Magmatic volatiles and degassing from the Earth

岩浆挥发物和地球脱气

• 批准号: RGPIN-2020-04197
• 负责人: Stix, John
• 金额: $ 3.13万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=751018
• 关键词: Magmatic; volatiles; degassing; Earth

This proposal examines the nature, origin, and transport of magmatic volatile elements in influencing and controlling volcanic activity, especially the style and size of violent explosive eruptions which pose a major threat to millions of people worldwide. My goal is to use a series of new and novel tools and approaches which together will propel our understanding of how, when, and why volcanoes erupt. The research is designed to examine volatiles through a vertical section of the shallow Earth system, moving from crustal conditions where volatiles are stored and transported upward, through the near surface where magmatic volatiles interact with shallow groundwater and hydrothermal systems, to the surface where the volatiles emerge as volcanic gas. The first component of the research will use nominally anhydrous minerals (NAM's), which contain small amounts of water, to understand the behaviour of magmatic water in the shallow crust, including its accumulation and loss (degassing). Two systems will be studied in detail, one basaltic (Stromboli, Italy) and one silicic (Toledo caldera, New Mexico, USA). The second component of the research is to understand phreatic eruptions, which are commonly driven by inputs of magmatic gas into shallow hydrothermal systems. I will design, build, and use a new CH4-CO2-H2S MultiGas instrument (first of its kind) to measure the CH4/CO2 gas ratio, which provides a monitor of hydrothermal and magmatic interactions. I will also conduct a field experiment at Rincón de la Vieja volcano in Costa Rica, where phreatic eruptions are common. I will conduct a series of real-time gas, seismic, and deformation measurements before during, and after phreatic eruptions. Last, I will study a suite of hydrothermal breccias at Turrialba volcano, Costa Rica, to determine the nature of sealing and unsealing processes associated with phreatic eruptions and the underlying magmatic-hydrothermal system. The final component of this research is to characterize volcanic plumes isotopically on a near real-time basis, to evaluate spatial and temporal changes in relation to eruptions. The isotopic systems include d13C in CO2, d13C in CH4, and dD and d18O in water. In terms of highly qualified personnel (HQP), I will train a total of 13 students (6 MSc-PhD-PDF and 7 BSc). In terms of equity, diversity, and inclusion (EDI), gender balance for my students over the past six year has been 56% male and 44% female, and currently it is 43% male and 57% female, with two students from other under-represented groups. My EDI efforts include maintaining gender balance, targeted recruiting, and outreach.

这一建议审查了岩浆挥发性元素的性质、起源和迁移，以影响和控制火山活动，特别是对全世界数百万人构成重大威胁的猛烈爆炸性喷发的类型和规模。我的目标是使用一系列新的和新颖的工具和方法，这些工具和方法将共同推动我们对火山爆发的方式，时间和原因的理解。这项研究旨在通过浅层地球系统的垂直剖面来研究挥发物，从挥发物储存和向上输送的地壳条件，通过岩浆挥发物与浅层地下水和热液系统相互作用的近地表，到挥发物作为火山气体出现的地表。研究的第一部分将使用含有少量水的名义上无水矿物（NAM），以了解地壳浅层岩浆水的行为，包括其积累和损失（脱气）。两个系统将被详细研究，一个玄武岩（斯特龙博利，意大利）和一个火山（托莱多火山口，新墨西哥州，美国）。研究的第二个组成部分是了解潜水喷发，这通常是由岩浆气体输入到浅层热液系统驱动的。我将设计，建造和使用一个新的CH 4-CO2-H2S MultiGas仪器（同类仪器中的第一个）来测量CH 4/CO2气体比率，这提供了热液和岩浆相互作用的监测。我还将在哥斯达黎加的林孔德拉韦哈火山进行实地实验，那里经常发生潜水喷发。我将进行一系列的实时气体，地震和变形测量之前，期间，和之后的潜水喷发。最后，我将研究一套热液角砾岩在图里亚尔瓦火山，哥斯达黎加，以确定封闭和解封过程的性质与潜水喷发和下伏的岩浆热液系统。这项研究的最后一个组成部分是在近实时的基础上对火山羽流进行同位素鉴定，以评价与喷发有关的空间和时间变化。同位素体系包括CO2中的d13 C、CH 4中的d13 C以及水中的dD和d18 O。在高素质人才（HQP）方面，我将培养13名学生（6名MSc-PhD-PDF和7名BSC）。在公平，多样性和包容性（EDI）方面，在过去的六年里，我的学生的性别平衡一直是56%男性和44%女性，目前是43%男性和57%女性，有两名学生来自其他代表性不足的群体。我的EDI工作包括保持性别平衡，有针对性的招聘和推广。