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.

火山喷发及其与之相关的人类危害受到挑战，因为它们涉及隐藏在地球表面下方的岩浆的高度不稳定运动。尽管对推断地下岩浆运动（例如地震性和侵权）至关重要的观察结果越来越多地收集，但我们缺乏理论框架来理解产生此类信号的物理过程。这项工作将是对短时间火山导管中岩浆流的研究，以了解产生各种喷发现象的物理过程。第一个目标是在夏威夷'的基拉韦阿火山上研究火山活动，与岩石落在一个活跃的熔岩湖上有关，这会导致导管内岩浆的担忧振荡，有时在地面上造成了较小但危险的爆炸。这些有据可查的自然实验为浅水管和岩浆储层几何形状以及多相岩浆流体特性的模型提供了独特的测试。第二个目标是开发一个高性能计算的建模框架，以在一系列流动条件下（包括爆炸性爆发期间）预测火山导管中岩浆的短暂运动。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跨学科科学研究，并为“火山聆听项目”的持续发展做出贡献，该计划致力于将火山数据表示为声音和动画。该提案描述了一项小型放大器振动性振荡岩浆流量的研究。第一个目标是在夏威夷'Kilauea Volcano’的短期（数十分钟）动乱发作，与岩石有关，落在一个活跃的熔岩湖上，并从升起的气体slugs掉。这些灾难引起了“非常长的时间”（VLP，5-40 s）在导管中的多相岩浆，爆炸，不稳定的表面气通量和熔岩湖高度变化，记录在近地球物质仪器网络上。这些有据可查的自然实验为不稳定的导管流模型提供了独特的测试，该测试将用于倒入地下导管和储层几何形状以及岩浆流变学和初级挥发性含量。以前的NSF资助的工作开发了一个初步框架，用于建模和反相VLP地震数据，以耦合的导管储层系统的共振特征模型，其中流体压力变化会导致周围固体地球的弹性变形，这些固体地球被记录为仪器。该框架将应用于跨越Kilauea的Halema’uma’u Vent十年寿命的成千上万事件。贝叶斯马尔可夫链蒙特卡洛倒置将纳入地震性，地面变形，连续重力，岩石学确定的熔体粘度和挥发性含量的限制，以及熔岩湖的几何形状。第二个目标是生成一个正向建模框架，以预测岩浆流的复杂状态的波动运动。对气体和液体之间的相对运动进行建模将预测瞬态动荡事件期间的表面气体通量数据，以及落石触发的瞬态爆炸。在爆炸性爆发的背景下，类似波浪状的灾难也将研究，在这种爆炸性爆发的背景下，这种振荡的流体运动在诸如碎片化和爆炸性行为之类的喷发过程中可能在状态转移中起关键作用。火山系统中的流量通常在此处提出的短时间内没有研究。明确考虑非平衡气泡生长和分辨率，包括分支裂纹的复杂导管几何形状以及具有强界面的分层，多相流体流量（例如气泡ExSolution或Magma碎片化）对于达到多个地球物理数据集之间的一致性是必要的。这种方法还允许对准稳态导管流模型进行批判性检查，该模型可以证明对扰动有条件地线性不稳定。这暗示了一种新的方法来研究喷发风格的过渡。最后，对强大分层的多相系统中不稳定波动运动的研究将有助于数值方法的发展，其应用超出了火山学。在可能的稳定高阶有限差异方法中使用最新发展的数值解决流动不便，为推进火山导管流的模型，发现新的喷发现象学并与火山监测工作建立联系提供了独特的机会。该项目将涉及俄勒冈大学的两名博士学位学生在地球科学和计算机科学上。软件将是开源的，并可以向社区使用。项目团队将访问并与USGS（夏威夷火山天文台）合作学习Kilauea。持续的建模和地震数据分析结果将纳入公开演讲中，并将“火山听力项目”的外展工作纳入专门用于将火山数据表示为声音和动画的范围。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的审查审查标准来通过评估来通过评估来支持的。

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

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.

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