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

这项提案包括六个不同的项目，它们在智力上以及在时间和空间上都有联系。这一研究计划的首要目标是了解火山爆发，因为它表现在从地幔通过地壳传递到地表和大气的岩浆和气体中。因此，我在这项建议中采取了一般的“自下而上”的方法，说明了如何在个别研究项目中解决和回答具体的关键问题。该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。特别注意不同批次的岩浆，它们在地壳储集层中的储存方式和位置，以及不同批次的岩浆在火山喷发之前和期间相互作用的方式和时间。我将研究两个小系统(冰岛的Hekla和尼加拉瓜的Cerro Nero)以及较大的火山口系统。作为对提议的第一部分的补充，第二部分研究了火山气体从地幔到地表的同位素演化。这将是此类同位素测量的第一次。这项研究的第一部分将检查活跃的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深层气体的同位素气体特征。第三部分将使用两种新的方法研究火山气体排放对大气和环境的影响和影响。首先，将计算破火山口超级火山的溴、碘和氯的收支平衡，以估计在大规模爆炸性喷发期间释放的这些挥发性物质的数量，这些物质可能会消耗平流层臭氧。其次，受火山脱气影响的树木年轮的硫同位素特征将被用来识别火山的活动和平静时期。这种同位素树轮记录提供了一种新的手段来识别周期性重新活动的火山的活动并确定其年代。在这项为期5年的研究计划中，将培养3名博士生、3名硕士、10名理科学生和1名博士后。我的指导理念是确保更多的初级学生得到我自己的指导和培训，以及更多的高级学生，特别是博士后和高级博士后。这项研究将有助于我的长期目标，即广泛了解岩浆和喷发前和喷发期间的挥发性行为。所获得的知识将提高我们预测火山喷发的能力。

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.