4DVOLC: Magma storage and ascent in volcanic systems via time resolved HPHT x-ray tomographic experiments and numerical modelling of eruption dynamics

火山是地球上最强大和最危险的自然现象之一。800万人生活在火山的阴影下。因此，改善我们目前对火山系统行为的了解，以改进危险评估和风险缓解，对于在活跃的火山地区工作的科学家和政府当局来说是当务之急。该项目的主要目标是建立一个经验受限的岩浆泡化和结晶动力学的定量描述，并将其应用于通过数值模型框架和对自然系统的观察来解决关键的火山学问题。为此，我们将结合现场4D(时间+空间)同步x射线显微层析实验，以可视化和量化HPHT的岩浆结晶和脱气与最先进的数值模拟和对天然火山结构的观察。这种方法将彻底改变实验岩石学和火山学，并将在理解、量化和预测火山喷发及其对社会和气候影响的能力方面产生范式转变。为了实现这一目标，我们计划利用一种新的X射线透明IHPV(内部加热压力容器)的潜力，它被部署在另一项赠款的框架内，以解决困扰地球科学家数十年的基本问题：1)岩浆动力学和深部运输与我们在地表观察到的火山活动和信号之间的关系是什么？2)火山活动是如何发生的，为什么会发生，以及我们如何建模和预测它们？通过开发新的IHPV，我们将通过对不同成分、挥发分和晶体含量的岩浆进行原位4D X射线计算机显微断层成像，对在这种转变中发挥关键作用的岩浆泡化和结晶动力学进行研究。微观尺度上岩浆动力学的4D实验结果将被用来推导出随着冷却和减压速率的变化，在不断演化的结晶和泡囊条件下岩浆粘度的改进的经验规律，然后将利用这些经验规律将其实施为一个大规模的多相、多组分的火山导管中岩浆物理行为的数值模型。该模型将由曼彻斯特大学与来自美国的同事合作开发。然后，整个发现将通过意大利和留尼汪岛经过充分研究的自然火山喷发的观察和测量来验证，并与之进行比较，这两个地区都是危险的、有人居住的活跃火山区的所在地。一旦发生喷发，留尼汪岛很可能在该项目的时间框架内发生，该模型将与当地火山天文台合作使用，以限制喷发预测和实时演变。有了这种全面的方法，该研究项目将产生一个极其可靠的工具，用于调查和量化静止和喷发条件下的火山动力学。火山观测站/利益攸关方将在火山爆发之前和期间使用这种工具，以跟踪火山表面现象(即变形)和喷发方式的变化，并对喷发的演变做出预测。该项目的多学科、开创性和科学性将对英国火山学的未来产生非常强烈的积极影响，并将增加英国在世界范围内的研究潜力。最终，通过充分利用新实验仪器的潜力，该项目将在英国产生一个关键的实验资源，用于未来的新颖研究，涉及自然科学和工程领域不同专业领域的科学家。

Volcanoes are amongst the most powerful and dangerous natural manifestations on Earth. Eight million people live in the shadow of volcanoes. Bettering our current understanding of volcano system behaviour to improve hazard assessment and risk mitigation is therefore imperative for scientists and governmental authorities operating in active volcanic areas. The primary goal of this project is to create an empirically constrained quantitative description of magma vesiculation and crystallisation kinetics and to apply this to address key volcanological questions through a numerical model framework and observations of the natural system. To this aim, we will combine in situ 4D (time+space) synchrotron x-ray microtomographic experiments to visualise and quantify magma crystallisation and degassing at HPHT with state-of-the-art numerical modelling and observations of natural volcanic textures. This approach will revolutionise experimental petrology and volcanology and will create a paradigm shift in the ability to understand, quantify and forecast volcanic eruptions and their impact on society and climate. To achieve this goal, we plan to exploit the potential of a new x-ray transparent IHPV (internally heated pressure vessel), which is deployed in the framework of another grant, to address fundamental questions that have puzzled Earth scientists for decades: 1) what is the relationship between magma dynamics and transport at depth and the volcanic activity and signals that we watch at the surface? 2) how and why do transitions between explosive and effusive volcanic activity occur and how can we model and predict them? By exploiting the new IHPV, we will perform studies on magma vesiculation and crystallisation kinetics, which play a key role in such transitions, by applying in situ 4D x-ray computed microtomography imaging to magmas of different compositions, volatile and crystal content. The results of the 4D experiments on magma kinetics at the micro scale will be used to derive improved empirical laws of magma viscosity under evolving crystallisation and vesiculation conditions as a function of cooling and decompression rates, and then will be implemented with these latter into a large scale multiphase, multicomponent numerical model of the physical behaviour of magma in volcanic conduits. The model will be developed at the University of Manchester in collaboration with colleagues from the US. The overall findings will be then validated by, and compared with, observations and measurements from well studied natural volcanic eruptions in Italy and Reunion, which both host hazardous, inhabited active volcanic areas. In the event of an eruption, which is likely to happen on Reunion within the time frame of the project, the model will be used in collaboration with the local volcano observatory to constrain eruption forecasting and evolution in real time. With this holistic approach, the research project will generate an exceptionally reliable tool for investigating and quantifying volcano dynamics in both quiescent and eruptive conditions. Such tool will be used by volcano observatories/stakeholders before and during eruption breakout for tracking changes in volcano surface phenomena (i.e., deformation) and eruptive style and make predictions on the eruption evolution. The multidisciplinary, ground-breaking, scientific nature of the project will have a very strong positive impact on the future of volcanology in the UK, and will increase the UK potential over worldwide research. Ultimately, by exploiting the full potential of the new experimental apparatus, the project will produce a key experimental resource in the UK for future, novel investigations involving scientists from different areas of expertise within natural sciences and engineering.