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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611943
• 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在时空上都链接。该研究计划的总体目标是了解爆炸性的火山，因为它在岩浆和气体中表达，这些岩浆和气体从地幔通过地壳转向表面和大气。因此，我在此提案中采用了一种一般的“自下而上”方法，说明了如何在单个研究项目中解决和回答特定的关键问题。 该提案的第1部分介绍了岩浆从地幔深度通过地壳到表面的运输，存储和演变。特别关注不同批次的岩浆，它们如何和地点存储在地壳储层中，以及在火山喷发前后不同批次相互作用的手段和时机。我将检查小型系统（冰岛的Hekla和尼加拉瓜的Cerro Negro）以及更大的火山口系统。 补充提案的第一部分，第2部分检查了火山气体从地幔到表面的同位素进化。这些将是同类同位素的第一个同位素测量。该研究的第一个组成部分将检查在积极脱气的火山羽毛中火山气的碳同位素特征。第二个成分将研究熔体夹杂物中的碳和氢同位素，以深入了解火山下更深层次的同位素气体特征。 第3部分将使用两种新方法研究火山气体排放的大气和环境影响。首先，将计算铜，碘和氯预算，以估算在大型爆炸性喷发期间释放的这些挥发性物种的数量，这些爆炸性可能有助于复制平流层臭氧。其次，受火山脱水影响的树环的硫同位素特征将用于识别火山的活性和静止期。这样的同位素树环记录提供了一种在火山上识别和定期重新激活的火山约会活动的新方法。 在这项为期5年的研究课程期间，将对总共3名博士生，3名MSC学生，10名BSC学生和1名博士后学生进行培训。我的心理理念是确保越来越多的初中生受到我自己和更多的高年级学生的指导和培训，尤其是博士后和高级博士生。 这项研究将有助于我的长期目标，这是对爆发前后岩浆和挥发性行为的广泛理解。获得的知识将提高我们预测火山喷发的能力。