Collaborative Research: Dynamics of caldera-scale rhyolitic magma systems

合作研究：破火山口规模流纹质岩浆系统的动力学

• 批准号: 1411779
• 负责人: Bradley Singer
• 金额: $ 223.31万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1411779&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamics; caldera; scale

The objective of this project is to build a new understanding of the dynamic processes that create large rhyolitic magma systems and drive them into states of unrest and potential eruption. The natural laboratory at the Laguna del Maule volcanic field (LdM) in the Southern Andes of Chile presents a remarkable opportunity to investigate system dynamics while magma migration, reservoir growth, and crustal deformation are currently underway. This project will: (1) Ascertain the cause of the ongoing episode of unrest, including: (a) gauging the dimensions, depth, and melt fraction of the magma body or bodies currently beneath LdM; (b) estimating how these parameters evolve with time, and (c) assessing whether both current deformation, and longer term, ~20,000 year, uplift, reflects replenishment of the system with basalt; (2) Integrate petrologic and geochronologic data to track and model crystallization, cooling, magma mixing and heating events over the past ~100,000 years, and to determine whether the eruptive flare-up of rhyolitic lavas during the last 25,000 years shares a common, shallow source of melt or has more diffuse origins deeper in the crust; and (3) Create coupled numerical models that will link the observations to the physics and chemistry of the multi-phase magma-crust system over a variety of timescales. Since Earth will eventually experience another caldera-forming rhyolitic eruption, there is a need to gather comprehensive information and create models that realistically account for the dynamics that lead to these destructive events. Meeting this challenge will require understanding: (1) the slow geologic processes, magmatic conditions, and structural changes that propel assembly and growth of these systems, and (2) the dynamics of a complex multiphase system on both long (years to millennia), and short (days to months) human time scales. A firm grasp on the coupling among these processes is currently lacking because they operate on scales ranging over many orders of magnitude temporally and spatially. This project affords a unique opportunity to investigate the dynamics of such a system while magma migration, reservoir growth, and astonishing crustal deformation are currently underway. Exploring this frontier through both observations and novel modeling approaches will yield unprecedented insight into system dynamics.

该项目的目标是对形成大型流纹岩浆系统并使其进入不稳定和潜在喷发状态的动态过程建立新的认识。智利安第斯山脉南部拉古纳德尔莫莱火山田 (LdM) 的自然实验室为研究目前正在进行的岩浆迁移、储层生长和地壳变形过程中的系统动力学提供了绝佳的机会。该项目将： (1) 查明持续骚乱的原因，包括： (a) 测量目前位于 LdM 下方的岩浆体的尺寸、深度和熔化分数； (b) 估计这些参数如何随时间演变，以及 (c) 评估当前变形和长期约 20,000 年的隆起是否反映了系统玄武岩的补充； (2) 整合岩石学和地质年代学数据，跟踪和模拟过去约 10 万年的结晶、冷却、岩浆混合和加热事件，并确定过去 25,000 年流纹质熔岩的喷发是否具有共同的、浅层的熔体来源或在地壳深处具有更分散的起源； (3) 创建耦合数值模型，将观测结果与不同时间尺度的多相岩浆-地壳系统的物理和化学联系起来。由于地球最终将经历另一次形成火山口的流纹岩喷发，因此需要收集全面的信息并创建模型来真实地解释导致这些破坏性事件的动力学。应对这一挑战需要了解：（1）推动这些系统组装和生长的缓慢地质过程、岩浆条件和结构变化，以及（2）复杂多相系统在长期（数年到数千年）、和短（几天到几个月）的人类时间尺度。 目前还缺乏对这些过程之间耦合的牢固把握，因为它们在时间和空间上的范围内运行多个数量级。该项目提供了一个独特的机会来研究这种系统的动力学，同时岩浆迁移、储层生长和惊人的地壳变形正在进行。 通过观察和新颖的建模方法探索这一前沿领域将产生对系统动力学前所未有的洞察。

项目成果

Teleseismic Tomography of the Laguna del Maule Volcanic Field in Chile

• DOI: 10.1029/2020jb019449
• 发表时间: 2020-08
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Tong Bai;C. Thurber;F. Lanza;B. Singer;N. Bennington;K. Keranen;C. Cardona

Magma Reservoir Below Laguna del Maule Volcanic Field, Chile, Imaged With Surface‐Wave Tomography

• DOI: 10.1029/2018jb016485
• 发表时间: 2019-03
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: C. Wespestad;C. Thurber;N. Andersen;B. Singer;C. Cardona;Xiangfang Zeng;N. Bennington;K. Keranen;D. Peterson;Darcy Cordell;M. Unsworth;C. Miller;G. Williams-Jones