EAR-PF The Role of Deformation in Triggering Volcanic Eruptions

Amy Ryan博士获得了美国国家科学基金会EAR博士后奖学金，在明尼苏达大学进行研究，以确定岩浆房的变形在引发火山爆发中的作用。像黄石火山（美国）这样的超级火山是由岩浆室滋养的，岩浆室里有小袋的岩浆，这些岩浆分布在一个不动的岩浆“糊状”体中，其间以岩浆填充的晶体为主。当物理力量引起地壳的变化时，火山爆发和相关的动荡就会发生，这些小口袋穿过糊状物到达地表。对喷发的熔岩的研究表明，从地质学角度来说，这种运动可能会突然发生，持续时间短至几个月，也可能长达数百年。然而，流体岩浆在坚硬的、不动的岩浆中移动的物理条件和过程是未知的。瑞安博士的工作包括重建超级火山下的条件的实验，以描述驱动火山下岩浆运动的地质过程。瑞安博士的研究结果将有助于深入了解导致火山动荡加剧的条件，并帮助那些监测活火山的人制定更好的风险缓解策略。这项工作包括在明尼苏达州北部的实地工作。Ryan博士将与Wolf Ridge学习中心合作，为K-12学生开发下一代科学标准（NGSS）课堂课程，以及一系列互动现场指南。此外，Ryan博士将在研究和教材开发的各个方面指导本科生。瑞安博士将在气体介质中进行高温高压变形实验，帕特森仪器。实验样品将由一个玻璃盘（“岩浆”）和一个复合材料盘（“糊状”）组成，该复合材料盘由破碎的玻璃和高达80%晶体分数的细石英砂混合而成。样品将被加热和加压，然后经受孔隙压力梯度，以代表天然储层中岩浆和岩浆变形条件的速率和幅度进行压缩或剪切。在变形之后，对样品的分析将包括专门的成像，以寻找岩浆渗透结构，并测量迁移岩浆的体积。该项目的主要目标是：(1)确定在高粘度、低渗透的泥状地层中形成膨胀区域的变形条件（类型、速率和大小），使岩浆能够渗入；(2)根据实验结果，确定可能引发岩浆渗入并最终导致储层重组的多尺度地质过程。这些结果可用于约束上地壳岩浆提取和运移数值模型的输入参数。该项目的研究成果将以高影响力、开放获取、同行评议的文章、会议报告、公开讲座、大学网站和社交媒体的形式传播。此外，该项目还将包括一项实地研究，将实验中形成的纹理与自然侵入体中形成的纹理进行比较，并保存在岩石记录中。实地工作将包括来自当地社区或部落学院的学生的参与。最后，将根据实验工作和实地研究编写教材，提供给当地学习中心和学校。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。

Dr. Amy Ryan has been awarded an NSF EAR Postdoctoral Fellowship to carry out research at the University of Minnesota to determine the role that deformation of magma chambers plays in setting off volcanic eruptions. Supervolcanoes like Yellowstone volcano (USA) are fed by magma chambers that have small pockets of fluid magma distributed within a body of immobile magma “mush, dominated by crystals with magma filling in spaces between. Volcanic eruptions and associated unrest occur when physical forces cause changes in the Earth’s crust and those pockets move through the mush to the surface. Studies of erupted lavas have shown that this movement can occur suddenly, geologically speaking, taking as little as a few months to hundreds of years. However, the physical conditions and processes that allow the fluid magma to move through the stiff, immobile mush are unknown. Dr Ryan’s work includes experiments that recreate conditions beneath supervolcanoes to characterize the geologic processes that drive magma movement beneath volcanoes. The results of Dr. Ryan’s study will provide insight into the conditions that lead to increased volcanic unrest and help those monitoring active volcanoes to create better risk mitigation strategies. The work includes field work in northern Minnesota. Dr. Ryan will partner with the Wolf Ridge Learning Center to develop Next Generation Science Standard (NGSS)-aligned classroom lessons for K-12 students, as well as a series of interactive field guides. Additionally, Dr. Ryan will mentor undergraduates in all aspects of research and the development of educational materials. Dr. Ryan will be conducting high-temperature and high-pressure deformation experiments in a gas-medium, Paterson apparatus. Experimental samples will consist of a disk of glass (“magma”) stacked in series with a disk of a composite (“mush”) composed of crushed glass mixed with fine quartz sand up to a crystal fraction of 80%. Samples will be heated and pressurized then be subjected to pore-pressure gradients, compressed or sheared at rates and magnitudes representative of deformation conditions mushes and magmas experience in natural reservoirs. Following deformation, analyses of samples will include specialized imaging to look for magma infiltration structures and to measure the volume of migrated magma. The major project objectives are to (1) determine the deformational conditions (type, rate and magnitude) that create dilatant regions in the high-viscosity, low-permeability mush that allow for magma infiltration and (2) based on experimental results, identify the multi-scale geologic processes that can feasibly trigger magma infiltration and, as a result, reservoir reorganization. These results will find application in constraining input parameters for numerical models of magma extraction and transport in the upper crust. Research outputs from this project will be disseminated in high-impact, open-access, peer-reviewed articles, conference presentations, public lectures, university-based websites and social media. In addition, the project will also include a field study to compare textures that form in experiments to those that developed in natural intrusive bodies and are preserved in the rock record. Field work will involve the participation of students from local community or tribal colleges. Finally, educational materials will be developed based on the experimental work and field study and be made available for local learning centers and schools.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.