Fluid oscillations in conduit-reservoir systems, very long period seismic signals at Kilauea volcano, and the phenomenology of unsteady magma ascent

管道-储层系统中的流体振荡、基拉韦厄火山的超长周期地震信号以及不稳定岩浆上升的现象学

• 批准号: 2036980
• 负责人: Leif Karlstrom
• 金额: $ 28.67万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2036980&HistoricalAwards=false
• 关键词: Fluid; oscillations; conduit; reservoir; systems

Volcanic eruptions and the human hazards associated with them are challenging to predict because they involve highly unsteady motions of magma hidden below Earth’s surface. Although observations critical for inferring subsurface magma motions, such as seismicity and infrasound, are being collected more and more often, we lack a theoretical framework for understanding the physical processes that give rise to such signals. This work will be a study of magma flow within volcanic conduits on short timescales, in order to understand the physical processes that give rise to a variety of eruptive phenomena. The first goal is to study volcanic activity at Kilauea volcano, Hawai’i’, associated with rocks falling onto an active lava lake, which cause resonant oscillations of magma within the conduit and sometimes small but hazardous explosions at the surface. These well-documented natural experiments provide a unique test for models of the shallow conduit and magma reservoir geometry as well as multiphase magma fluid properties. The second goal is to develop a high performance computing-enabled modeling framework to predict transient motions of magma in volcanic conduits under a range of flow conditions, including during explosive eruptions. This work will help bridge the gap between geophysical observations, volcano physics, and advanced computing. The project will support graduate students in interdisciplinary scientific research, and contribute to ongoing development of “The Volcano Listening Project”, an outreach effort dedicated to representing volcano data as sound and animations.This proposal describes a study of small amplitude oscillatory magma flow in volcanic conduits. The first goal is to study short term (tens of minutes) unrest episodes at Kilauea volcano, Hawai’i’, associated with rock falls onto an active lava lake and from rising gas slugs. These disturbances cause ‘very long period’ (VLP, 5−40 s) oscillations of the multi-phase magma within the conduit, explosions, unsteady surface gas flux, and lava lake height variations, recorded on a nearby network of geophysical instruments. These well-documented natural experiments provide a unique test for unsteady conduit flow models, which will be used to invert for subsurface conduit and reservoir geometry as well as magma rheology and primary volatile content. Previous NSF-funded work developed a preliminary framework for modeling and inverting VLP seismic data in terms of the resonant eigenmodes of coupled conduit-reservoir systems, where fluid pressure changes cause elastic deformations of the surrounding solid Earth that are recorded instrumentally. This framework will be applied to thousands of events spanning the ten-year lifespan of the Halema’uma’u vent on Kilauea. Bayesian Markov-Chain Monte Carlo inversions will incorporate constraints from seismicity, ground deformation, continuous gravity, petrologically-determined melt viscosity and volatile content, and lava lake geometry. The second goal is to generate a forward modeling framework to predict wave motion in complex states of magma flow. Modeling relative motion between gas and liquid will predict surface gas flux data during transient unrest events, as well as transient explosions triggered by rockfalls. Wave-like disturbances will also be studied in the context of explosive eruptions, where such oscillatory fluid motions may play a key role in state shifts during eruptions such as the onset of fragmentation and explosive behavior. Flow in volcanic systems is typically not studied at the short timescales proposed here. Explicit consideration of non-equilibrium bubble growth and resorption, complex conduit geometry that includes branching cracks, and stratified, multiphase fluid flow with strong interfaces (such as bubble exsolution or magma fragmentation) is necessary to achieve consistency between multiple geophysical datasets. This approach also permits a critical examination of quasi-steady conduit flow models, which can be shown to be conditionally linearly unstable to perturbations. This suggests a new approach to studying transitions in eruption style. Finally, the study of unstable wave motions in strongly stratified multiphase systems will contribute to numerical method developments with applications beyond volcanology. Numerically resolving flow instabilities using recent developments in provably stable high-order finite difference methods provides a unique opportunity to advance models of volcanic conduit flow, discover new eruptive phenomenology, and connect with volcano monitoring efforts. The project will involve two PhD students at the University of Oregon across Earth Science and Computer Science. Software will be open-source and available to the community. The project team will visit and collaborate with the USGS (Hawaiian Volcano Observatory) to study Kilauea. Ongoing results of modeling and seismic data analysis will be incorporated into public presentations and to “Volcano Listening Project” outreach effort dedicated to representing volcano data as sound and animations.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.

火山爆发和与之相关的人类危害是具有挑战性的预测，因为它们涉及隐藏在地球表面下的岩浆的高度不稳定运动。虽然对推断地下岩浆运动至关重要的观测，如地震活动和次声，越来越多地被收集，但我们缺乏一个理论框架来理解产生这些信号的物理过程。这项工作将研究短时间内火山管道内的岩浆流动，以了解引起各种喷发现象的物理过程。第一个目标是研究夏威夷基拉韦厄基拉韦厄火山的火山活动，与落到一个活跃的熔岩湖上的岩石有关，这会导致管道内岩浆的共振振荡，有时会在表面发生小而危险的爆炸。这些有据可查的自然实验为浅导管和岩浆储层几何形状以及多相岩浆流体性质的模型提供了独特的测试。第二个目标是开发一个高性能的计算支持的建模框架，以预测在一系列流动条件下，包括在爆炸性喷发期间，火山管道中岩浆的瞬态运动。这项工作将有助于弥合地球物理观测、火山物理学和高级计算之间的差距。 该项目将支持研究生进行跨学科科学研究，并促进正在进行的“火山倾听项目”的发展，这是一项致力于将火山数据表现为声音和动画的推广工作，该提案描述了对火山管道中小振幅振荡岩浆流的研究。 第一个目标是研究夏威夷基拉韦厄火山的短期（几十分钟）动荡事件，与罗克瀑布到一个活跃的熔岩湖和上升的气体段塞有关。这些扰动导致管道内多相岩浆的“超长周期”（VLP，5 - 40 s）振荡、爆炸、不稳定的地表气体流量和熔岩湖高度变化，这些都被附近的地球物理仪器网络记录下来。这些有据可查的自然实验为不稳定导管流模型提供了独特的测试，该模型将用于反演地下导管和储层几何形状以及岩浆流变学和初级挥发物含量。以前的NSF资助的工作开发了一个初步的框架，用于建模和反演VLP地震数据的共振本征模式耦合的储层系统，其中流体压力的变化会导致周围的固体地球的弹性变形的仪器记录。这一框架将适用于基拉韦厄上Halema'uma' u喷口十年生命周期内的数千起事件。贝叶斯马尔可夫链蒙特卡罗反演将纳入地震活动性，地面变形，连续重力，岩石学确定的熔体粘度和挥发分含量，熔岩湖的几何形状的约束。第二个目标是生成一个正演模拟框架，以预测复杂状态下岩浆流的波动。 模拟气体和液体之间的相对运动将预测瞬态动荡事件期间的地表气体通量数据，以及由落石引发的瞬态爆炸。波浪状扰动也将在爆炸性喷发的背景下进行研究，这种振荡流体运动可能在喷发期间的状态转变中发挥关键作用，例如破碎和爆炸行为的开始。火山系统中的流动通常不会在这里提出的短时间尺度上进行研究。明确考虑非平衡气泡生长和再吸收，复杂的管道几何形状，包括分支裂缝，分层，多相流体流动与强界面（如气泡出溶或岩浆破碎）是必要的，以实现多个地球物理数据集之间的一致性。 这种方法还允许准稳态管道流模型，可以被证明是有条件的线性不稳定的扰动的关键检查。这为研究火山喷发类型的转变提供了一种新的方法。 最后，在强分层多相系统的不稳定波动的研究将有助于数值方法的发展与火山学以外的应用。使用可证明稳定的高阶有限差分方法的最新发展来数值求解流动不稳定性，为推进火山管道流模型、发现新的喷发现象学以及与火山监测工作相联系提供了一个独特的机会。该项目将涉及俄勒冈州大学地球科学和计算机科学的两名博士生。软件将是开源的，可供社区使用。 项目团队将访问并与美国地质勘探局（夏威夷火山观测站）合作研究基拉韦厄。正在进行的建模和地震数据分析的结果将被纳入公共演讲和“火山倾听项目”的推广工作，致力于将火山数据表示为声音和动画。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知识价值和更广泛的影响审查标准进行评估来支持。

项目成果

A Computational Framework for Time‐Dependent Deformation in Viscoelastic Magmatic Systems

粘弹性岩浆系统中随时间变形的计算框架

• DOI: 10.1029/2022jb024506
• 发表时间: 2022
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Rucker, Cody;Erickson, Brittany A.;Karlstrom, Leif;Lee, Brian;Gopalakrishnan, Jay
• 通讯作者: Gopalakrishnan, Jay

Fluid resonance in elastic-walled englacial transport networks

弹性壁冰川运输网络中的流体共振

• DOI: 10.1017/jog.2021.48
• 发表时间: 2021
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: McQuillan, Maria;Karlstrom, Leif
• 通讯作者: Karlstrom, Leif

Earth Is Noisy. Why Should Its Data Be Silent?

地球很吵闹。

• DOI: 10.1029/2023eo230196
• 发表时间: 2023
• 期刊: Eos
• 作者: Karlstrom, Leif;Holtzman, Ben;Barth, Anna;Crozier, Josh;Pat�, Arthur
• 通讯作者: Pat�, Arthur

History‐Dependent Volcanic Ground Deformation From Broad‐Spectrum Viscoelastic Rheology Around Magma Reservoirs

历史——来自宽谱的依赖火山地面变形——岩浆库周围的粘弹性流变学

• DOI: 10.1029/2022gl101172
• 发表时间: 2023
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Liao, Yang;Karlstrom, Leif;Erickson, Brittany A.
• 通讯作者: Erickson, Brittany A.