能损失到大气中的挥发物的量。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。

Dr. Thomas R. Benson has been awarded an EAR postdoctoral fellowship to conduct research and educational outreach at the American Museum of Natural History in New York. The investigation will assess triggering mechanism(s) and environmental effects of large supervolcanic eruptions through analysis of the most recent three major eruptions at the Yellowstone Plateau Volcanic Field (Wyoming, Montana, and Idaho, United States). The PI will collect field samples and perform laboratory work on them to determine the abundances of volatile chemicals (H2O, S, F, Cl) present in the magmas before the eruptions and quantify the amounts lost to the atmosphere during the eruptions. This work will inform hazard assessments of supervolcanoes to local and regional communities. The resulting models will improve understanding on the effects of future eruptions to the global environment. In addition, 360 degree virtual reality videos of volcanic features at Yellowstone National Park will be created to make the park more accessible to the public and utilize outreach programs at AMNH to engage local high school and undergraduate students in scientific research. This investigation will be the first comprehensive study of volatile systematics in Yellowstone magmas, in particular those that lead to caldera-forming eruptions. The work will involve analysis of apatite phenocrysts, microphenocrysts, and inclusions within other minerals using SIMS to evaluate equilibrium magma volatile concentrations. SIMS, electron microprobe, and FTIR analyses of homogenized melt inclusions within quartz and pyroxene phenocrysts will also be used to constrain the volatile composition of the magmas. Relative crystallization or entrapment order of all analyzed phases will be determined using thermodynamic constraints and petrographic relationships to assess how the concentrations of volatile components changed in the magmas with time. Concentrations will be compared to values measured in degassed matrix glasses using SIMS, electron microprobe, and FTIR to quantify the amount of volatiles that may have been lost to the atmosphere during these 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.