Transport of magma and gas from the mantle to the atmosphere by volcanic eruptions

通过火山喷发将岩浆和气体从地幔输送到大气中

• 批准号: RGPIN-2014-05955
• 负责人: Stix, John
• 金额: $ 6.48万
• 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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=692384
• 关键词: Transport; magma; gas; mantle; atmosphere

This proposal comprises six distinct projects which are linked intellectually and also in time and space. The overarching objective of this research program is to understand explosive volcanism as it is expressed in magmas and gases which transit from the mantle through the crust to the surface and atmosphere. As such, I take a general "bottom-to-top" approach within this proposal, illustrating how specific key problems can be addressed and answered within the individual research projects.**Part 1 of the proposal addresses the transport, storage, and evolution of magmas from mantle depths through the crust to the surface. Particular attention is paid to distinct batches of magmas, how and where they are stored in crustal reservoirs, and the means and timing by which the different batches interact prior to and during volcanic eruptions. I will examine both small systems (Hekla in Iceland and Cerro Negro in Nicaragua) as well as larger caldera systems.**Complementary to the first part of the proposal, Part 2 examines the isotopic evolution of volcanic gas from the mantle to the surface. These will be the first such isotopic measurements of their kind. The first component of the research will examine the carbon isotopic character of volcanic gas in plumes of actively degassing volcanoes. The second component will study carbon and hydrogen isotopes in melt inclusions to gain insight into isotopic gas signature of gas at deeper levels beneath a volcano.**Part 3 will study the atmospheric and environmental effects and impacts of volcanic gas emissions using two new approaches. First, the bromine, iodine, and chlorine budget of caldera supervolcanoes will be calculated, to estimate the amount of these volatile species released during large explosive eruptions which may serve to deplete stratospheric ozone. Second, the sulfur isotopic signature of tree rings impacted by volcanic degassing will be used to identify periods of activity and quiescence at volcanoes. Such isotopic tree ring records offer a new means of identifying and dating activity at volcanoes which reactivate periodically. **A total of 3 PhD students, 3 MSc students, 10 BSc students, and 1 postdoctoral student will be trained during the course of this 5-year research program. My mentoring philosophy is to ensure that the more junior students are mentored and trained by myself and the more senior students, in particular the postdoc and advanced PhD students.**This research will contribute to my long-term goals which are a broad understanding of magma and volatile behaviour prior to and during eruptions. The knowledge gained will improve our ability to forecast volcanic eruptions.

该提案包括六个不同的项目，这些项目在智力上以及时间和空间上都有联系。该研究计划的总体目标是了解爆发性火山活动，因为它是在岩浆和气体从地幔通过地壳到表面和大气的过境表示。因此，我在这个建议中采取了一种一般的“自下而上”的方法，说明了如何在各个研究项目中解决和回答具体的关键问题。提案的第一部分涉及岩浆从地幔深处通过地壳到地表的运输、储存和演化。特别注意的是不同批次的岩浆，它们是如何和在哪里存储在地壳水库，以及不同批次的火山爆发之前和期间相互作用的手段和时间。我将研究两个小系统（冰岛的Hekla和尼加拉瓜的Cerro Negro）以及较大的破火山口系统。作为对第一部分建议的补充，第二部分研究了从地幔到地表的火山气体的同位素演化。这将是此类同位素测量的第一次。研究的第一个组成部分将审查积极脱气火山羽流中火山气体的碳同位素特征。第二部分将研究熔融包裹体中的碳和氢同位素，以深入了解火山下方更深层次的气体同位素气体特征。第三部分将采用两种新方法研究火山气体排放对大气和环境的影响。首先，将计算破火山口超级火山的溴、碘和氯的收支，以估计可能消耗平流层臭氧的大型爆炸性喷发过程中释放的这些挥发性物质的数量。第二，受火山脱气影响的树木年轮的硫同位素特征将用于确定火山的活动和静止期。这种同位素树木年轮记录提供了一种新的方法来识别和确定定期重新活跃的火山活动的年代。** 共有3名博士生，3名硕士生，10名学士生和1名博士后学生将在这个为期5年的研究计划的过程中进行培训。我的指导理念是确保更多的初级学生由我和更高年级的学生指导和培训，特别是博士后和高级博士生。这项研究将有助于我的长期目标，这是一个广泛的了解岩浆和挥发性行为之前和期间爆发。所获得的知识将提高我们预测火山爆发的能力。