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: 1841375
• 负责人: Josef Dufek
• 金额: $ 11.23万
• 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: 2018
• 资助国家: 美国
• 起止时间: 2018-05-16 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1841375&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.

该项目的目的是建立对创建大型流纹岩浆系统的动态过程的新理解，并将它们推向动荡和潜在喷发的状态。智利安第斯山脉南部拉古纳德莫勒火山场（LDM）的自然实验室为研究系统动态提供了一个了不起的机会，而岩浆迁移，储层生长和地壳变形目前正在进行中。该项目将：（1）确定动乱正在进行的事件的原因，包括：（a）衡量当前LDM下面的岩浆身体或尸体的尺寸，深度和熔体部分； （b）估计这些参数如何随时间演变，（c）评估当前变形和长期〜20,000年，抬高，反映了该系统用玄武岩的补充； （2）在过去〜100，000年中，将岩石学和测量数据集成以跟踪和模型结晶，冷却，岩浆混合和加热事件，并确定在过去25，000年中的流纹岩熔岩的爆发是否爆发是一种常见的，浅的融化来源，还是在构造中具有更大的弥漫性来源。 （3）创建耦合的数值模型，将观测值与多种时间尺度上的多相岩浆系统的物理和化学联系起来。由于地球最终将经历另一种形成火山口的节纹性喷发，因此有必要收集全面的信息并创建模型，以实际考虑导致这些破坏性事件的动态。应对这一挑战将需要理解：（1）促进这些系统的组装和增长的缓慢地质过程，岩浆条件和结构变化，以及（2）长期（到几年到几年）和短期（天到几个月）人类时间量表的复杂多相系统的动态。 目前缺乏对这些过程之间的耦合的坚定掌握，因为它们在时间和空间上在许多数量级的尺度上运行。该项目为研究这种系统的动态提供了一个独特的机会，而岩浆迁移，储层增长和惊人的地壳变形目前正在进行中。 通过观察和新颖的建模方法探索这种领域将产生对系统动力学的前所未有的见解。