Computational simulations of volcanic eruptions and infrasound

火山喷发和次声的计算模拟

• 批准号: 1930979
• 负责人: Eric Dunham
• 金额: $ 20.05万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-15 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1930979&HistoricalAwards=false
• 关键词: Computational; simulations; volcanic; eruptions; infrasound

Volcanic eruptions generate sound waves in the atmosphere and seismic waves in the solid Earth. These waves can be recorded at a safe distance from volcanoes and used to constrain eruptive processes that are otherwise obscured from study. This project will develop computer simulations of magma ascent through volcanic conduits in the solid Earth and eruption into the atmosphere that also capture sound and seismic waves. Most current eruption simulations are based on simplifying approximations, like incompressible fluids and rigid solids, that eliminate waves. Simulation results from the project can be used to improve volcano monitoring, data interpretation, and hazard assessment. The project will provide training for a PhD student and postdoctoral scholar, and outreach activities for the general public include volcano-related demos at local elementary school science nights, STEMTaught articles for an elementary-school-level textbook meeting the Next Generation Science Standards, and a Stanford Ask A Scientist webpage.The eruption simulations will utilize a state-of-the-art aeroacoustics code originally designed to study sound radiation by turbulent jets and shocks created by discharge of high pressure gas from jet engines. The code will be modified to study volcanic eruptions by coupling to an unsteady conduit flow code that models the ascent, depressurization, and fragmentation of magma. Simulations of vulcanian and strombolian eruptions will be used to 1.) assess the validity of commonly used acoustic source models like the point monopole and linear acoustics; 2.) quantify the effects of turbulent entrainment on infrasound generation (facilitating joint interpretation of visual and infrasound data); and 3.) probe subsurface eruptive processes like the rate of depressurization of shallow reservoirs, providing insight into how gas and magma are temporarily stored, pressurized, and released near the vent; also, identify signatures of the descent of the fragmentation surface down the conduit in large vulcanian explosions. Seismic representation theory will be used to convert pressure and momentum changes within the conduit to equivalent seismic moment tensor and force sources in the elastic wave equation. Seismic constraints on eruptive processes like fragmentation will be derived to complement infrasound constraints. This project is supported by the Geophysics and Petrology/Geochemistry programs.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.

火山喷发会在大气中产生声波，并在固体地球上产生震动波。这些波可以在与火山的安全距离处记录，并用于限制否则研究中掩盖的喷发过程。该项目将通过固体地球中的火山导管开发岩浆上升的计算机模拟，并爆发到大气中，这也捕获了声音和地震波。当前大多数喷发模拟基于简化近似值，例如不可压缩的流体和刚性固体，从而消除了波浪。该项目的仿真结果可用于改善火山监测，数据解释和危害评估。该项目将为博士生和博士后学者提供培训，并为公众提供宣传活动包括在当地小学科学之夜与火山相关的演示，为符合下一代科学标准的基础学校的文章提供了茎的文章，以及斯坦福以及通过喷气发动机排放高压气体产生的冲击。该代码将通过与不稳定的导管流量代码耦合来修改以研究火山喷发，该导管流量代码对岩浆的上升，抑郁和碎片进行建模。对瓦坎尼亚和斯特朗博利亚喷发的模拟将用于1。）评估常用声源模型（如点单极和线性声学）的有效性； 2.）量化湍流夹带对临界产生的影响（促进视觉和非传动数据的联合解释）； 3.）探针地下喷发过程，例如浅储层的降压率，提供有关如何临时存储，加压和在通风口附近释放的气体和岩浆的见解；另外，在大型瓦坎尼亚爆炸中，确定碎裂表面下降的特征。地震表示理论将用于将导管内的压力和动量变化转换为弹性波方程中等效的地震矩张量和力源。诸如碎裂之类的喷发过程的地震限制将得出以补充侵权约束。该项目得到了地球物理和质学/地球化学计划的支持。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响标准，被认为值得通过评估来获得支持。

项目成果

Infrasound Radiation from Impulsive Volcanic Eruptions: Nonlinear Aeroacoustic 2D Simulations

脉冲火山喷发的次声辐射：非线性气动声学二维模拟

• 发表时间: 2021
• 期刊: Journal of geophysical research
• 作者: Watson, Leighton M.;Dunham, Eric M.;Mohaddes, Danyal;Labahn, Jeff;Jaravel, Thomas;Ihme, Matthias
• 通讯作者: Ihme, Matthias

Ultra and Very Long Period Seismic Signatures of Unsteady Eruptions Predicted From Conduit Flow Models

根据管道流模型预测的不稳定喷发的超长周期地震特征

• DOI: 10.1029/2022jb024313
• 发表时间: 2022
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Coppess, Katherine R.;Dunham, Eric M.;Almquist, Martin
• 通讯作者: Almquist, Martin

Physics‐Based Model Reconciles Caldera Collapse Induced Static and Dynamic Ground Motion: Application to Kīlauea 2018

基于物理的模型协调了火山口塌陷引起的静态和动态地面运动：应用于 Kä«lauea 2018

• DOI: 10.1029/2021gl097440
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Wang, Taiyi A.;Coppess, Katherine R.;Segall, Paul;Dunham, Eric M.;Ellsworth, William
• 通讯作者: Ellsworth, William