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.

当大量岩浆快速喷发时，火山口塌陷就会发生，导致上覆地壳沉入地下岩浆库，火山口塌陷发生在爆炸性喷发和熔岩流形成的喷发过程中；幸运的是，2018 年基拉韦厄火山的喷发相对罕见。夏威夷摧毁了 700 所房屋，造成了 8 亿美元的损失，与之相关的火山口崩塌是迄今为止监测得最彻底的一次。 2.5 个月内，夏威夷火山国家公园内具有数百年历史的火山口底部下降了 500 米，体积增加了 0.8 平方公里。了解塌陷过程至关重要，因为上覆地壳的重量会影响火山口的塌陷。虽然火山口塌陷的基本原理已被了解，但 2018 年收集到的前所未有的数据将使我们能够解决首要问题，包括：地壳应力和岩浆压力条件是什么。塌陷所必需的环形断层系统的地下几何形状是什么？为什么在离散事件中发生塌陷，以及哪些物理特性控制了这些事件的特征？火山口下岩浆储存系统的性质是什么？它们如何与喷发口联系起来？对这些独特数据的建模将导致我们对火山口塌陷的理解发生质的飞跃。该项目将支持研究生了解美国发生的火山灾害。在 62 个离散事件中，火山口从几米下降到近 10 米，伴随着 5.2 至 5.4 级地震，塌陷伴随着显着的膨胀变形抵消，随后是减速的通货紧缩，类似于其他玄武岩火山口塌陷的行为。关于破火山口环断层是向内倾斜还是向外倾斜存在相当大的争议，该项目将使用有限元（FEM）建模与高速率反演相结合。 GPS 数据来限制环断层倾角和可压缩性，从而限制底层岩浆的气泡性。该研究将进一步使用塌陷前、特别是塌陷后的 GPS 和 InSAR 数据来限制几何形状、大小和连通性。通过模型分析了神秘的山顶岩浆系统的崩塌动力学，其中火山口块的重量由其底部的岩浆压力和其两侧的速率和状态相关的摩擦力来平衡。将岩浆室和喷发地点之间的压力差与事件之间的时间、持续时间、位移和岩浆室压力增量进行比较，该模型阐明了火山口塌陷的条件以及塌陷如何持续。测得的喷发通量激增将用于进一步限制岩浆系统内的压力，我们对共塌陷变形的分析自然会产生 VLP 地震模型。计算出的波形可与低通滤波地震观测结果进行强烈比较，累积 VT 地震活动与塌陷间沉降的显着相关性表明，在塌陷之前，环形断层上的断层蠕变，为断层发育和腔室压力历史提供了见解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

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: 2022-08
• 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.

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: 2022-04
• 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

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: 2021-06
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Wang, Taiyi;Zheng, Yujie;Pulvirenti, Fabio;Segall, Paul
• 通讯作者: Segall, Paul

Halofuginone — The Multifaceted Molecule

卤常酮 — 多面分子

• DOI: 10.3390/molecules20010573
• 发表时间: 2015-01-05
• 期刊: Molecules
• 影响因子: 4.6
• 作者: Pines M;Spector I
• 通讯作者: Spector I