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: 1411724
• 负责人: Josef Dufek
• 金额: $ 35.46万
• 依托单位: Georgia Tech Research Corporation
• 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 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1411724&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.

该项目的目标是建立一个新的认识的动态过程，创造大型流纹岩岩浆系统，并推动他们进入动荡和潜在的喷发状态。在智利南部安第斯山脉的拉古纳德尔马乌莱火山区（LdM）的天然实验室提供了一个显着的机会，研究系统动力学，而岩浆迁移，水库生长，地壳变形目前正在进行中。该项目将：（1）确定正在发生的不稳定事件的原因，包括：（a）测量目前在LdM下面的岩浆体的尺寸、深度和熔融部分;（B）估计这些参数如何随时间演变，以及（c）评估目前的变形和较长期（约20，000年）的隆起是否反映了玄武岩对系统的补充;（2）整合岩石学和地质年代学数据，追踪和模拟过去~ 100，000年来的结晶、冷却、岩浆混合和加热事件，并确定过去25，000年流纹岩熔岩的喷发是否有共同的浅源。熔体或在地壳深处具有更分散的起源;（3）建立耦合的数值模型，将观测结果与不同时间尺度上多相岩浆-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，以现实地解释导致这些破坏性事件的动力学。迎接这一挑战将需要理解：（1）缓慢的地质过程，岩浆条件和结构变化，推动这些系统的组装和生长，以及（2）复杂的多相系统在长（几年到几千年）和短（几天到几个月）人类时间尺度上的动力学。 目前缺乏对这些过程之间的耦合的牢固把握，因为它们在时间和空间上的尺度范围超过许多数量级。这个项目提供了一个独特的机会，调查这样一个系统的动力学，而岩浆迁移，储层生长，和惊人的地壳变形目前正在进行中。 通过观察和新的建模方法探索这一前沿将产生前所未有的洞察系统动力学。