CAREER: Long-term Controls on Short-term Patterns of Magmatism: Towards a Unified Framework for Crustal Magma Transport

确定岩浆在源区和地球表面之间迁移的路径和时间仍然是了解火山爆发及其危害的最大挑战之一。预测火山活动必须考虑隐藏在地表之下的岩浆运输过程，并反映出远远超出直接观测记录的岩浆和构造事件的综合历史。地质记录中与最大的火山爆发有关的任何形式的岩浆活动从未被直接观察到，这使得了解今天活跃的火山如何适应可能的火山过程的努力变得复杂。这一建议将在预测活火山过程和解释过去喷发记录的尺度上对岩浆运输产生新的认识。与此提案相关的更广泛的影响将利用火山数据的多样性来开发用于教学、推广和艺术桥梁的声音和可视化软件工具。本科教学和研讨会将制作地球科学教育材料。一系列的外联演示将使用声波和可视化技术将项目研究带给公众，包括与音乐家合作制作声波火山数据的录音和表演。这项提议有两个主要的科学目标。第一个目标是了解岩浆活动在最大尺度上的时空进展，重点关注标志性的哥伦比亚河洪水玄武岩。新的野外数据描述了美国俄勒冈州东部一个巨大的暴露的给料堤系统，将与热年代学和相关技术相结合，以限制地下岩浆流动的时间尺度。数值模型将阐明控制洪水玄武岩喷发的速度、体积和地壳运输结构的物理过程，使用贝叶斯反演方法在各种间接观测约束下正式评估模型的不确定性。这项工作应该为将洪水玄武岩喷发与包括气候和生物大灭绝在内的环境影响联系起来提供预测基础。第二个目标是建立一个地壳岩浆运输的建模框架，该框架通过水库和管道网络捕获多相流体运动和地表喷发周期，并与一个地壳模型相结合，该模型考虑了先前岩浆活动的热力学历史、远场强迫（即来自构造、气候）和地壳物质的非线性流变。该建模框架将用于探索控制喷发周期的物理和化学过程中的现象学权衡，并探索历史依赖的地应力和长期岩浆中心热演化的复杂性。对历史火山数据集以及哥伦比亚河洪水玄武岩的应用将为模型提供观测测试，而与其他人进行的完全相位分辨模拟的比较和校准将有助于弥合建模多尺度岩浆输送的不同方法。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。

Determining the pathways and timing of magma migration between the source region and Earth's surface remains one of the biggest challenges for understanding volcanic eruptions and their hazards. Predicting volcanic activity must contend with magma transport processes that are hidden beneath the surface and that reflect an integrated history of magmatic and tectonic events spanning far beyond direct observational records. Magmatism of any kind associated with the largest volcanic eruptions in the geologic record has never been directly observed, which complicates efforts to understand how volcanoes active today fit into the spectrum of possible volcanic processes. This proposal will generate new understandings of magma transport on scales that are relevant both to predicting active volcanic processes and to interpreting the record of past eruptions. Broader impacts associated with this proposal will leverage the great diversity of volcanic data to develop sonification and visualization software tools for use in teaching, outreach, and as a bridge to the arts. Undergraduate teaching and workshops will generate geoscience education materials. A series of outreach presentations will use sonification and visualization techniques to bring project research to the public, including a collaboration with musicians to produce recordings and performances of sonified volcanic data. There are two primary scientific objectives of this proposal. The first objective is to understand the spatiotemporal progression of magmatism at its largest scales, focusing on the iconic Columbia River Flood Basalts. New field data describing a massive exposed feeder dike system in eastern Oregon, USA, will be combined with thermochronology and related techniques that constrain timescales of subsurface magma flow. Numerical models will elucidate physical processes controlling the tempo, volumes, and crustal transport architecture feeding flood basalt eruptions, using Bayesian inversion methods to formally assess model uncertainty amongst diverse but indirect observational constraints. This work should provide a predictive basis for connecting flood basalt eruptions to environmental impacts including climate and mass extinctions of life. The second objective is to develop a modeling framework for crustal magma transport that captures multiphase fluid movement and surface eruption cycles through a network of reservoirs and conduits, coupled to a crustal model that accounts for the thermomechanical history of prior magmatism, far-field forcing (i.e. from tectonics, climate), and nonlinear rheology of crustal materials. This modeling framework will be used to explore the phenomenological trade-offs in physical and chemical processes that govern eruption cycles, and explore the complexities of history-dependent crustal stress and thermal evolution at long-lived magmatic centers. Applications to historical volcanic datasets as well as the Columbia River Flood Basalts will provide an observational test for models, while comparison to and calibration with fully phase-resolved simulations performed by others will help bridge divergent approaches to modeling multi-scale magma transport.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.