Insights into Episodic Caldera Collapse and Magmatic Systems from the 2018 Eruption of Kilauea Volcano

从 2018 年基拉韦厄火山喷发洞察火山口火山口崩塌和岩浆系统

• 批准号: 2040425
• 负责人: Paul Segall
• 金额: $ 47万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2040425&HistoricalAwards=false
• 关键词: Insights; into; Episodic; Caldera; Collapse

Volcanic caldera collapse occurs when large volumes of magma erupt rapidly, causing the overlying the crust to founder into the subterranean magma chamber. Caldera collapse occurs during both explosive and lava flow forming eruptions; both are fortunately relatively rare. The 2018 eruption of Kīlauea volcano in Hawai‘i destroyed 700 homes and led to $800 million in damage. The associated caldera collapse was by far the best monitored in history. In 2.5 months, the floor of the centuries-old caldera, within Hawai‘i Volcanoes National Park, dropped up to 500 meters and increased in volume by 0.8 km3. It is crucial to understand the collapse process because the weight of the overlying crust acts to sustain these eruptions. While the basics of caldera collapse are understood, the unprecedented data collected in 2018 will allow us to address first order questions, including: What are the crustal stress and magma pressure conditions necessary for collapse? What is the sub-surface geometry of the ring fault system bounding the collapse? Why did collapse occur in discrete events, and what physical properties controlled the character of these events? What is the nature of sub-caldera magma storage systems and how do they connect to the eruptive vents? Modeling of these unique data will lead to a quantitative leap in our understanding of caldera collapse. The project will support a graduate student to understand volcanic hazards in the U.S.The 2018 collapse of occurred in 62 discrete events in which the caldera dropped from several to nearly 10 meters, accompanied by magnitude 5.2 to 5.4 earthquakes. Collapses were accompanied by remarkable, inflationary deformation offsets followed by decelerating deflations, similar to behavior at other basaltic caldera collapses. There has been considerable debate as to whether caldera ring-faults are inward or outward dipping. This project will use finite element (FEM) modeling combined with inversion of high-rate GPS data to constrain the ring-fault dip and the compressibility, and hence vesicularity, of the underlying magma. The research will further use pre- co-, and in particular post-collapse GPS and InSAR data to constrain the geometry, size and connectivity of the enigmatic summit magma system. The dynamics of collapse are analyzed with a model in which the weight of the caldera block is balanced by magma pressure at its base and rate-and-state dependent friction on its sides. Flow of magma is driven by the pressure difference between the magma chamber and the eruption site. Model predictions of repeated collapse events are compared to the time between events, their duration, displacement, and magma chamber pressure increase. The model elucidates the conditions for caldera collapse, and how collapse sustains eruptions that would otherwise cease. The measured surges in eruptive flux will be used to further constrain pressures within the magma system. Our analysis of co-collapse deformation leads naturally to a model for the VLP earthquakes. Synthetic waveforms will be computed that can be compared to low-pass filtered seismic observations. A striking correlation of cumulative VT seismicity with inter-collapse subsidence strongly suggests fault creep on the ring-fault prior to collapse, providing insights into fault development and chamber pressure history.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.

当大量岩浆迅速爆发时，火山火山口塌陷就会发生，从而导致外壳进入创始人进入地下岩浆室。在爆炸和熔岩流形成爆发期间，火山口塌陷发生。幸运的是，两者都相对罕见。 2018年夏威夷的基拉乌亚火山爆发摧毁了700栋房屋，并造成了8亿美元的损失。迄今为止，相关的火山口崩溃是历史上最好的监测。在2.5个月内，夏威夷火山国家公园内的数百年历史的火山口的地板下降了500米，体积增加了0.8 km3。了解崩溃过程至关重要，因为上覆的外壳的重量是维持这些喷发的。尽管了解了Caldera崩溃的基础知识，但2018年收集的前所未有的数据将使我们能够解决一阶问题，包括：倒塌所需的地壳压力和岩浆压力条件是什么？环形故障系统的地下几何形状是什么？为什么在离散事件中发生崩溃，以及哪些物理属性控制着这些事件的特征？亚电压岩浆存储系统的性质是什么，它们如何连接到喷发通风口？这些独特数据的建模将导致我们对火山口倒塌的理解的定量飞跃。该项目将支持一名研究生了解美国2018年的火山危害发生在62次离散事件中，其中火山口从几米下降到近10米，以5.2级至5.4地震完成。倒塌是通过出色的通货膨胀变形偏移来完成的，然后减速，与其他玄武岩崩溃的行为相似。关于火山口戒指是内向还是向外浸出，已经进行了相当大的调试。该项目将使用有限元（FEM）建模与高速GPS数据的反转来限制基础岩浆的兼容性以及囊泡性。这项研究将进一步使用前co-，尤其是爆发后的GPS和INSAR数据来限制神秘峰会岩浆系统的几何形状，大小和连通性。用一个模型分析了崩溃的动力学，在该模型中，火山口块的重量在其侧面的岩浆压力和速率和状态依赖性摩擦的侧面平衡。岩浆的流动是由岩浆室和喷发部位之间的压力差驱动的。将重复崩溃事件的模型预测与事件之间的时间，持续时间，位移和岩浆腔室压力增加进行比较。该模型阐明了火山口塌陷的条件，以及塌陷如何保持爆发，原本会停止。喷发通量中测得的潮流将用于进一步限制岩浆系统内的压力。我们对共发变形的分析自然导致了VLP地震的模型。将计算合成波形，可以将其与低通滤波的地震观测值进行比较。累积VT地震性与崩溃间沉降的显着相关性强烈表明，在崩溃之前，错误的错误爬行，提供了对故障发展和室内压力历史的见解。该奖项反映了NSF的法定任务，并且我们是否通过使用该基金会的知识分子优点和广泛的影响来评估我们的支持诚实地，我们被认为是诚实的。

项目成果

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

Repeating caldera collapse events constrain fault friction at the kilometer scale

• DOI: 10.1073/pnas.2101469118
• 发表时间: 2021-07
• 期刊: Proceedings of the National Academy of Sciences
• 作者: P. Segall;K. Anderson

Post‐2018 Caldera Collapse Re‐Inflation Uniquely Constrains Kīlauea's Magmatic System

2018 年火山口崩塌后的通货膨胀再次制约了凯劳厄亚的岩浆系统

• DOI: 10.1029/2021jb021803
• 发表时间: 2021
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Wang, Taiyi;Zheng, Yujie;Pulvirenti, Fabio;Segall, Paul
• 通讯作者: Segall, Paul

Could Kı̄lauea's 2020 Post Caldera‐Forming Eruption Have Been Anticipated?

Kä±Ìlauea 2020 年火山口形成后的喷发是否已被预料到？

• DOI: 10.1029/2022gl099270
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Segall, Paul;Anderson, Kyle;Wang, Taiyi A.
• 通讯作者: Wang, Taiyi A.