Collaborative Research: Investigating the role of topography and magma properties on dike pathways beneath stratovolcanoes using field data, analogue experiments, and modeling

火山爆发是美国的一个主要自然灾害，美国大约有169座潜在的活火山，其中许多位于人口迅速增长的地区。虽然监测火山动荡无疑对火山爆发预测很重要，但对监测数据的准确解释和对未来火山行为的预测需要对将岩浆从地壳储存区输送到地表的过程有科学的了解。该项目将提高人们对是什么导致岩浆在雷尼尔山和胡德山等大型成层火山下的地下向不同方向移动的认识。这项工作将测试岩浆的物理性质和火山建筑物的大小如何影响喷发位置，目前对此知之甚少。该项目支持对研究生和本科生进行跨学科培训，以及编制将在大学课堂上实施并提供给公众用于广泛课堂和在线教育用途的教育材料。该项目的主要目标是确定是什么控制着成层火山下岩浆岩脉的路径。成层火山下地壳的应力扰动被认为会影响上升岩脉的传播方向，可能会阻止传播或使岩脉向侧翼偏转，并导致低海拔地区的喷发，这可能对当地社区造成危害。拟议的三年期项目将采用一种协同方法，将地质场数据、模拟明胶实验和数值模型相结合，以研究成层火山载荷产生的应力场和岩浆性质的变化如何影响从地壳源上升的岩脉的几何形状和传播。拟议的工作包括地质测绘和样品收集暴露在夏季库恩，侵蚀成层火山在科罗拉多，测量岩脉露头的几何形状，流动织物，物理岩浆性质，如密度和泡状。使用一种新的实验装置和输入参数的限制，现场数据，明胶实验将包括注入岩浆类似物下的模拟edibrium调查可变edibrium的高度/坡度，岩浆密度和堤坝注入深度对堤坝传播的影响。最后，现场和实验结果将通知新的数值模型，旨在评估火山建筑物下的地壳应力，并研究面内岩脉传播方向如何作为建筑物几何形状，岩浆浮力，初始岩浆压力，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进行评估，被认为值得支持审查标准。

Volcanic eruptions are a major natural hazard in the United States, where there are about 169 potentially active volcanoes, many of which are located in areas with rapidly expanding populations. Although monitoring volcanic unrest is undoubtedly important to eruption forecasting, accurate interpretation of monitoring data and prediction of future volcano behavior require a scientific understanding of the processes that transport magma out of storage regions in the Earth’s crust and towards the surface. This project will enhance knowledge about what causes magma to move in different directions through the subsurface under large stratovolcanoes such as Mount Rainier and Mount Hood. The work will test how the physical properties of magma and the size of the volcanic edifice influence eruption location, which is currently poorly understood. The project supports interdisciplinary training of graduate and undergraduate students, as well as the development of educational materials that will be implemented in university classrooms and made available to the public for broad classroom and online educational use.The primary objective of this project is to determine what controls the pathways of magmatic dikes under stratovolcanoes. Stress perturbations in the crust beneath a stratovolcano are thought to impact the propagation direction of ascending dikes, potentially arresting propagation or deflecting dikes toward the flanks and causing eruptions at lower elevations that can be hazardous to local communities. The proposed three-year project will employ a synergistic approach that integrates geologic field data, analogue gelatin experiments, and numerical models to investigate how the stress field generated by the load of stratovolcanoes and variations in magma properties impact the geometry and propagation of dikes ascending from crustal sources. The proposed work includes geologic mapping and sample collection from the radial dike sequence exposed at Summer Coon, an eroded stratovolcano in Colorado, to measure dike outcrop geometries, flow fabrics, and physical magma properties like density and vesicularity. Using a novel experimental setup and input parameters constrained by field data, gelatin experiments will include injecting magma analogues beneath a simulated edifice to investigate the impacts of variable edifice height/slopes, magma densities, and dike injection depths on dike propagation. Finally, field and experimental results will inform new numerical models designed to evaluate crustal stresses beneath a volcanic edifice and investigate how in-plane dike propagation directions vary as a function of edifice geometry, magma buoyancy, initial magma pressures, and dike injection depths.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.